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mode 100644 index 501cf29e1d..0000000000 Binary files a/book/src/.gitbook/assets/porep_reward.png and /dev/null differ diff --git a/book/src/.gitbook/assets/validation_client_interest_rates.png b/book/src/.gitbook/assets/validation_client_interest_rates.png deleted file mode 100644 index b17fdf0d39..0000000000 Binary files a/book/src/.gitbook/assets/validation_client_interest_rates.png and /dev/null differ diff --git a/book/src/SUMMARY.md b/book/src/SUMMARY.md index b1b92fade6..8a4827c376 100644 --- a/book/src/SUMMARY.md +++ b/book/src/SUMMARY.md @@ -1,93 +1,81 @@ -# Solana Architecture +# Table of contents -- [Introduction](introduction.md) +* [Introduction](introduction.md) +* [Terminology](terminology.md) +* [Getting Started](getting-started/README.md) + * [Testnet Participation](getting-started/testnet-participation.md) + * [Example Client: Web Wallet](getting-started/webwallet.md) +* [Programming Model](programs/README.md) + * [Example: Tic-Tac-Toe](programs/tictactoe.md) + * [Drones](programs/drones.md) +* [A Solana Cluster](cluster/README.md) + * [Synchronization](cluster/synchronization.md) + * [Leader Rotation](cluster/leader-rotation.md) + * [Fork Generation](cluster/fork-generation.md) + * [Managing Forks](cluster/managing-forks.md) + * [Turbine Block Propagation](cluster/turbine-block-propagation.md) + * [Ledger Replication](cluster/ledger-replication.md) + * [Secure Vote Signing](cluster/vote-signing.md) + * [Stake Delegation and Rewards](cluster/stake-delegation-and-rewards.md) + * [Performance Metrics](cluster/performance-metrics.md) +* [Anatomy of a Validator](validator/README.md) + * [TPU](validator/tpu.md) + * [TVU](validator/tvu/README.md) + * [Blocktree](validator/tvu/blocktree.md) + * [Gossip Service](validator/gossip.md) + * [The Runtime](validator/runtime.md) +* [Anatomy of a Transaction](transaction.md) +* [Running a Validator](running-validator/README.md) + * [Hardware Requirements](running-validator/validator-hardware.md) + * [Choosing a Testnet](running-validator/validator-testnet.md) + * [Installing the Validator Software](running-validator/validator-software.md) + * [Starting a Validator](running-validator/validator-start.md) + * [Staking](running-validator/validator-stake.md) + * [Monitoring a Validator](running-validator/validator-monitor.md) + * [Publishing Validator Info](running-validator/validator-info.md) + * [Troubleshooting](running-validator/validator-troubleshoot.md) + * [FAQ](running-validator/validator-faq.md) +* [Running a Replicator](running-replicator.md) +* [API Reference](api-reference/README.md) + * [Transaction](api-reference/transaction-api.md) + * [Instruction](api-reference/instruction-api.md) + * [Blockstreamer](api-reference/blockstreamer.md) + * [JSON RPC API](api-reference/jsonrpc-api.md) + * [JavaScript API](api-reference/javascript-api.md) + * [solana CLI](api-reference/cli.md) +* [Accepted Design Proposals](proposals/README.md) + * [Ledger Replication](proposals/ledger-replication-to-implement.md) + * [Secure Vote Signing](proposals/vote-signing-to-implement.md) + * [Staking Rewards](proposals/staking-rewards.md) + * [Cluster Economics](proposals/ed_overview/README.md) + * [Validation-client Economics](proposals/ed_overview/ed_validation_client_economics/README.md) + * [State-validation Protocol-based Rewards](proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md) + * [State-validation Transaction Fees](proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_transaction_fees.md) + * [Replication-validation Transaction Fees](proposals/ed_overview/ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md) + * [Validation Stake Delegation](proposals/ed_overview/ed_validation_client_economics/ed_vce_validation_stake_delegation.md) + * [Replication-client Economics](proposals/ed_overview/ed_replication_client_economics/README.md) + * [Storage-replication Rewards](proposals/ed_overview/ed_replication_client_economics/ed_rce_storage_replication_rewards.md) + * [Replication-client Reward Auto-delegation](proposals/ed_overview/ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md) + * [Economic Sustainability](proposals/ed_overview/ed_economic_sustainability.md) + * [Attack Vectors](proposals/ed_overview/ed_attack_vectors.md) + * [Economic Design MVP](proposals/ed_overview/ed_mvp.md) + * [References](proposals/ed_overview/ed_references.md) + * [Cluster Test Framework](proposals/cluster-test-framework.md) + * [Validator](proposals/validator-proposal.md) + * [Simple Payment and State Verification](proposals/simple-payment-and-state-verification.md) + * [Cross-Program Invocation](proposals/cross-program-invocation.md) +* [Implemented Design Proposals](implemented-proposals/README.md) + * [Blocktree](implemented-proposals/blocktree.md) + * [Cluster Software Installation and Updates](implemented-proposals/installer.md) + * [Deterministic Transaction Fees](implemented-proposals/transaction-fees.md) + * [Tower BFT](implemented-proposals/tower-bft.md) + * [Leader-to-Leader Transition](implemented-proposals/leader-leader-transition.md) + * [Leader-to-Validator Transition](implemented-proposals/leader-validator-transition.md) + * [Passive Stake Delegation and Rewards](implemented-proposals/passive-stake-delegation-and-rewards.md) + * [Persistent Account Storage](implemented-proposals/persistent-account-storage.md) + * [Reliable Vote Transmission](implemented-proposals/reliable-vote-transmission.md) + * [Repair Service](implemented-proposals/repair-service.md) + * [Testing Programs](implemented-proposals/testing-programs.md) + * [Credit-only Accounts](implemented-proposals/credit-only-credit-debit-accounts.md) + * [Embedding the Move Langauge](implemented-proposals/embedding-move.md) -- [Terminology](terminology.md) - -- [Getting Started](getting-started.md) - - [Testnet Participation](testnet-participation.md) - - [Example Client: Web Wallet](webwallet.md) - -- [Programming Model](programs.md) - - [Example: Tic-Tac-Toe](tictactoe.md) - - [Drones](drones.md) - -- [A Solana Cluster](cluster.md) - - [Synchronization](synchronization.md) - - [Leader Rotation](leader-rotation.md) - - [Fork Generation](fork-generation.md) - - [Managing Forks](managing-forks.md) - - [Turbine Block Propagation](turbine-block-propagation.md) - - [Ledger Replication](ledger-replication.md) - - [Secure Vote Signing](vote-signing.md) - - [Stake Delegation and Rewards](stake-delegation-and-rewards.md) - - [Performance Metrics](performance-metrics.md) - -- [Anatomy of a Validator](validator.md) - - [TPU](tpu.md) - - [TVU](tvu.md) - - [Blocktree](blocktree.md) - - [Gossip Service](gossip.md) - - [The Runtime](runtime.md) - -- [Anatomy of a Transaction](transaction.md) - -- [Running a Validator](running-validator.md) - - [Hardware Requirements](validator-hardware.md) - - [Choosing a Testnet](validator-testnet.md) - - [Installing the Validator Software](validator-software.md) - - [Starting a Validator](validator-start.md) - - [Staking](validator-stake.md) - - [Monitoring a Validator](validator-monitor.md) - - [Publishing Validator Info](validator-info.md) - - [Troubleshooting](validator-troubleshoot.md) - - [FAQ](validator-faq.md) - -- [Running a Replicator](running-replicator.md) - -- [API Reference](api-reference.md) - - [Transaction](transaction-api.md) - - [Instruction](instruction-api.md) - - [Blockstreamer](blockstreamer.md) - - [JSON RPC API](jsonrpc-api.md) - - [JavaScript API](javascript-api.md) - - [solana CLI](cli.md) - -- [Accepted Design Proposals](proposals.md) - - [Ledger Replication](ledger-replication-to-implement.md) - - [Secure Vote Signing](vote-signing-to-implement.md) - - [Staking Rewards](staking-rewards.md) - - [Cluster Test Framework](cluster-test-framework.md) - - [Validator](validator-proposal.md) - - [Simple Payment and State Verification](simple-payment-and-state-verification.md) - - [Cross-Program Invocation](cross-program-invocation.md) - - [Rent](rent.md) - - [Inter-chain Transaction Verification](interchain-transaction-verification.md) - - [Snapshot Verification](snapshot-verification.md) - -- [Implemented Design Proposals](implemented-proposals.md) - - [Blocktree](blocktree.md) - - [Cluster Software Installation and Updates](installer.md) - - [Cluster Economics](ed_overview.md) - - [Validation-client Economics](ed_validation_client_economics.md) - - [State-validation Protocol-based Rewards](ed_vce_state_validation_protocol_based_rewards.md) - - [State-validation Transaction Fees](ed_vce_state_validation_transaction_fees.md) - - [Replication-validation Transaction Fees](ed_vce_replication_validation_transaction_fees.md) - - [Validation Stake Delegation](ed_vce_validation_stake_delegation.md) - - [Replication-client Economics](ed_replication_client_economics.md) - - [Storage-replication Rewards](ed_rce_storage_replication_rewards.md) - - [Replication-client Reward Auto-delegation](ed_rce_replication_client_reward_auto_delegation.md) - - [Economic Sustainability](ed_economic_sustainability.md) - - [Attack Vectors](ed_attack_vectors.md) - - [Economic Design MVP](ed_mvp.md) - - [References](ed_references.md) - - [Deterministic Transaction Fees](transaction-fees.md) - - [Tower BFT](tower-bft.md) - - [Leader-to-Leader Transition](leader-leader-transition.md) - - [Leader-to-Validator Transition](leader-validator-transition.md) - - [Persistent Account Storage](persistent-account-storage.md) - - [Reliable Vote Transmission](reliable-vote-transmission.md) - - [Repair Service](repair-service.md) - - [Testing Programs](testing-programs.md) - - [Credit-only Accounts](credit-only-credit-debit-accounts.md) - - [Embedding the Move Langauge](embedding-move.md) diff --git a/book/src/api-reference/README.md b/book/src/api-reference/README.md new file mode 100644 index 0000000000..583cbd2826 --- /dev/null +++ b/book/src/api-reference/README.md @@ -0,0 +1,4 @@ +# API Reference + +The following sections contain API references material you may find useful when developing applications utilizing a Solana cluster. + diff --git a/book/src/api-reference/blockstreamer.md b/book/src/api-reference/blockstreamer.md new file mode 100644 index 0000000000..146073efef --- /dev/null +++ b/book/src/api-reference/blockstreamer.md @@ -0,0 +1,28 @@ +# Blockstreamer + +Solana supports a node type called an _blockstreamer_. This fullnode variation is intended for applications that need to observe the data plane without participating in transaction validation or ledger replication. + +A blockstreamer runs without a vote signer, and can optionally stream ledger entries out to a Unix domain socket as they are processed. The JSON-RPC service still functions as on any other node. + +To run a blockstreamer, include the argument `no-signer` and \(optional\) `blockstream` socket location: + +```bash +$ ./multinode-demo/validator-x.sh --no-signer --blockstream +``` + +The stream will output a series of JSON objects: + +* An Entry event JSON object is sent when each ledger entry is processed, with the following fields: + * `dt`, the system datetime, as RFC3339-formatted string + * `t`, the event type, always "entry" + * `s`, the slot height, as unsigned 64-bit integer + * `h`, the tick height, as unsigned 64-bit integer + * `entry`, the entry, as JSON object +* A Block event JSON object is sent when a block is complete, with the following fields: + * `dt`, the system datetime, as RFC3339-formatted string + * `t`, the event type, always "block" + * `s`, the slot height, as unsigned 64-bit integer + * `h`, the tick height, as unsigned 64-bit integer + * `l`, the slot leader id, as base-58 encoded string + * `id`, the block id, as base-58 encoded string + diff --git a/book/src/api-reference/cli.md b/book/src/api-reference/cli.md new file mode 100644 index 0000000000..65bcc8b5c0 --- /dev/null +++ b/book/src/api-reference/cli.md @@ -0,0 +1,370 @@ +# solana CLI + +The [solana-cli crate](https://crates.io/crates/solana-cli) provides a command-line interface tool for Solana + +## Examples + +### Get Pubkey + +```bash +// Command +$ solana address + +// Return + +``` + +### Airdrop Lamports + +```bash +// Command +$ solana airdrop 123 + +// Return +"Your balance is: 123" +``` + +### Get Balance + +```bash +// Command +$ solana balance + +// Return +"Your balance is: 123" +``` + +### Confirm Transaction + +```bash +// Command +$ solana confirm + +// Return +"Confirmed" / "Not found" / "Transaction failed with error " +``` + +### Deploy program + +```bash +// Command +$ solana deploy + +// Return + +``` + +### Unconditional Immediate Transfer + +```bash +// Command +$ solana pay 123 + +// Return + +``` + +### Post-Dated Transfer + +```bash +// Command +$ solana pay 123 \ + --after 2018-12-24T23:59:00 --require-timestamp-from + +// Return +{signature: , processId: } +``` + +_`require-timestamp-from` is optional. If not provided, the transaction will expect a timestamp signed by this wallet's secret key_ + +### Authorized Transfer + +A third party must send a signature to unlock the lamports. + +```bash +// Command +$ solana pay 123 \ + --require-signature-from + +// Return +{signature: , processId: } +``` + +### Post-Dated and Authorized Transfer + +```bash +// Command +$ solana pay 123 \ + --after 2018-12-24T23:59 --require-timestamp-from \ + --require-signature-from + +// Return +{signature: , processId: } +``` + +### Multiple Witnesses + +```bash +// Command +$ solana pay 123 \ + --require-signature-from \ + --require-signature-from + +// Return +{signature: , processId: } +``` + +### Cancelable Transfer + +```bash +// Command +$ solana pay 123 \ + --require-signature-from \ + --cancelable + +// Return +{signature: , processId: } +``` + +### Cancel Transfer + +```bash +// Command +$ solana cancel + +// Return + +``` + +### Send Signature + +```bash +// Command +$ solana send-signature + +// Return + +``` + +### Indicate Elapsed Time + +Use the current system time: + +```bash +// Command +$ solana send-timestamp + +// Return + +``` + +Or specify some other arbitrary timestamp: + +```bash +// Command +$ solana send-timestamp --date 2018-12-24T23:59:00 + +// Return + +``` + +## Usage + +```text +solana 0.12.0 + +USAGE: + solana [FLAGS] [OPTIONS] [SUBCOMMAND] + +FLAGS: + -h, --help Prints help information + --rpc-tls Enable TLS for the RPC endpoint + -V, --version Prints version information + +OPTIONS: + --drone-host Drone host to use [default: same as --host] + --drone-port Drone port to use [default: 9900] + -n, --host Host to use for both RPC and drone [default: 127.0.0.1] + -k, --keypair /path/to/id.json + --rpc-host RPC host to use [default: same as --host] + --rpc-port RPC port to use [default: 8899] + +SUBCOMMANDS: + address Get your public key + airdrop Request a batch of lamports + balance Get your balance + cancel Cancel a transfer + confirm Confirm transaction by signature + deploy Deploy a program + get-transaction-count Get current transaction count + help Prints this message or the help of the given subcommand(s) + pay Send a payment + send-signature Send a signature to authorize a transfer + send-timestamp Send a timestamp to unlock a transfer +``` + +```text +solana-address +Get your public key + +USAGE: + solana address + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information +``` + +```text +solana-airdrop +Request a batch of lamports + +USAGE: + solana airdrop + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +ARGS: + The number of lamports to request +``` + +```text +solana-balance +Get your balance + +USAGE: + solana balance + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information +``` + +```text +solana-cancel +Cancel a transfer + +USAGE: + solana cancel + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +ARGS: + The process id of the transfer to cancel +``` + +```text +solana-confirm +Confirm transaction by signature + +USAGE: + solana confirm + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +ARGS: + The transaction signature to confirm +``` + +```text +solana-deploy +Deploy a program + +USAGE: + solana deploy + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +ARGS: + /path/to/program.o +``` + +```text +solana-fees +Display current cluster fees + +USAGE: + solana fees + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information +``` + +```text +solana-get-transaction-count +Get current transaction count + +USAGE: + solana get-transaction-count + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information +``` + +```text +solana-pay +Send a payment + +USAGE: + solana pay [FLAGS] [OPTIONS] + +FLAGS: + --cancelable + -h, --help Prints help information + -V, --version Prints version information + +OPTIONS: + --after A timestamp after which transaction will execute + --require-timestamp-from Require timestamp from this third party + --require-signature-from ... Any third party signatures required to unlock the lamports + +ARGS: + The pubkey of recipient + The number of lamports to send +``` + +```text +solana-send-signature +Send a signature to authorize a transfer + +USAGE: + solana send-signature + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +ARGS: + The pubkey of recipient + The process id of the transfer to authorize +``` + +```text +solana-send-timestamp +Send a timestamp to unlock a transfer + +USAGE: + solana send-timestamp [OPTIONS] + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +OPTIONS: + --date Optional arbitrary timestamp to apply + +ARGS: + The pubkey of recipient + The process id of the transfer to unlock +``` + diff --git a/book/src/api-reference/instruction-api.md b/book/src/api-reference/instruction-api.md new file mode 100644 index 0000000000..e460c9a9f0 --- /dev/null +++ b/book/src/api-reference/instruction-api.md @@ -0,0 +1,38 @@ +# Instruction + +For the purposes of building a [Transaction](../transaction.md), a more verbose instruction format is used: + +* **Instruction:** + * **program\_id:** The pubkey of the on-chain program that executes the + + instruction + + * **accounts:** An ordered list of accounts that should be passed to + + the program processing the instruction, including metadata detailing + + if an account is a signer of the transaction and if it is a credit + + only account. + + * **data:** A byte array that is passed to the program executing the + + instruction + +A more compact form is actually included in a `Transaction`: + +* **CompiledInstruction:** + * **program\_id\_index:** The index of the `program_id` in the + + `account_keys` list + + * **accounts:** An ordered list of indices into `account_keys` + + specifying the accounds that should be passed to the program + + processing the instruction. + + * **data:** A byte array that is passed to the program executing the + + instruction + diff --git a/book/src/api-reference/javascript-api.md b/book/src/api-reference/javascript-api.md new file mode 100644 index 0000000000..5f891d0fc0 --- /dev/null +++ b/book/src/api-reference/javascript-api.md @@ -0,0 +1,4 @@ +# JavaScript API + +See [solana-web3](https://solana-labs.github.io/solana-web3.js/). + diff --git a/book/src/api-reference/jsonrpc-api.md b/book/src/api-reference/jsonrpc-api.md new file mode 100644 index 0000000000..f20a1a0cd5 --- /dev/null +++ b/book/src/api-reference/jsonrpc-api.md @@ -0,0 +1,788 @@ +# JSON RPC API + +Solana nodes accept HTTP requests using the [JSON-RPC 2.0](https://www.jsonrpc.org/specification) specification. + +To interact with a Solana node inside a JavaScript application, use the [solana-web3.js](https://github.com/solana-labs/solana-web3.js) library, which gives a convenient interface for the RPC methods. + +## RPC HTTP Endpoint + +**Default port:** 8899 eg. [http://localhost:8899](http://localhost:8899), [http://192.168.1.88:8899](http://192.168.1.88:8899) + +## RPC PubSub WebSocket Endpoint + +**Default port:** 8900 eg. ws://localhost:8900, [http://192.168.1.88:8900](http://192.168.1.88:8900) + +## Methods + +* [confirmTransaction](jsonrpc-api.md#confirmtransaction) +* [getAccountInfo](jsonrpc-api.md#getaccountinfo) +* [getBalance](jsonrpc-api.md#getbalance) +* [getClusterNodes](jsonrpc-api.md#getclusternodes) +* [getEpochInfo](jsonrpc-api.md#getepochinfo) +* [getGenesisBlockhash](jsonrpc-api.md#getgenesisblockhash) +* [getLeaderSchedule](jsonrpc-api.md#getleaderschedule) +* [getProgramAccounts](jsonrpc-api.md#getprogramaccounts) +* [getRecentBlockhash](jsonrpc-api.md#getrecentblockhash) +* [getSignatureStatus](jsonrpc-api.md#getsignaturestatus) +* [getSlot](jsonrpc-api.md#getslot) +* [getSlotLeader](jsonrpc-api.md#getslotleader) +* [getSlotsPerSegment](jsonrpc-api.md#getslotspersegment) +* [getStorageTurn](jsonrpc-api.md#getstorageturn) +* [getStorageTurnRate](jsonrpc-api.md#getstorageturnrate) +* [getNumBlocksSinceSignatureConfirmation](jsonrpc-api.md#getnumblockssincesignatureconfirmation) +* [getTransactionCount](jsonrpc-api.md#gettransactioncount) +* [getTotalSupply](jsonrpc-api.md#gettotalsupply) +* [getVersion](jsonrpc-api.md#getversion) +* [getVoteAccounts](jsonrpc-api.md#getvoteaccounts) +* [requestAirdrop](jsonrpc-api.md#requestairdrop) +* [sendTransaction](jsonrpc-api.md#sendtransaction) +* [startSubscriptionChannel](jsonrpc-api.md#startsubscriptionchannel) +* [Subscription Websocket](jsonrpc-api.md#subscription-websocket) + * [accountSubscribe](jsonrpc-api.md#accountsubscribe) + * [accountUnsubscribe](jsonrpc-api.md#accountunsubscribe) + * [programSubscribe](jsonrpc-api.md#programsubscribe) + * [programUnsubscribe](jsonrpc-api.md#programunsubscribe) + * [signatureSubscribe](jsonrpc-api.md#signaturesubscribe) + * [signatureUnsubscribe](jsonrpc-api.md#signatureunsubscribe) + +## Request Formatting + +To make a JSON-RPC request, send an HTTP POST request with a `Content-Type: application/json` header. The JSON request data should contain 4 fields: + +* `jsonrpc`, set to `"2.0"` +* `id`, a unique client-generated identifying integer +* `method`, a string containing the method to be invoked +* `params`, a JSON array of ordered parameter values + +Example using curl: + +```bash +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getBalance", "params":["83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri"]}' 192.168.1.88:8899 +``` + +The response output will be a JSON object with the following fields: + +* `jsonrpc`, matching the request specification +* `id`, matching the request identifier +* `result`, requested data or success confirmation + +Requests can be sent in batches by sending an array of JSON-RPC request objects as the data for a single POST. + +## Definitions + +* Hash: A SHA-256 hash of a chunk of data. +* Pubkey: The public key of a Ed25519 key-pair. +* Signature: An Ed25519 signature of a chunk of data. +* Transaction: A Solana instruction signed by a client key-pair. + +## JSON RPC API Reference + +### confirmTransaction + +Returns a transaction receipt + +#### Parameters: + +* `string` - Signature of Transaction to confirm, as base-58 encoded string + +#### Results: + +* `boolean` - Transaction status, true if Transaction is confirmed + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"confirmTransaction", "params":["5VERv8NMvzbJMEkV8xnrLkEaWRtSz9CosKDYjCJjBRnbJLgp8uirBgmQpjKhoR4tjF3ZpRzrFmBV6UjKdiSZkQUW"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":true,"id":1} +``` + +### getAccountInfo + +Returns all information associated with the account of provided Pubkey + +#### Parameters: + +* `string` - Pubkey of account to query, as base-58 encoded string + +#### Results: + +The result field will be a JSON object with the following sub fields: + +* `lamports`, number of lamports assigned to this account, as a signed 64-bit integer +* `owner`, array of 32 bytes representing the program this account has been assigned to +* `data`, array of bytes representing any data associated with the account +* `executable`, boolean indicating if the account contains a program \(and is strictly read-only\) + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getAccountInfo", "params":["2gVkYWexTHR5Hb2aLeQN3tnngvWzisFKXDUPrgMHpdST"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":{"executable":false,"owner":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"lamports":1,"data":[3,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,20,0,0,0,0,0,0,0,50,48,53,48,45,48,49,45,48,49,84,48,48,58,48,48,58,48,48,90,252,10,7,28,246,140,88,177,98,82,10,227,89,81,18,30,194,101,199,16,11,73,133,20,246,62,114,39,20,113,189,32,50,0,0,0,0,0,0,0,247,15,36,102,167,83,225,42,133,127,82,34,36,224,207,130,109,230,224,188,163,33,213,13,5,117,211,251,65,159,197,51,0,0,0,0,0,0]},"id":1} +``` + +### getBalance + +Returns the balance of the account of provided Pubkey + +#### Parameters: + +* `string` - Pubkey of account to query, as base-58 encoded string + +#### Results: + +* `integer` - quantity, as a signed 64-bit integer + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getBalance", "params":["83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":0,"id":1} +``` + +### getClusterNodes + +Returns information about all the nodes participating in the cluster + +#### Parameters: + +None + +#### Results: + +The result field will be an array of JSON objects, each with the following sub fields: + +* `pubkey` - Node public key, as base-58 encoded string +* `gossip` - Gossip network address for the node +* `tpu` - TPU network address for the node +* `rpc` - JSON RPC network address for the node, or `null` if the JSON RPC service is not enabled + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getClusterNodes"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":[{"gossip":"10.239.6.48:8001","pubkey":"9QzsJf7LPLj8GkXbYT3LFDKqsj2hHG7TA3xinJHu8epQ","rpc":"10.239.6.48:8899","tpu":"10.239.6.48:8856"}],"id":1} +``` + +### getEpochInfo + +Returns information about the current epoch + +#### Parameters: + +None + +#### Results: + +The result field will be an object with the following fields: + +* `epoch`, the current epoch +* `slotIndex`, the current slot relative to the start of the current epoch +* `slotsInEpoch`, the number of slots in this epoch + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getEpochInfo"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":{"epoch":3,"slotIndex":126,"slotsInEpoch":256},"id":1} +``` + +### getGenesisBlockhash + +Returns the genesis block hash + +#### Parameters: + +None + +#### Results: + +* `string` - a Hash as base-58 encoded string + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getGenesisBlockhash"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"GH7ome3EiwEr7tu9JuTh2dpYWBJK3z69Xm1ZE3MEE6JC","id":1} +``` + +### getLeaderSchedule + +Returns the leader schedule for the current epoch + +#### Parameters: + +None + +#### Results: + +The result field will be an array of leader public keys \(as base-58 encoded strings\) for each slot in the current epoch + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getLeaderSchedule"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":[...],"id":1} +``` + +### getProgramAccounts + +Returns all accounts owned by the provided program Pubkey + +#### Parameters: + +* `string` - Pubkey of program, as base-58 encoded string + +#### Results: + +The result field will be an array of arrays. Each sub array will contain: + +* `string` - the account Pubkey as base-58 encoded string and a JSON object, with the following sub fields: +* `lamports`, number of lamports assigned to this account, as a signed 64-bit integer +* `owner`, array of 32 bytes representing the program this account has been assigned to +* `data`, array of bytes representing any data associated with the account +* `executable`, boolean indicating if the account contains a program \(and is strictly read-only\) + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getProgramAccounts", "params":["8nQwAgzN2yyUzrukXsCa3JELBYqDQrqJ3UyHiWazWxHR"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":[["BqGKYtAKu69ZdWEBtZHh4xgJY1BYa2YBiBReQE3pe383", {"executable":false,"owner":[50,28,250,90,221,24,94,136,147,165,253,136,1,62,196,215,225,34,222,212,99,84,202,223,245,13,149,99,149,231,91,96],"lamports":1,"data":[]], ["4Nd1mBQtrMJVYVfKf2PJy9NZUZdTAsp7D4xWLs4gDB4T", {"executable":false,"owner":[50,28,250,90,221,24,94,136,147,165,253,136,1,62,196,215,225,34,222,212,99,84,202,223,245,13,149,99,149,231,91,96],"lamports":10,"data":[]]]},"id":1} +``` + +### getRecentBlockhash + +Returns a recent block hash from the ledger, and a fee schedule that can be used to compute the cost of submitting a transaction using it. + +#### Parameters: + +None + +#### Results: + +An array consisting of + +* `string` - a Hash as base-58 encoded string +* `FeeCalculator object` - the fee schedule for this block hash + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getRecentBlockhash"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":["GH7ome3EiwEr7tu9JuTh2dpYWBJK3z69Xm1ZE3MEE6JC",{"lamportsPerSignature": 0}],"id":1} +``` + +### getSignatureStatus + +Returns the status of a given signature. This method is similar to [confirmTransaction](jsonrpc-api.md#confirmtransaction) but provides more resolution for error events. + +#### Parameters: + +* `string` - Signature of Transaction to confirm, as base-58 encoded string + +#### Results: + +* `null` - Unknown transaction +* `object` - Transaction status: + * `"Ok": null` - Transaction was successful + * `"Err": ` - Transaction failed with TransactionError [TransactionError definitions](https://github.com/solana-labs/solana/blob/master/sdk/src/transaction.rs#L14) + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getSignatureStatus", "params":["5VERv8NMvzbJMEkV8xnrLkEaWRtSz9CosKDYjCJjBRnbJLgp8uirBgmQpjKhoR4tjF3ZpRzrFmBV6UjKdiSZkQUW"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"SignatureNotFound","id":1} +``` + +### getSlot + +Returns the current slot the node is processing + +#### Parameters: + +None + +#### Results: + +* `u64` - Current slot + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getSlot"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"1234","id":1} +``` + +### getSlotLeader + +Returns the current slot leader + +#### Parameters: + +None + +#### Results: + +* `string` - Node Id as base-58 encoded string + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getSlotLeader"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"ENvAW7JScgYq6o4zKZwewtkzzJgDzuJAFxYasvmEQdpS","id":1} +``` + +### getSlotsPerSegment + +Returns the current storage segment size in terms of slots + +#### Parameters: + +None + +#### Results: + +* `u64` - Number of slots in a storage segment + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getSlotsPerSegment"}' http://localhost:8899 +// Result +{"jsonrpc":"2.0","result":"1024","id":1} +``` + +### getStorageTurn + +Returns the current storage turn's blockhash and slot + +#### Parameters: + +None + +#### Results: + +An array consisting of + +* `string` - a Hash as base-58 encoded string indicating the blockhash of the turn slot +* `u64` - the current storage turn slot + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getStorageTurn"}' http://localhost:8899 + // Result +{"jsonrpc":"2.0","result":["GH7ome3EiwEr7tu9JuTh2dpYWBJK3z69Xm1ZE3MEE6JC", "2048"],"id":1} +``` + +### getStorageTurnRate + +Returns the current storage turn rate in terms of slots per turn + +#### Parameters: + +None + +#### Results: + +* `u64` - Number of slots in storage turn + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getStorageTurnRate"}' http://localhost:8899 + // Result +{"jsonrpc":"2.0","result":"1024","id":1} +``` + +### getNumBlocksSinceSignatureConfirmation + +Returns the current number of blocks since signature has been confirmed. + +#### Parameters: + +* `string` - Signature of Transaction to confirm, as base-58 encoded string + +#### Results: + +* `integer` - count, as unsigned 64-bit integer + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getNumBlocksSinceSignatureConfirmation", "params":["5VERv8NMvzbJMEkV8xnrLkEaWRtSz9CosKDYjCJjBRnbJLgp8uirBgmQpjKhoR4tjF3ZpRzrFmBV6UjKdiSZkQUW"]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":8,"id":1} +``` + +### getTransactionCount + +Returns the current Transaction count from the ledger + +#### Parameters: + +None + +#### Results: + +* `integer` - count, as unsigned 64-bit integer + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getTransactionCount"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":268,"id":1} +``` + +### getTotalSupply + +Returns the current total supply in Lamports + +#### Parameters: + +None + +#### Results: + +* `integer` - Total supply, as unsigned 64-bit integer + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getTotalSupply"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":10126,"id":1} +``` + +### getVersion + +Returns the current solana versions running on the node + +#### Parameters: + +None + +#### Results: + +The result field will be a JSON object with the following sub fields: + +* `solana-core`, software version of solana-core + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getVersion"}' http://localhost:8899 +// Result +{"jsonrpc":"2.0","result":{"solana-core": "0.17.2"},"id":1} +``` + +### getVoteAccounts + +Returns the account info and associated stake for all the voting accounts in the current bank. + +#### Parameters: + +None + +#### Results: + +The result field will be a JSON object of `current` and `delinquent` accounts, each containing an array of JSON objects with the following sub fields: + +* `votePubkey` - Vote account public key, as base-58 encoded string +* `nodePubkey` - Node public key, as base-58 encoded string +* `activatedStake` - the stake, in lamports, delegated to this vote account and active in this epoch +* `epochVoteAccount` - bool, whether the vote account is staked for this epoch +* `commission`, an 8-bit integer used as a fraction \(commission/MAX\_U8\) for rewards payout +* `lastVote` - Most recent slot voted on by this vote account + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getVoteAccounts"}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":{"current":[{"commission":0,"epochVoteAccount":true,"nodePubkey":"B97CCUW3AEZFGy6uUg6zUdnNYvnVq5VG8PUtb2HayTDD","lastVote":147,"activatedStake":42,"votePubkey":"3ZT31jkAGhUaw8jsy4bTknwBMP8i4Eueh52By4zXcsVw"}],"delinquent":[{"commission":127,"epochVoteAccount":false,"nodePubkey":"6ZPxeQaDo4bkZLRsdNrCzchNQr5LN9QMc9sipXv9Kw8f","lastVote":0,"activatedStake":0,"votePubkey":"CmgCk4aMS7KW1SHX3s9K5tBJ6Yng2LBaC8MFov4wx9sm"}]},"id":1} +``` + +### requestAirdrop + +Requests an airdrop of lamports to a Pubkey + +#### Parameters: + +* `string` - Pubkey of account to receive lamports, as base-58 encoded string +* `integer` - lamports, as a signed 64-bit integer + +#### Results: + +* `string` - Transaction Signature of airdrop, as base-58 encoded string + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"requestAirdrop", "params":["83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri", 50]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"5VERv8NMvzbJMEkV8xnrLkEaWRtSz9CosKDYjCJjBRnbJLgp8uirBgmQpjKhoR4tjF3ZpRzrFmBV6UjKdiSZkQUW","id":1} +``` + +### sendTransaction + +Creates new transaction + +#### Parameters: + +* `array` - array of octets containing a fully-signed Transaction + +#### Results: + +* `string` - Transaction Signature, as base-58 encoded string + +#### Example: + +```bash +// Request +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"sendTransaction", "params":[[61, 98, 55, 49, 15, 187, 41, 215, 176, 49, 234, 229, 228, 77, 129, 221, 239, 88, 145, 227, 81, 158, 223, 123, 14, 229, 235, 247, 191, 115, 199, 71, 121, 17, 32, 67, 63, 209, 239, 160, 161, 2, 94, 105, 48, 159, 235, 235, 93, 98, 172, 97, 63, 197, 160, 164, 192, 20, 92, 111, 57, 145, 251, 6, 40, 240, 124, 194, 149, 155, 16, 138, 31, 113, 119, 101, 212, 128, 103, 78, 191, 80, 182, 234, 216, 21, 121, 243, 35, 100, 122, 68, 47, 57, 13, 39, 0, 0, 0, 0, 50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 50, 0, 0, 0, 0, 0, 0, 0, 40, 240, 124, 194, 149, 155, 16, 138, 31, 113, 119, 101, 212, 128, 103, 78, 191, 80, 182, 234, 216, 21, 121, 243, 35, 100, 122, 68, 47, 57, 11, 12, 106, 49, 74, 226, 201, 16, 161, 192, 28, 84, 124, 97, 190, 201, 171, 186, 6, 18, 70, 142, 89, 185, 176, 154, 115, 61, 26, 163, 77, 1, 88, 98, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]]}' http://localhost:8899 + +// Result +{"jsonrpc":"2.0","result":"2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b","id":1} +``` + +### Subscription Websocket + +After connect to the RPC PubSub websocket at `ws://
/`: + +* Submit subscription requests to the websocket using the methods below +* Multiple subscriptions may be active at once +* All subscriptions take an optional `confirmations` parameter, which defines + + how many confirmed blocks the node should wait before sending a notification. + + The greater the number, the more likely the notification is to represent + + consensus across the cluster, and the less likely it is to be affected by + + forking or rollbacks. If unspecified, the default value is 0; the node will + + send a notification as soon as it witnesses the event. The maximum + + `confirmations` wait length is the cluster's `MAX_LOCKOUT_HISTORY`, which + + represents the economic finality of the chain. + +### accountSubscribe + +Subscribe to an account to receive notifications when the lamports or data for a given account public key changes + +#### Parameters: + +* `string` - account Pubkey, as base-58 encoded string +* `integer` - optional, number of confirmed blocks to wait before notification. + + Default: 0, Max: `MAX_LOCKOUT_HISTORY` \(greater integers rounded down\) + +#### Results: + +* `integer` - Subscription id \(needed to unsubscribe\) + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"accountSubscribe", "params":["CM78CPUeXjn8o3yroDHxUtKsZZgoy4GPkPPXfouKNH12"]} + +{"jsonrpc":"2.0", "id":1, "method":"accountSubscribe", "params":["CM78CPUeXjn8o3yroDHxUtKsZZgoy4GPkPPXfouKNH12", 15]} + +// Result +{"jsonrpc": "2.0","result": 0,"id": 1} +``` + +#### Notification Format: + +```bash +{"jsonrpc": "2.0","method": "accountNotification", "params": {"result": {"executable":false,"owner":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"lamports":1,"data":[3,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,20,0,0,0,0,0,0,0,50,48,53,48,45,48,49,45,48,49,84,48,48,58,48,48,58,48,48,90,252,10,7,28,246,140,88,177,98,82,10,227,89,81,18,30,194,101,199,16,11,73,133,20,246,62,114,39,20,113,189,32,50,0,0,0,0,0,0,0,247,15,36,102,167,83,225,42,133,127,82,34,36,224,207,130,109,230,224,188,163,33,213,13,5,117,211,251,65,159,197,51,0,0,0,0,0,0]},"subscription":0}} +``` + +### accountUnsubscribe + +Unsubscribe from account change notifications + +#### Parameters: + +* `integer` - id of account Subscription to cancel + +#### Results: + +* `bool` - unsubscribe success message + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"accountUnsubscribe", "params":[0]} + +// Result +{"jsonrpc": "2.0","result": true,"id": 1} +``` + +### programSubscribe + +Subscribe to a program to receive notifications when the lamports or data for a given account owned by the program changes + +#### Parameters: + +* `string` - program\_id Pubkey, as base-58 encoded string +* `integer` - optional, number of confirmed blocks to wait before notification. + + Default: 0, Max: `MAX_LOCKOUT_HISTORY` \(greater integers rounded down\) + +#### Results: + +* `integer` - Subscription id \(needed to unsubscribe\) + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"programSubscribe", "params":["9gZbPtbtHrs6hEWgd6MbVY9VPFtS5Z8xKtnYwA2NynHV"]} + +{"jsonrpc":"2.0", "id":1, "method":"programSubscribe", "params":["9gZbPtbtHrs6hEWgd6MbVY9VPFtS5Z8xKtnYwA2NynHV", 15]} + +// Result +{"jsonrpc": "2.0","result": 0,"id": 1} +``` + +#### Notification Format: + +* `string` - account Pubkey, as base-58 encoded string +* `object` - account info JSON object \(see [getAccountInfo](jsonrpc-api.md#getaccountinfo) for field details\) + + ```bash + {"jsonrpc":"2.0","method":"programNotification","params":{{"result":["8Rshv2oMkPu5E4opXTRyuyBeZBqQ4S477VG26wUTFxUM",{"executable":false,"lamports":1,"owner":[129,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"data":[1,1,1,0,0,0,0,0,0,0,20,0,0,0,0,0,0,0,50,48,49,56,45,49,50,45,50,52,84,50,51,58,53,57,58,48,48,90,235,233,39,152,15,44,117,176,41,89,100,86,45,61,2,44,251,46,212,37,35,118,163,189,247,84,27,235,178,62,55,89,0,0,0,0,50,0,0,0,0,0,0,0,235,233,39,152,15,44,117,176,41,89,100,86,45,61,2,44,251,46,212,37,35,118,163,189,247,84,27,235,178,62,45,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}],"subscription":0}} + ``` + +### programUnsubscribe + +Unsubscribe from program-owned account change notifications + +#### Parameters: + +* `integer` - id of account Subscription to cancel + +#### Results: + +* `bool` - unsubscribe success message + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"programUnsubscribe", "params":[0]} + +// Result +{"jsonrpc": "2.0","result": true,"id": 1} +``` + +### signatureSubscribe + +Subscribe to a transaction signature to receive notification when the transaction is confirmed On `signatureNotification`, the subscription is automatically cancelled + +#### Parameters: + +* `string` - Transaction Signature, as base-58 encoded string +* `integer` - optional, number of confirmed blocks to wait before notification. + + Default: 0, Max: `MAX_LOCKOUT_HISTORY` \(greater integers rounded down\) + +#### Results: + +* `integer` - subscription id \(needed to unsubscribe\) + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"signatureSubscribe", "params":["2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b"]} + +{"jsonrpc":"2.0", "id":1, "method":"signatureSubscribe", "params":["2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b", 15]} + +// Result +{"jsonrpc": "2.0","result": 0,"id": 1} +``` + +#### Notification Format: + +```bash +{"jsonrpc": "2.0","method": "signatureNotification", "params": {"result": "Confirmed","subscription":0}} +``` + +### signatureUnsubscribe + +Unsubscribe from signature confirmation notification + +#### Parameters: + +* `integer` - subscription id to cancel + +#### Results: + +* `bool` - unsubscribe success message + +#### Example: + +```bash +// Request +{"jsonrpc":"2.0", "id":1, "method":"signatureUnsubscribe", "params":[0]} + +// Result +{"jsonrpc": "2.0","result": true,"id": 1} +``` + diff --git a/book/src/api-reference/transaction-api.md b/book/src/api-reference/transaction-api.md new file mode 100644 index 0000000000..ba74ecc28e --- /dev/null +++ b/book/src/api-reference/transaction-api.md @@ -0,0 +1,63 @@ +# Transaction + +## Components of a `Transaction` + +* **Transaction:** + * **message:** Defines the transaction + * **header:** Details the account types of and signatures required by + + the transaction + + * **num\_required\_signatures:** The total number of signatures + + required to make the transaction valid. + + * **num\_credit\_only\_signed\_accounts:** The last + + `num_credit_only_signed_accounts` signatures refer to signing + + credit only accounts. Credit only accounts can be used concurrently + + by multiple parallel transactions, but their balance may only be + + increased, and their account data is read-only. + + * **num\_credit\_only\_unsigned\_accounts:** The last + + `num_credit_only_unsigned_accounts` pubkeys in `account_keys` refer + + to non-signing credit only accounts + + * **account\_keys:** List of pubkeys used by the transaction, including + + by the instructions and for signatures. The first + + `num_required_signatures` pubkeys must sign the transaction. + + * **recent\_blockhash:** The ID of a recent ledger entry. Validators will + + reject transactions with a `recent_blockhash` that is too old. + + * **instructions:** A list of [instructions](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/instruction.md) that are + + run sequentially and committed in one atomic transaction if all + + succeed. + * **signatures:** A list of signatures applied to the transaction. The + + list is always of length `num_required_signatures`, and the signature + + at index `i` corresponds to the pubkey at index `i` in `account_keys`. + + The list is initialized with empty signatures \(i.e. zeros\), and + + populated as signatures are added. + +## Transaction Signing + +A `Transaction` is signed by using an ed25519 keypair to sign the serialization of the `message`. The resulting signature is placed at the index of `signatures` matching the index of the keypair's pubkey in `account_keys`. + +## Transaction Serialization + +`Transaction`s \(and their `message`s\) are serialized and deserialized using the [bincode](https://crates.io/crates/bincode) crate with a non-standard vector serialization that uses only one byte for the length if it can be encoded in 7 bits, 2 bytes if it fits in 14 bits, or 3 bytes if it requires 15 or 16 bits. The vector serialization is defined by Solana's [short-vec](https://github.com/solana-labs/solana/blob/master/sdk/src/short_vec.rs). + diff --git a/book/src/cluster/README.md b/book/src/cluster/README.md new file mode 100644 index 0000000000..5fe19fe8fe --- /dev/null +++ b/book/src/cluster/README.md @@ -0,0 +1,41 @@ +# A Solana Cluster + +A Solana cluster is a set of fullnodes working together to serve client transactions and maintain the integrity of the ledger. Many clusters may coexist. When two clusters share a common genesis block, they attempt to converge. Otherwise, they simply ignore the existence of the other. Transactions sent to the wrong one are quietly rejected. In this chapter, we'll discuss how a cluster is created, how nodes join the cluster, how they share the ledger, how they ensure the ledger is replicated, and how they cope with buggy and malicious nodes. + +## Creating a Cluster + +Before starting any fullnodes, one first needs to create a _genesis block_. The block contains entries referencing two public keys, a _mint_ and a _bootstrap leader_. The fullnode holding the bootstrap leader's secret key is responsible for appending the first entries to the ledger. It initializes its internal state with the mint's account. That account will hold the number of native tokens defined by the genesis block. The second fullnode then contacts the bootstrap leader to register as a _validator_ or _replicator_. Additional fullnodes then register with any registered member of the cluster. + +A validator receives all entries from the leader and submits votes confirming those entries are valid. After voting, the validator is expected to store those entries until replicator nodes submit proofs that they have stored copies of it. Once the validator observes a sufficient number of copies exist, it deletes its copy. + +## Joining a Cluster + +Validators and replicators enter the cluster via registration messages sent to its _control plane_. The control plane is implemented using a _gossip_ protocol, meaning that a node may register with any existing node, and expect its registration to propagate to all nodes in the cluster. The time it takes for all nodes to synchronize is proportional to the square of the number of nodes participating in the cluster. Algorithmically, that's considered very slow, but in exchange for that time, a node is assured that it eventually has all the same information as every other node, and that that information cannot be censored by any one node. + +## Sending Transactions to a Cluster + +Clients send transactions to any fullnode's Transaction Processing Unit \(TPU\) port. If the node is in the validator role, it forwards the transaction to the designated leader. If in the leader role, the node bundles incoming transactions, timestamps them creating an _entry_, and pushes them onto the cluster's _data plane_. Once on the data plane, the transactions are validated by validator nodes and replicated by replicator nodes, effectively appending them to the ledger. + +## Confirming Transactions + +A Solana cluster is capable of subsecond _confirmation_ for up to 150 nodes with plans to scale up to hundreds of thousands of nodes. Once fully implemented, confirmation times are expected to increase only with the logarithm of the number of validators, where the logarithm's base is very high. If the base is one thousand, for example, it means that for the first thousand nodes, confirmation will be the duration of three network hops plus the time it takes the slowest validator of a supermajority to vote. For the next million nodes, confirmation increases by only one network hop. + +Solana defines confirmation as the duration of time from when the leader timestamps a new entry to the moment when it recognizes a supermajority of ledger votes. + +A gossip network is much too slow to achieve subsecond confirmation once the network grows beyond a certain size. The time it takes to send messages to all nodes is proportional to the square of the number of nodes. If a blockchain wants to achieve low confirmation and attempts to do it using a gossip network, it will be forced to centralize to just a handful of nodes. + +Scalable confirmation can be achieved using the follow combination of techniques: + +1. Timestamp transactions with a VDF sample and sign the timestamp. +2. Split the transactions into batches, send each to separate nodes and have + + each node share its batch with its peers. + +3. Repeat the previous step recursively until all nodes have all batches. + +Solana rotates leaders at fixed intervals, called _slots_. Each leader may only produce entries during its allotted slot. The leader therefore timestamps transactions so that validators may lookup the public key of the designated leader. The leader then signs the timestamp so that a validator may verify the signature, proving the signer is owner of the designated leader's public key. + +Next, transactions are broken into batches so that a node can send transactions to multiple parties without making multiple copies. If, for example, the leader needed to send 60 transactions to 6 nodes, it would break that collection of 60 into batches of 10 transactions and send one to each node. This allows the leader to put 60 transactions on the wire, not 60 transactions for each node. Each node then shares its batch with its peers. Once the node has collected all 6 batches, it reconstructs the original set of 60 transactions. + +A batch of transactions can only be split so many times before it is so small that header information becomes the primary consumer of network bandwidth. At the time of this writing, the approach is scaling well up to about 150 validators. To scale up to hundreds of thousands of validators, each node can apply the same technique as the leader node to another set of nodes of equal size. We call the technique _data plane fanout_; learn more in the [data plan fanout](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/data-plane-fanout.md) section. + diff --git a/book/src/cluster/fork-generation.md b/book/src/cluster/fork-generation.md new file mode 100644 index 0000000000..3c02df9530 --- /dev/null +++ b/book/src/cluster/fork-generation.md @@ -0,0 +1,81 @@ +# Fork Generation + +The chapter describes how forks naturally occur as a consequence of [leader rotation](leader-rotation.md). + +## Overview + +Nodes take turns being leader and generating the PoH that encodes state changes. The cluster can tolerate loss of connection to any leader by synthesizing what the leader _**would**_ have generated had it been connected but not ingesting any state changes. The possible number of forks is thereby limited to a "there/not-there" skip list of forks that may arise on leader rotation slot boundaries. At any given slot, only a single leader's transactions will be accepted. + +## Message Flow + +1. Transactions are ingested by the current leader. +2. Leader filters valid transactions. +3. Leader executes valid transactions updating its state. +4. Leader packages transactions into entries based off its current PoH slot. +5. Leader transmits the entries to validator nodes \(in signed blobs\) + 1. The PoH stream includes ticks; empty entries that indicate liveness of + + the leader and the passage of time on the cluster. + + 2. A leader's stream begins with the tick entries necessary complete the PoH + + back to the leaders most recently observed prior leader slot. +6. Validators retransmit entries to peers in their set and to further + + downstream nodes. + +7. Validators validate the transactions and execute them on their state. +8. Validators compute the hash of the state. +9. At specific times, i.e. specific PoH tick counts, validators transmit votes + + to the leader. + + 1. Votes are signatures of the hash of the computed state at that PoH tick + + count + + 2. Votes are also propagated via gossip + +10. Leader executes the votes as any other transaction and broadcasts them to + + the cluster. + +11. Validators observe their votes and all the votes from the cluster. + +## Partitions, Forks + +Forks can arise at PoH tick counts that correspond to a vote. The next leader may not have observed the last vote slot and may start their slot with generated virtual PoH entries. These empty ticks are generated by all nodes in the cluster at a cluster-configured rate for hashes/per/tick `Z`. + +There are only two possible versions of the PoH during a voting slot: PoH with `T` ticks and entries generated by the current leader, or PoH with just ticks. The "just ticks" version of the PoH can be thought of as a virtual ledger, one that all nodes in the cluster can derive from the last tick in the previous slot. + +Validators can ignore forks at other points \(e.g. from the wrong leader\), or slash the leader responsible for the fork. + +Validators vote based on a greedy choice to maximize their reward described in [Tower BFT](../implemented-proposals/tower-bft.md). + +### Validator's View + +#### Time Progression + +The diagram below represents a validator's view of the PoH stream with possible forks over time. L1, L2, etc. are leader slots, and `E`s represent entries from that leader during that leader's slot. The `x`s represent ticks only, and time flows downwards in the diagram. + +![Fork generation](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/fork-generation.svg) + +Note that an `E` appearing on 2 forks at the same slot is a slashable condition, so a validator observing `E3` and `E3'` can slash L3 and safely choose `x` for that slot. Once a validator commits to a forks, other forks can be discarded below that tick count. For any slot, validators need only consider a single "has entries" chain or a "ticks only" chain to be proposed by a leader. But multiple virtual entries may overlap as they link back to the a previous slot. + +#### Time Division + +It's useful to consider leader rotation over PoH tick count as time division of the job of encoding state for the cluster. The following table presents the above tree of forks as a time-divided ledger. + +| leader slot | L1 | L2 | L3 | L4 | L5 | +| :--- | :--- | :--- | :--- | :--- | :--- | +| data | E1 | E2 | E3 | E4 | E5 | +| ticks since prev | | | | x | xx | + +Note that only data from leader L3 will be accepted during leader slot L3. Data from L3 may include "catchup" ticks back to a slot other than L2 if L3 did not observe L2's data. L4 and L5's transmissions include the "ticks to prev" PoH entries. + +This arrangement of the network data streams permits nodes to save exactly this to the ledger for replay, restart, and checkpoints. + +### Leader's View + +When a new leader begins a slot, it must first transmit any PoH \(ticks\) required to link the new slot with the most recently observed and voted slot. The fork the leader proposes would link the current slot to a previous fork that the leader has voted on with virtual ticks. + diff --git a/book/src/cluster/leader-rotation.md b/book/src/cluster/leader-rotation.md new file mode 100644 index 0000000000..8a7f783b3b --- /dev/null +++ b/book/src/cluster/leader-rotation.md @@ -0,0 +1,98 @@ +# Leader Rotation + +At any given moment, a cluster expects only one fullnode to produce ledger entries. By having only one leader at a time, all validators are able to replay identical copies of the ledger. The drawback of only one leader at a time, however, is that a malicious leader is capable of censoring votes and transactions. Since censoring cannot be distinguished from the network dropping packets, the cluster cannot simply elect a single node to hold the leader role indefinitely. Instead, the cluster minimizes the influence of a malicious leader by rotating which node takes the lead. + +Each validator selects the expected leader using the same algorithm, described below. When the validator receives a new signed ledger entry, it can be certain that entry was produced by the expected leader. The order of slots which each leader is assigned a slot is called a _leader schedule_. + +## Leader Schedule Rotation + +A validator rejects blocks that are not signed by the _slot leader_. The list of identities of all slot leaders is called a _leader schedule_. The leader schedule is recomputed locally and periodically. It assigns slot leaders for a duration of time called an _epoch_. The schedule must be computed far in advance of the slots it assigns, such that the ledger state it uses to compute the schedule is finalized. That duration is called the _leader schedule offset_. Solana sets the offset to the duration of slots until the next epoch. That is, the leader schedule for an epoch is calculated from the ledger state at the start of the previous epoch. The offset of one epoch is fairly arbitrary and assumed to be sufficiently long such that all validators will have finalized their ledger state before the next schedule is generated. A cluster may choose to shorten the offset to reduce the time between stake changes and leader schedule updates. + +While operating without partitions lasting longer than an epoch, the schedule only needs to be generated when the root fork crosses the epoch boundary. Since the schedule is for the next epoch, any new stakes committed to the root fork will not be active until the next epoch. The block used for generating the leader schedule is the first block to cross the epoch boundary. + +Without a partition lasting longer than an epoch, the cluster will work as follows: + +1. A validator continuously updates its own root fork as it votes. +2. The validator updates its leader schedule each time the slot height crosses an epoch boundary. + +For example: + +The epoch duration is 100 slots. The root fork is updated from fork computed at slot height 99 to a fork computed at slot height 102. Forks with slots at height 100,101 were skipped because of failures. The new leader schedule is computed using fork at slot height 102. It is active from slot 200 until it is updated again. + +No inconsistency can exist because every validator that is voting with the cluster has skipped 100 and 101 when its root passes 102. All validators, regardless of voting pattern, would be committing to a root that is either 102, or a descendant of 102. + +### Leader Schedule Rotation with Epoch Sized Partitions. + +The duration of the leader schedule offset has a direct relationship to the likelihood of a cluster having an inconsistent view of the correct leader schedule. + +Consider the following scenario: + +Two partitions that are generating half of the blocks each. Neither is coming to a definitive supermajority fork. Both will cross epoch 100 and 200 without actually committing to a root and therefore a cluster wide commitment to a new leader schedule. + +In this unstable scenario, multiple valid leader schedules exist. + +* A leader schedule is generated for every fork whose direct parent is in the previous epoch. +* The leader schedule is valid after the start of the next epoch for descendant forks until it is updated. + +Each partition's schedule will diverge after the partition lasts more than an epoch. For this reason, the epoch duration should be selected to be much much larger then slot time and the expected length for a fork to be committed to root. + +After observing the cluster for a sufficient amount of time, the leader schedule offset can be selected based on the median partition duration and its standard deviation. For example, an offset longer then the median partition duration plus six standard deviations would reduce the likelihood of an inconsistent ledger schedule in the cluster to 1 in 1 million. + +## Leader Schedule Generation at Genesis + +The genesis block declares the first leader for the first epoch. This leader ends up scheduled for the first two epochs because the leader schedule is also generated at slot 0 for the next epoch. The length of the first two epochs can be specified in the genesis block as well. The minimum length of the first epochs must be greater than or equal to the maximum rollback depth as defined in [Tower BFT](../implemented-proposals/tower-bft.md). + +## Leader Schedule Generation Algorithm + +Leader schedule is generated using a predefined seed. The process is as follows: + +1. Periodically use the PoH tick height \(a monotonically increasing counter\) to + + seed a stable pseudo-random algorithm. + +2. At that height, sample the bank for all the staked accounts with leader + + identities that have voted within a cluster-configured number of ticks. The + + sample is called the _active set_. + +3. Sort the active set by stake weight. +4. Use the random seed to select nodes weighted by stake to create a + + stake-weighted ordering. + +5. This ordering becomes valid after a cluster-configured number of ticks. + +## Schedule Attack Vectors + +### Seed + +The seed that is selected is predictable but unbiasable. There is no grinding attack to influence its outcome. + +### Active Set + +A leader can bias the active set by censoring validator votes. Two possible ways exist for leaders to censor the active set: + +* Ignore votes from validators +* Refuse to vote for blocks with votes from validators + +To reduce the likelihood of censorship, the active set is calculated at the leader schedule offset boundary over an _active set sampling duration_. The active set sampling duration is long enough such that votes will have been collected by multiple leaders. + +### Staking + +Leaders can censor new staking transactions or refuse to validate blocks with new stakes. This attack is similar to censorship of validator votes. + +### Validator operational key loss + +Leaders and validators are expected to use ephemeral keys for operation, and stake owners authorize the validators to do work with their stake via delegation. + +The cluster should be able to recover from the loss of all the ephemeral keys used by leaders and validators, which could occur through a common software vulnerability shared by all the nodes. Stake owners should be able to vote directly co-sign a validator vote even though the stake is currently delegated to a validator. + +## Appending Entries + +The lifetime of a leader schedule is called an _epoch_. The epoch is split into _slots_, where each slot has a duration of `T` PoH ticks. + +A leader transmits entries during its slot. After `T` ticks, all the validators switch to the next scheduled leader. Validators must ignore entries sent outside a leader's assigned slot. + +All `T` ticks must be observed by the next leader for it to build its own entries on. If entries are not observed \(leader is down\) or entries are invalid \(leader is buggy or malicious\), the next leader must produce ticks to fill the previous leader's slot. Note that the next leader should do repair requests in parallel, and postpone sending ticks until it is confident other validators also failed to observe the previous leader's entries. If a leader incorrectly builds on its own ticks, the leader following it must replace all its ticks. + diff --git a/book/src/cluster/ledger-replication.md b/book/src/cluster/ledger-replication.md new file mode 100644 index 0000000000..6d7060303b --- /dev/null +++ b/book/src/cluster/ledger-replication.md @@ -0,0 +1,269 @@ +# Ledger Replication + +At full capacity on a 1gbps network solana will generate 4 petabytes of data per year. To prevent the network from centralizing around validators that have to store the full data set this protocol proposes a way for mining nodes to provide storage capacity for pieces of the data. + +The basic idea to Proof of Replication is encrypting a dataset with a public symmetric key using CBC encryption, then hash the encrypted dataset. The main problem with the naive approach is that a dishonest storage node can stream the encryption and delete the data as it's hashed. The simple solution is to periodically regenerate the hash based on a signed PoH value. This ensures that all the data is present during the generation of the proof and it also requires validators to have the entirety of the encrypted data present for verification of every proof of every identity. So the space required to validate is `number_of_proofs * data_size` + +## Optimization with PoH + +Our improvement on this approach is to randomly sample the encrypted segments faster than it takes to encrypt, and record the hash of those samples into the PoH ledger. Thus the segments stay in the exact same order for every PoRep and verification can stream the data and verify all the proofs in a single batch. This way we can verify multiple proofs concurrently, each one on its own CUDA core. The total space required for verification is `1_ledger_segment + 2_cbc_blocks * number_of_identities` with core count equal to `number_of_identities`. We use a 64-byte chacha CBC block size. + +## Network + +Validators for PoRep are the same validators that are verifying transactions. If a replicator can prove that a validator verified a fake PoRep, then the validator will not receive a reward for that storage epoch. + +Replicators are specialized _light clients_. They download a part of the ledger \(a.k.a Segment\) and store it, and provide PoReps of storing the ledger. For each verified PoRep replicators earn a reward of sol from the mining pool. + +## Constraints + +We have the following constraints: + +* Verification requires generating the CBC blocks. That requires space of 2 + + blocks per identity, and 1 CUDA core per identity for the same dataset. So as + + many identities at once should be batched with as many proofs for those + + identities verified concurrently for the same dataset. + +* Validators will randomly sample the set of storage proofs to the set that + + they can handle, and only the creators of those chosen proofs will be + + rewarded. The validator can run a benchmark whenever its hardware configuration + + changes to determine what rate it can validate storage proofs. + +## Validation and Replication Protocol + +### Constants + +1. SLOTS\_PER\_SEGMENT: Number of slots in a segment of ledger data. The + + unit of storage for a replicator. + +2. NUM\_KEY\_ROTATION\_SEGMENTS: Number of segments after which replicators + + regenerate their encryption keys and select a new dataset to store. + +3. NUM\_STORAGE\_PROOFS: Number of storage proofs required for a storage proof + + claim to be successfully rewarded. + +4. RATIO\_OF\_FAKE\_PROOFS: Ratio of fake proofs to real proofs that a storage + + mining proof claim has to contain to be valid for a reward. + +5. NUM\_STORAGE\_SAMPLES: Number of samples required for a storage mining + + proof. + +6. NUM\_CHACHA\_ROUNDS: Number of encryption rounds performed to generate + + encrypted state. + +7. NUM\_SLOTS\_PER\_TURN: Number of slots that define a single storage epoch or + + a "turn" of the PoRep game. + +### Validator behavior + +1. Validators join the network and begin looking for replicator accounts at each + + storage epoch/turn boundary. + +2. Every turn, Validators sign the PoH value at the boundary and use that signature + + to randomly pick proofs to verify from each storage account found in the turn boundary. + + This signed value is also submitted to the validator's storage account and will be used by + + replicators at a later stage to cross-verify. + +3. Every `NUM_SLOTS_PER_TURN` slots the validator advertises the PoH value. This is value + + is also served to Replicators via RPC interfaces. + +4. For a given turn N, all validations get locked out until turn N+3 \(a gap of 2 turn/epoch\). + + At which point all validations during that turn are available for reward collection. + +5. Any incorrect validations will be marked during the turn in between. + +### Replicator behavior + +1. Since a replicator is somewhat of a light client and not downloading all the + + ledger data, they have to rely on other validators and replicators for information. + + Any given validator may or may not be malicious and give incorrect information, although + + there are not any obvious attack vectors that this could accomplish besides having the + + replicator do extra wasted work. For many of the operations there are a number of options + + depending on how paranoid a replicator is: + + * \(a\) replicator can ask a validator + * \(b\) replicator can ask multiple validators + * \(c\) replicator can ask other replicators + * \(d\) replicator can subscribe to the full transaction stream and generate + + the information itself \(assuming the slot is recent enough\) + + * \(e\) replicator can subscribe to an abbreviated transaction stream to + + generate the information itself \(assuming the slot is recent enough\) + +2. A replicator obtains the PoH hash corresponding to the last turn with its slot. +3. The replicator signs the PoH hash with its keypair. That signature is the + + seed used to pick the segment to replicate and also the encryption key. The + + replicator mods the signature with the slot to get which segment to + + replicate. + +4. The replicator retrives the ledger by asking peer validators and + + replicators. See 6.5. + +5. The replicator then encrypts that segment with the key with chacha algorithm + + in CBC mode with `NUM_CHACHA_ROUNDS` of encryption. + +6. The replicator initializes a chacha rng with the a signed recent PoH value as + + the seed. + +7. The replicator generates `NUM_STORAGE_SAMPLES` samples in the range of the + + entry size and samples the encrypted segment with sha256 for 32-bytes at each + + offset value. Sampling the state should be faster than generating the encrypted + + segment. + +8. The replicator sends a PoRep proof transaction which contains its sha state + + at the end of the sampling operation, its seed and the samples it used to the + + current leader and it is put onto the ledger. + +9. During a given turn the replicator should submit many proofs for the same segment + + and based on the `RATIO_OF_FAKE_PROOFS` some of those proofs must be fake. + +10. As the PoRep game enters the next turn, the replicator must submit a + + transaction with the mask of which proofs were fake during the last turn. This + + transaction will define the rewards for both replicators and validators. + +11. Finally for a turn N, as the PoRep game enters turn N + 3, replicator's proofs for + + turn N will be counted towards their rewards. + +### The PoRep Game + +The Proof of Replication game has 4 primary stages. For each "turn" multiple PoRep games can be in progress but each in a different stage. + +The 4 stages of the PoRep Game are as follows: + +1. Proof submission stage + * Replicators: submit as many proofs as possible during this stage + * Validators: No-op +2. Proof verification stage + * Replicators: No-op + * Validators: Select replicators and verify their proofs from the previous turn +3. Proof challenge stage + * Replicators: Submit the proof mask with justifications \(for fake proofs submitted 2 turns ago\) + * Validators: No-op +4. Reward collection stage + * Replicators: Collect rewards for 3 turns ago + * Validators: Collect rewards for 3 turns ago + +For each turn of the PoRep game, both Validators and Replicators evaluate each stage. The stages are run as separate transactions on the storage program. + +### Finding who has a given block of ledger + +1. Validators monitor the turns in the PoRep game and look at the rooted bank + + at turn boundaries for any proofs. + +2. Validators maintain a map of ledger segments and corresponding replicator public keys. + + The map is updated when a Validator processes a replicator's proofs for a segment. + + The validator provides an RPC interface to access the this map. Using this API, clients + + can map a segment to a replicator's network address \(correlating it via cluster\_info table\). + + The clients can then send repair requests to the replicator to retrieve segments. + +3. Validators would need to invalidate this list every N turns. + +## Sybil attacks + +For any random seed, we force everyone to use a signature that is derived from a PoH hash at the turn boundary. Everyone uses the same count, so the same PoH hash is signed by every participant. The signatures are then each cryptographically tied to the keypair, which prevents a leader from grinding on the resulting value for more than 1 identity. + +Since there are many more client identities then encryption identities, we need to split the reward for multiple clients, and prevent Sybil attacks from generating many clients to acquire the same block of data. To remain BFT we want to avoid a single human entity from storing all the replications of a single chunk of the ledger. + +Our solution to this is to force the clients to continue using the same identity. If the first round is used to acquire the same block for many client identities, the second round for the same client identities will force a redistribution of the signatures, and therefore PoRep identities and blocks. Thus to get a reward for replicators need to store the first block for free and the network can reward long lived client identities more than new ones. + +## Validator attacks + +* If a validator approves fake proofs, replicator can easily out them by + + showing the initial state for the hash. + +* If a validator marks real proofs as fake, no on-chain computation can be done + + to distinguish who is correct. Rewards would have to rely on the results from + + multiple validators to catch bad actors and replicators from being denied rewards. + +* Validator stealing mining proof results for itself. The proofs are derived + + from a signature from a replicator, since the validator does not know the + + private key used to generate the encryption key, it cannot be the generator of + + the proof. + +## Reward incentives + +Fake proofs are easy to generate but difficult to verify. For this reason, PoRep proof transactions generated by replicators may require a higher fee than a normal transaction to represent the computational cost required by validators. + +Some percentage of fake proofs are also necessary to receive a reward from storage mining. + +## Notes + +* We can reduce the costs of verification of PoRep by using PoH, and actually + + make it feasible to verify a large number of proofs for a global dataset. + +* We can eliminate grinding by forcing everyone to sign the same PoH hash and + + use the signatures as the seed + +* The game between validators and replicators is over random blocks and random + + encryption identities and random data samples. The goal of randomization is + + to prevent colluding groups from having overlap on data or validation. + +* Replicator clients fish for lazy validators by submitting fake proofs that + + they can prove are fake. + +* To defend against Sybil client identities that try to store the same block we + + force the clients to store for multiple rounds before receiving a reward. + +* Validators should also get rewarded for validating submitted storage proofs + + as incentive for storing the ledger. They can only validate proofs if they + + are storing that slice of the ledger. + diff --git a/book/src/cluster/managing-forks.md b/book/src/cluster/managing-forks.md new file mode 100644 index 0000000000..fbd8d63535 --- /dev/null +++ b/book/src/cluster/managing-forks.md @@ -0,0 +1,35 @@ +# Managing Forks + +The ledger is permitted to fork at slot boundaries. The resulting data structure forms a tree called a _blocktree_. When the fullnode interprets the blocktree, it must maintain state for each fork in the chain. We call each instance an _active fork_. It is the responsibility of a fullnode to weigh those forks, such that it may eventually select a fork. + +A fullnode selects a fork by submiting a vote to a slot leader on that fork. The vote commits the fullnode for a duration of time called a _lockout period_. The fullnode is not permitted to vote on a different fork until that lockout period expires. Each subsequent vote on the same fork doubles the length of the lockout period. After some cluster-configured number of votes \(currently 32\), the length of the lockout period reaches what's called _max lockout_. Until the max lockout is reached, the fullnode has the option to wait until the lockout period is over and then vote on another fork. When it votes on another fork, it performs a operation called _rollback_, whereby the state rolls back in time to a shared checkpoint and then jumps forward to the tip of the fork that it just voted on. The maximum distance that a fork may roll back is called the _rollback depth_. Rollback depth is the number of votes required to achieve max lockout. Whenever a fullnode votes, any checkpoints beyond the rollback depth become unreachable. That is, there is no scenario in which the fullnode will need to roll back beyond rollback depth. It therefore may safely _prune_ unreachable forks and _squash_ all checkpoints beyond rollback depth into the root checkpoint. + +## Active Forks + +An active fork is as a sequence of checkpoints that has a length at least one longer than the rollback depth. The shortest fork will have a length exactly one longer than the rollback depth. For example: + +![Forks](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/forks.svg) + +The following sequences are _active forks_: + +* {4, 2, 1} +* {5, 2, 1} +* {6, 3, 1} +* {7, 3, 1} + +## Pruning and Squashing + +A fullnode may vote on any checkpoint in the tree. In the diagram above, that's every node except the leaves of the tree. After voting, the fullnode prunes nodes that fork from a distance farther than the rollback depth and then takes the opportunity to minimize its memory usage by squashing any nodes it can into the root. + +Starting from the example above, wth a rollback depth of 2, consider a vote on 5 versus a vote on 6. First, a vote on 5: + +![Forks after pruning](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/forks-pruned.svg) + +The new root is 2, and any active forks that are not descendants from 2 are pruned. + +Alternatively, a vote on 6: + +![Forks](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/forks-pruned2.svg) + +The tree remains with a root of 1, since the active fork starting at 6 is only 2 checkpoints from the root. + diff --git a/book/src/cluster/performance-metrics.md b/book/src/cluster/performance-metrics.md new file mode 100644 index 0000000000..a97fd08b3e --- /dev/null +++ b/book/src/cluster/performance-metrics.md @@ -0,0 +1,16 @@ +# Performance Metrics + +Solana cluster performance is measured as average number of transactions per second that the network can sustain \(TPS\). And, how long it takes for a transaction to be confirmed by super majority of the cluster \(Confirmation Time\). + +Each cluster node maintains various counters that are incremented on certain events. These counters are periodically uploaded to a cloud based database. Solana's metrics dashboard fetches these counters, and computes the performance metrics and displays it on the dashboard. + +## TPS + +Each node's bank runtime maintains a count of transactions that it has processed. The dashboard first calculates the median count of transactions across all metrics enabled nodes in the cluster. The median cluster transaction count is then averaged over a 2 second period and displayed in the TPS time series graph. The dashboard also shows the Mean TPS, Max TPS and Total Transaction Count stats which are all calculated from the median transaction count. + +## Confirmation Time + +Each validator node maintains a list of active ledger forks that are visible to the node. A fork is considered to be frozen when the node has received and processed all entries corresponding to the fork. A fork is considered to be confirmed when it receives cumulative super majority vote, and when one of its children forks is frozen. + +The node assigns a timestamp to every new fork, and computes the time it took to confirm the fork. This time is reflected as validator confirmation time in performance metrics. The performance dashboard displays the average of each validator node's confirmation time as a time series graph. + diff --git a/book/src/cluster/stake-delegation-and-rewards.md b/book/src/cluster/stake-delegation-and-rewards.md new file mode 100644 index 0000000000..ca0a9cde79 --- /dev/null +++ b/book/src/cluster/stake-delegation-and-rewards.md @@ -0,0 +1,209 @@ +# Stake Delegation and Rewards + +Stakers are rewarded for helping to validate the ledger. They do this by delegating their stake to validator nodes. Those validators do the legwork of replaying the ledger and send votes to a per-node vote account to which stakers can delegate their stakes. The rest of the cluster uses those stake-weighted votes to select a block when forks arise. Both the validator and staker need some economic incentive to play their part. The validator needs to be compensated for its hardware and the staker needs to be compensated for the risk of getting its stake slashed. The economics are covered in [staking rewards](../proposals/staking-rewards.md). This chapter, on the other hand, describes the underlying mechanics of its implementation. + +## Basic Design + +The general idea is that the validator owns a Vote account. The Vote account tracks validator votes, counts validator generated credits, and provides any additional validator specific state. The Vote account is not aware of any stakes delegated to it and has no staking weight. + +A separate Stake account \(created by a staker\) names a Vote account to which the stake is delegated. Rewards generated are proportional to the amount of lamports staked. The Stake account is owned by the staker only. Some portion of the lamports stored in this account are the stake. + +## Passive Delegation + +Any number of Stake accounts can delegate to a single Vote account without an interactive action from the identity controlling the Vote account or submitting votes to the account. + +The total stake allocated to a Vote account can be calculated by the sum of all the Stake accounts that have the Vote account pubkey as the `StakeState::Stake::voter_pubkey`. + +## Vote and Stake accounts + +The rewards process is split into two on-chain programs. The Vote program solves the problem of making stakes slashable. The Stake account acts as custodian of the rewards pool, and provides passive delegation. The Stake program is responsible for paying out each staker once the staker proves to the Stake program that its delegate has participated in validating the ledger. + +### VoteState + +VoteState is the current state of all the votes the validator has submitted to the network. VoteState contains the following state information: + +* `votes` - The submitted votes data structure. +* `credits` - The total number of rewards this vote program has generated over its lifetime. +* `root_slot` - The last slot to reach the full lockout commitment necessary for rewards. +* `commission` - The commission taken by this VoteState for any rewards claimed by staker's Stake accounts. This is the percentage ceiling of the reward. +* Account::lamports - The accumulated lamports from the commission. These do not count as stakes. +* `authorized_vote_signer` - Only this identity is authorized to submit votes. This field can only modified by this identity. + +### VoteInstruction::Initialize + +* `account[0]` - RW - The VoteState + + `VoteState::authorized_vote_signer` is initialized to `account[0]` + + other VoteState members defaulted + +### VoteInstruction::AuthorizeVoteSigner\(Pubkey\) + +* `account[0]` - RW - The VoteState + + `VoteState::authorized_vote_signer` is set to to `Pubkey`, the transaction must by + + signed by the Vote account's current `authorized_vote_signer`. + + + `VoteInstruction::AuthorizeVoter` allows a staker to choose a signing service + + for its votes. That service is responsible for ensuring the vote won't cause + + the staker to be slashed. + +### VoteInstruction::Vote\(Vec\) + +* `account[0]` - RW - The VoteState + + `VoteState::lockouts` and `VoteState::credits` are updated according to voting lockout rules see [Tower BFT](../implemented-proposals/tower-bft.md) + +* `account[1]` - RO - A list of some N most recent slots and their hashes for the vote to be verified against. + +### StakeState + +A StakeState takes one of three forms, StakeState::Uninitialized, StakeState::Stake and StakeState::RewardsPool. + +### StakeState::Stake + +StakeState::Stake is the current delegation preference of the **staker** and contains the following state information: + +* Account::lamports - The lamports available for staking. +* `stake` - the staked amount \(subject to warm up and cool down\) for generating rewards, always less than or equal to Account::lamports +* `voter_pubkey` - The pubkey of the VoteState instance the lamports are delegated to. +* `credits_observed` - The total credits claimed over the lifetime of the program. +* `activated` - the epoch at which this stake was activated/delegated. The full stake will be counted after warm up. +* `deactivated` - the epoch at which this stake will be completely de-activated, which is `cool down` epochs after StakeInstruction::Deactivate is issued. + +### StakeState::RewardsPool + +To avoid a single network wide lock or contention in redemption, 256 RewardsPools are part of genesis under pre-determined keys, each with std::u64::MAX credits to be able to satisfy redemptions according to point value. + +The Stakes and the RewardsPool are accounts that are owned by the same `Stake` program. + +### StakeInstruction::DelegateStake\(u64\) + +The Stake account is moved from Uninitialized to StakeState::Stake form. This is how stakers choose their initial delegate validator node and activate their stake account lamports. + +* `account[0]` - RW - The StakeState::Stake instance. `StakeState::Stake::credits_observed` is initialized to `VoteState::credits`, `StakeState::Stake::voter_pubkey` is initialized to `account[1]`, `StakeState::Stake::stake` is initialized to the u64 passed as an argument above, `StakeState::Stake::activated` is initialized to current Bank epoch, and `StakeState::Stake::deactivated` is initialized to std::u64::MAX +* `account[1]` - R - The VoteState instance. +* `account[2]` - R - sysvar::current account, carries information about current Bank epoch +* `account[3]` - R - stake\_api::Config accoount, carries warmup, cooldown, and slashing configuration + +### StakeInstruction::RedeemVoteCredits + +The staker or the owner of the Stake account sends a transaction with this instruction to claim rewards. + +The Vote account and the Stake account pair maintain a lifetime counter of total rewards generated and claimed. Rewards are paid according to a point value supplied by the Bank from inflation. A `point` is one credit \* one staked lamport, rewards paid are proportional to the number of lamports staked. + +* `account[0]` - RW - The StakeState::Stake instance that is redeeming rewards. +* `account[1]` - R - The VoteState instance, must be the same as `StakeState::voter_pubkey` +* `account[2]` - RW - The StakeState::RewardsPool instance that will fulfill the request \(picked at random\). +* `account[3]` - R - sysvar::rewards account from the Bank that carries point value. +* `account[4]` - R - sysvar::stake\_history account from the Bank that carries stake warmup/cooldown history + +Reward is paid out for the difference between `VoteState::credits` to `StakeState::Stake::credits_observed`, multiplied by `sysvar::rewards::Rewards::validator_point_value`. `StakeState::Stake::credits_observed` is updated to`VoteState::credits`. The commission is deposited into the Vote account token balance, and the reward is deposited to the Stake account token balance. + +```text +let credits_to_claim = vote_state.credits - stake_state.credits_observed; +stake_state.credits_observed = vote_state.credits; +``` + +`credits_to_claim` is used to compute the reward and commission, and `StakeState::Stake::credits_observed` is updated to the latest `VoteState::credits` value. + +### StakeInstruction::Deactivate + +A staker may wish to withdraw from the network. To do so he must first deactivate his stake, and wait for cool down. + +* `account[0]` - RW - The StakeState::Stake instance that is deactivating, the transaction must be signed by this key. +* `account[1]` - R - The VoteState instance to which this stake is delegated, required in case of slashing +* `account[2]` - R - sysvar::current account from the Bank that carries current epoch + +StakeState::Stake::deactivated is set to the current epoch + cool down. The account's stake will ramp down to zero by that epoch, and Account::lamports will be available for withdrawal. + +### StakeInstruction::Withdraw\(u64\) + +Lamports build up over time in a Stake account and any excess over activated stake can be withdrawn. + +* `account[0]` - RW - The StakeState::Stake from which to withdraw, the transaction must be signed by this key. +* `account[1]` - RW - Account that should be credited with the withdrawn lamports. +* `account[2]` - R - sysvar::current account from the Bank that carries current epoch, to calculate stake. +* `account[3]` - R - sysvar::stake\_history account from the Bank that carries stake warmup/cooldown history + +## Benefits of the design + +* Single vote for all the stakers. +* Clearing of the credit variable is not necessary for claiming rewards. +* Each delegated stake can claim its rewards independently. +* Commission for the work is deposited when a reward is claimed by the delegated stake. + +## Example Callflow + +![Passive Staking Callflow](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/passive-staking-callflow.svg) + +## Staking Rewards + +The specific mechanics and rules of the validator rewards regime is outlined here. Rewards are earned by delegating stake to a validator that is voting correctly. Voting incorrectly exposes that validator's stakes to [slashing](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/staking-and-rewards.md). + +### Basics + +The network pays rewards from a portion of network [inflation](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/inflation.md). The number of lamports available to pay rewards for an epoch is fixed and must be evenly divided among all staked nodes according to their relative stake weight and participation. The weighting unit is called a [point](../terminology.md#point). + +Rewards for an epoch are not available until the end of that epoch. + +At the end of each epoch, the total number of points earned during the epoch is summed and used to divide the rewards portion of epoch inflation to arrive at a point value. This value is recorded in the bank in a [sysvar](../terminology.md#sysvar) that maps epochs to point values. + +During redemption, the stake program counts the points earned by the stake for each epoch, multiplies that by the epoch's point value, and transfers lamports in that amount from a rewards account into the stake and vote accounts according to the vote account's commission setting. + +### Economics + +Point value for an epoch depends on aggregate network participation. If participation in an epoch drops off, point values are higher for those that do participate. + +### Earning credits + +Validators earn one vote credit for every correct vote that exceeds maximum lockout, i.e. every time the validator's vote account retires a slot from its lockout list, making that vote a root for the node. + +Stakers who have delegated to that validator earn points in proportion to their stake. Points earned is the product of vote credits and stake. + +### Stake warmup, cooldown, withdrawal + +Stakes, once delegated, do not become effective immediately. They must first pass through a warm up period. During this period some portion of the stake is considered "effective", the rest is considered "activating". Changes occur on epoch boundaries. + +The stake program limits the rate of change to total network stake, reflected in the stake program's `config::warmup_rate` \(typically 15% per epoch\). + +The amount of stake that can be warmed up each epoch is a function of the previous epoch's total effective stake, total activating stake, and the stake program's configured warmup rate. + +Cooldown works the same way. Once a stake is deactivated, some part of it is considered "effective", and also "deactivating". As the stake cools down, it continues to earn rewards and be exposed to slashing, but it also becomes available for withdrawal. + +Bootstrap stakes are not subject to warmup. + +Rewards are paid against the "effective" portion of the stake for that epoch. + +#### Warmup example + +Consider the situation of a single stake of 1,000 activated at epoch N, with network warmup rate of 20%, and a quiescent total network stake at epoch N of 2,000. + +At epoch N+1, the amount available to be activated for the network is 400 \(20% of 200\), and at epoch N, this example stake is the only stake activating, and so is entitled to all of the warmup room available. + +| epoch | effective | activating | total effective | total activating | +| :--- | ---: | ---: | ---: | ---: | +| N-1 | | | 2,000 | 0 | +| N | 0 | 1,000 | 2,000 | 1,000 | +| N+1 | 400 | 600 | 2,400 | 600 | +| N+2 | 880 | 120 | 2,880 | 120 | +| N+3 | 1000 | 0 | 3,000 | 0 | + +Were 2 stakes \(X and Y\) to activate at epoch N, they would be awarded a portion of the 20% in proportion to their stakes. At each epoch effective and activating for each stake is a function of the previous epoch's state. + +| epoch | X eff | X act | Y eff | Y act | total effective | total activating | +| :--- | ---: | ---: | ---: | ---: | ---: | ---: | +| N-1 | | | | | 2,000 | 0 | +| N | 0 | 1,000 | 0 | 200 | 2,000 | 1,200 | +| N+1 | 320 | 680 | 80 | 120 | 2,400 | 800 | +| N+2 | 728 | 272 | 152 | 48 | 2,880 | 320 | +| N+3 | 1000 | 0 | 200 | 0 | 3,200 | 0 | + +### Withdrawal + +As rewards are earned lamports can be withdrawn from a stake account. Only lamports in excess of effective+activating stake may be withdrawn at any time. This means that during warmup, effectively no stake can be withdrawn. During cooldown, any tokens in excess of effective stake may be withdrawn \(activating == 0\); + diff --git a/book/src/cluster/synchronization.md b/book/src/cluster/synchronization.md new file mode 100644 index 0000000000..75a0a46d27 --- /dev/null +++ b/book/src/cluster/synchronization.md @@ -0,0 +1,27 @@ +# Synchronization + +Fast, reliable synchronization is the biggest reason Solana is able to achieve such high throughput. Traditional blockchains synchronize on large chunks of transactions called blocks. By synchronizing on blocks, a transaction cannot be processed until a duration called "block time" has passed. In Proof of Work consensus, these block times need to be very large \(~10 minutes\) to minimize the odds of multiple fullnodes producing a new valid block at the same time. There's no such constraint in Proof of Stake consensus, but without reliable timestamps, a fullnode cannot determine the order of incoming blocks. The popular workaround is to tag each block with a [wallclock timestamp](https://en.bitcoin.it/wiki/Block_timestamp). Because of clock drift and variance in network latencies, the timestamp is only accurate within an hour or two. To workaround the workaround, these systems lengthen block times to provide reasonable certainty that the median timestamp on each block is always increasing. + +Solana takes a very different approach, which it calls _Proof of History_ or _PoH_. Leader nodes "timestamp" blocks with cryptographic proofs that some duration of time has passed since the last proof. All data hashed into the proof most certainly have occurred before the proof was generated. The node then shares the new block with validator nodes, which are able to verify those proofs. The blocks can arrive at validators in any order or even could be replayed years later. With such reliable synchronization guarantees, Solana is able to break blocks into smaller batches of transactions called _entries_. Entries are streamed to validators in realtime, before any notion of block consensus. + +Solana technically never sends a _block_, but uses the term to describe the sequence of entries that fullnodes vote on to achieve _confirmation_. In that way, Solana's confirmation times can be compared apples to apples to block-based systems. The current implementation sets block time to 800ms. + +What's happening under the hood is that entries are streamed to validators as quickly as a leader node can batch a set of valid transactions into an entry. Validators process those entries long before it is time to vote on their validity. By processing the transactions optimistically, there is effectively no delay between the time the last entry is received and the time when the node can vote. In the event consensus is **not** achieved, a node simply rolls back its state. This optimisic processing technique was introduced in 1981 and called [Optimistic Concurrency Control](http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.65.4735). It can be applied to blockchain architecture where a cluster votes on a hash that represents the full ledger up to some _block height_. In Solana, it is implemented trivially using the last entry's PoH hash. + +## Relationship to VDFs + +The Proof of History technique was first described for use in blockchain by Solana in November of 2017. In June of the following year, a similar technique was described at Stanford and called a [verifiable delay function](https://eprint.iacr.org/2018/601.pdf) or _VDF_. + +A desirable property of a VDF is that verification time is very fast. Solana's approach to verifying its delay function is proportional to the time it took to create it. Split over a 4000 core GPU, it is sufficiently fast for Solana's needs, but if you asked the authors of the paper cited above, they might tell you \([and have](https://github.com/solana-labs/solana/issues/388)\) that Solana's approach is algorithmically slow and it shouldn't be called a VDF. We argue the term VDF should represent the category of verifiable delay functions and not just the subset with certain performance characteristics. Until that's resolved, Solana will likely continue using the term PoH for its application-specific VDF. + +Another difference between PoH and VDFs is that a VDF is used only for tracking duration. PoH's hash chain, on the other hand, includes hashes of any data the application observed. That data is a double-edged sword. On one side, the data "proves history" - that the data most certainly existed before hashes after it. On the side, it means the application can manipulate the hash chain by changing _when_ the data is hashed. The PoH chain therefore does not serve as a good source of randomness whereas a VDF without that data could. Solana's [leader rotation algorithm](synchronization.md#leader-rotation), for example, is derived only from the VDF _height_ and not its hash at that height. + +## Relationship to Consensus Mechanisms + +Proof of History is not a consensus mechanism, but it is used to improve the performance of Solana's Proof of Stake consensus. It is also used to improve the performance of the data plane and replication protocols. + +## More on Proof of History + +* [water clock analogy](https://medium.com/solana-labs/proof-of-history-explained-by-a-water-clock-e682183417b8) +* [Proof of History overview](https://medium.com/solana-labs/proof-of-history-a-clock-for-blockchain-cf47a61a9274) + diff --git a/book/src/cluster/turbine-block-propagation.md b/book/src/cluster/turbine-block-propagation.md new file mode 100644 index 0000000000..3a90b5d742 --- /dev/null +++ b/book/src/cluster/turbine-block-propagation.md @@ -0,0 +1,44 @@ +# Turbine Block Propagation + +A Solana cluster uses a multi-layer block propagation mechanism called _Turbine_ to broadcast transaction blobs to all nodes with minimal amount of duplicate messages. The cluster divides itself into small collections of nodes, called _neighborhoods_. Each node is responsible for sharing any data it receives with the other nodes in its neighborhood, as well as propagating the data on to a small set of nodes in other neighborhoods. This way each node only has to communicate with a small number of nodes. + +During its slot, the leader node distributes blobs between the validator nodes in the first neighborhood \(layer 0\). Each validator shares its data within its neighborhood, but also retransmits the blobs to one node in some neighborhoods in the next layer \(layer 1\). The layer-1 nodes each share their data with their neighborhood peers, and retransmit to nodes in the next layer, etc, until all nodes in the cluster have received all the blobs. + +## Neighborhood Assignment - Weighted Selection + +In order for data plane fanout to work, the entire cluster must agree on how the cluster is divided into neighborhoods. To achieve this, all the recognized validator nodes \(the TVU peers\) are sorted by stake and stored in a list. This list is then indexed in different ways to figure out neighborhood boundaries and retransmit peers. For example, the leader will simply select the first nodes to make up layer 0. These will automatically be the highest stake holders, allowing the heaviest votes to come back to the leader first. Layer-0 and lower-layer nodes use the same logic to find their neighbors and next layer peers. + +To reduce the possibility of attack vectors, each blob is transmitted over a random tree of neighborhoods. Each node uses the same set of nodes representing the cluster. A random tree is generated from the set for each blob using randomness derived from the blob itself. Since the random seed is not known in advance, attacks that try to eclipse neighborhoods from certain leaders or blocks become very difficult, and should require almost complete control of the stake in the cluster. + +## Layer and Neighborhood Structure + +The current leader makes its initial broadcasts to at most `DATA_PLANE_FANOUT` nodes. If this layer 0 is smaller than the number of nodes in the cluster, then the data plane fanout mechanism adds layers below. Subsequent layers follow these constraints to determine layer-capacity: Each neighborhood contains `DATA_PLANE_FANOUT` nodes. Layer-0 starts with 1 neighborhood with fanout nodes. The number of nodes in each additional layer grows by a factor of fanout. + +As mentioned above, each node in a layer only has to broadcast its blobs to its neighbors and to exactly 1 node in some next-layer neighborhoods, instead of to every TVU peer in the cluster. A good way to think about this is, layer-0 starts with 1 neighborhood with fanout nodes, layer-1 adds "fanout" neighborhoods, each with fanout nodes and layer-2 will have `fanout * number of nodes in layer-1` and so on. + +This way each node only has to communicate with a maximum of `2 * DATA_PLANE_FANOUT - 1` nodes. + +The following diagram shows how the Leader sends blobs with a Fanout of 2 to Neighborhood 0 in Layer 0 and how the nodes in Neighborhood 0 share their data with each other. + +![Leader sends blobs to Neighborhood 0 in Layer 0](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/data-plane-seeding.svg) + +The following diagram shows how Neighborhood 0 fans out to Neighborhoods 1 and 2. + +![Neighborhood 0 Fanout to Neighborhood 1 and 2](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/data-plane-fanout.svg) + +Finally, the following diagram shows a two layer cluster with a Fanout of 2. + +![Two layer cluster with a Fanout of 2](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/data-plane.svg) + +### Configuration Values + +`DATA_PLANE_FANOUT` - Determines the size of layer 0. Subsequent layers grow by a factor of `DATA_PLANE_FANOUT`. The number of nodes in a neighborhood is equal to the fanout value. Neighborhoods will fill to capacity before new ones are added, i.e if a neighborhood isn't full, it _must_ be the last one. + +Currently, configuration is set when the cluster is launched. In the future, these parameters may be hosted on-chain, allowing modification on the fly as the cluster sizes change. + +## Neighborhoods + +The following diagram shows how two neighborhoods in different layers interact. To cripple a neighborhood, enough nodes \(erasure codes +1\) from the neighborhood above need to fail. Since each neighborhood receives blobs from multiple nodes in a neighborhood in the upper layer, we'd need a big network failure in the upper layers to end up with incomplete data. + +![Inner workings of a neighborhood](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/data-plane-neighborhood.svg) + diff --git a/book/src/cluster/vote-signing.md b/book/src/cluster/vote-signing.md new file mode 100644 index 0000000000..6cea8d36b4 --- /dev/null +++ b/book/src/cluster/vote-signing.md @@ -0,0 +1,67 @@ +# Secure Vote Signing + +A validator fullnode receives entries from the current leader and submits votes confirming those entries are valid. This vote submission presents a security challenge, because forged votes that violate consensus rules could be used to slash the validator's stake. + +The validator votes on its chosen fork by submitting a transaction that uses an asymmetric key to sign the result of its validation work. Other entities can verify this signature using the validator's public key. If the validator's key is used to sign incorrect data \(e.g. votes on multiple forks of the ledger\), the node's stake or its resources could be compromised. + +Solana addresses this risk by splitting off a separate _vote signer_ service that evaluates each vote to ensure it does not violate a slashing condition. + +## Validators, Vote Signers, and Stakeholders + +When a validator receives multiple blocks for the same slot, it tracks all possible forks until it can determine a "best" one. A validator selects the best fork by submitting a vote to it, using a vote signer to minimize the possibility of its vote inadvertently violating a consensus rule and getting a stake slashed. + +A vote signer evaluates the vote proposed by the validator and signs the vote only if it does not violate a slashing condition. A vote signer only needs to maintain minimal state regarding the votes it signed and the votes signed by the rest of the cluster. It doesn't need to process a full set of transactions. + +A stakeholder is an identity that has control of the staked capital. The stakeholder can delegate its stake to the vote signer. Once a stake is delegated, the vote signer votes represent the voting weight of all the delegated stakes, and produce rewards for all the delegated stakes. + +Currently, there is a 1:1 relationship between validators and vote signers, and stakeholders delegate their entire stake to a single vote signer. + +## Signing service + +The vote signing service consists of a JSON RPC server and a request processor. At startup, the service starts the RPC server at a configured port and waits for validator requests. It expects the following type of requests: 1. Register a new validator node + +* The request must contain validator's identity \(public key\) +* The request must be signed with the validator's private key +* The service drops the request if signature of the request cannot be + + verified + +* The service creates a new voting asymmetric key for the validator, and + + returns the public key as a response + +* If a validator tries to register again, the service returns the public key + + from the pre-existing keypair + + 1. Sign a vote + +* The request must contain a voting transaction and all verification data +* The request must be signed with the validator's private key +* The service drops the request if signature of the request cannot be + + verified + +* The service verifies the voting data +* The service returns a signature for the transaction + +## Validator voting + +A validator node, at startup, creates a new vote account and registers it with the cluster by submitting a new "vote register" transaction. The other nodes on the cluster process this transaction and include the new validator in the active set. Subsequently, the validator submits a "new vote" transaction signed with the validator's voting private key on each voting event. + +### Configuration + +The validator node is configured with the signing service's network endpoint \(IP/Port\). + +### Registration + +At startup, the validator registers itself with its signing service using JSON RPC. The RPC call returns the voting public key for the validator node. The validator creates a new "vote register" transaction including this public key, and submits it to the cluster. + +### Vote Collection + +The validator looks up the votes submitted by all the nodes in the cluster for the last voting period. This information is submitted to the signing service with a new vote signing request. + +### New Vote Signing + +The validator creates a "new vote" transaction and sends it to the signing service using JSON RPC. The RPC request also includes the vote verification data. On success, the RPC call returns the signature for the vote. On failure, RPC call returns the failure code. + diff --git a/book/src/getting-started/README.md b/book/src/getting-started/README.md new file mode 100644 index 0000000000..ddd7315571 --- /dev/null +++ b/book/src/getting-started/README.md @@ -0,0 +1,132 @@ +# Getting Started + +The Solana git repository contains all the scripts you might need to spin up your own local testnet. Depending on what you're looking to achieve, you may want to run a different variation, as the full-fledged, performance-enhanced multinode testnet is considerably more complex to set up than a Rust-only, singlenode testnode. If you are looking to develop high-level features, such as experimenting with smart contracts, save yourself some setup headaches and stick to the Rust-only singlenode demo. If you're doing performance optimization of the transaction pipeline, consider the enhanced singlenode demo. If you're doing consensus work, you'll need at least a Rust-only multinode demo. If you want to reproduce our TPS metrics, run the enhanced multinode demo. + +For all four variations, you'd need the latest Rust toolchain and the Solana source code: + +First, install Rust's package manager Cargo. + +```bash +$ curl https://sh.rustup.rs -sSf | sh +$ source $HOME/.cargo/env +``` + +Now checkout the code from github: + +```bash +$ git clone https://github.com/solana-labs/solana.git +$ cd solana +``` + +The demo code is sometimes broken between releases as we add new low-level features, so if this is your first time running the demo, you'll improve your odds of success if you check out the [latest release](https://github.com/solana-labs/solana/releases) before proceeding: + +```bash +$ TAG=$(git describe --tags $(git rev-list --tags --max-count=1)) +$ git checkout $TAG +``` + +### Configuration Setup + +Ensure important programs such as the vote program are built before any nodes are started + +```bash +$ cargo build --all +``` + +The network is initialized with a genesis ledger generated by running the following script. + +```bash +$ ./multinode-demo/setup.sh +``` + +### Drone + +In order for the fullnodes and clients to work, we'll need to spin up a drone to give out some test tokens. The drone delivers Milton Friedman-style "air drops" \(free tokens to requesting clients\) to be used in test transactions. + +Start the drone with: + +```bash +$ ./multinode-demo/drone.sh +``` + +### Singlenode Testnet + +Before you start a validator, make sure you know the IP address of the machine you want to be the bootstrap leader for the demo, and make sure that udp ports 8000-10000 are open on all the machines you want to test with. + +Now start the bootstrap leader in a separate shell: + +```bash +$ ./multinode-demo/bootstrap-leader.sh +``` + +Wait a few seconds for the server to initialize. It will print "leader ready..." when it's ready to receive transactions. The leader will request some tokens from the drone if it doesn't have any. The drone does not need to be running for subsequent leader starts. + +### Multinode Testnet + +To run a multinode testnet, after starting a leader node, spin up some additional validators in separate shells: + +```bash +$ ./multinode-demo/validator-x.sh +``` + +To run a performance-enhanced full node on Linux, [CUDA 10.0](https://developer.nvidia.com/cuda-downloads) must be installed on your system: + +```bash +$ ./fetch-perf-libs.sh +$ SOLANA_CUDA=1 ./multinode-demo/bootstrap-leader.sh +$ SOLANA_CUDA=1 ./multinode-demo/validator.sh +``` + +### Testnet Client Demo + +Now that your singlenode or multinode testnet is up and running let's send it some transactions! + +In a separate shell start the client: + +```bash +$ ./multinode-demo/client.sh # runs against localhost by default +``` + +What just happened? The client demo spins up several threads to send 500,000 transactions to the testnet as quickly as it can. The client then pings the testnet periodically to see how many transactions it processed in that time. Take note that the demo intentionally floods the network with UDP packets, such that the network will almost certainly drop a bunch of them. This ensures the testnet has an opportunity to reach 710k TPS. The client demo completes after it has convinced itself the testnet won't process any additional transactions. You should see several TPS measurements printed to the screen. In the multinode variation, you'll see TPS measurements for each validator node as well. + +### Testnet Debugging + +There are some useful debug messages in the code, you can enable them on a per-module and per-level basis. Before running a leader or validator set the normal RUST\_LOG environment variable. + +For example + +* To enable `info` everywhere and `debug` only in the solana::banking\_stage module: + + ```bash + $ export RUST_LOG=solana=info,solana::banking_stage=debug + ``` + +* To enable BPF program logging: + + ```bash + $ export RUST_LOG=solana_bpf_loader=trace + ``` + +Generally we are using `debug` for infrequent debug messages, `trace` for potentially frequent messages and `info` for performance-related logging. + +You can also attach to a running process with GDB. The leader's process is named _solana-validator_: + +```bash +$ sudo gdb +attach +set logging on +thread apply all bt +``` + +This will dump all the threads stack traces into gdb.txt + +## Public Testnet + +In this example the client connects to our public testnet. To run validators on the testnet you would need to open udp ports `8000-10000`. + +```bash +$ ./multinode-demo/client.sh --entrypoint testnet.solana.com:8001 --drone testnet.solana.com:9900 --duration 60 --tx_count 50 +``` + +You can observe the effects of your client's transactions on our [dashboard](https://metrics.solana.com:3000/d/testnet/testnet-hud?orgId=2&from=now-30m&to=now&refresh=5s&var-testnet=testnet) + diff --git a/book/src/getting-started/testnet-participation.md b/book/src/getting-started/testnet-participation.md new file mode 100644 index 0000000000..64c54a9efc --- /dev/null +++ b/book/src/getting-started/testnet-participation.md @@ -0,0 +1,7 @@ +# Testnet Participation + +Participate in our testnet: + +* [Running a Validator](../running-validator/) +* [Running a Replicator](../running-replicator.md) + diff --git a/book/src/getting-started/webwallet.md b/book/src/getting-started/webwallet.md new file mode 100644 index 0000000000..953a6dac3a --- /dev/null +++ b/book/src/getting-started/webwallet.md @@ -0,0 +1,16 @@ +# Example Client: Web Wallet + +## Build and run a web wallet locally + +First fetch the example code: + +```bash +$ git clone https://github.com/solana-labs/example-webwallet.git +$ cd example-webwallet +$ TAG=$(git describe --tags $(git rev-list --tags +--max-count=1)) +$ git checkout $TAG +``` + +Next, follow the steps in the git repository's [README](https://github.com/solana-labs/example-webwallet/blob/master/README.md). + diff --git a/book/src/implemented-proposals/README.md b/book/src/implemented-proposals/README.md new file mode 100644 index 0000000000..f47169fea0 --- /dev/null +++ b/book/src/implemented-proposals/README.md @@ -0,0 +1,4 @@ +# Implemented Design Proposals + +The following design proposals are fully implemented. + diff --git a/book/src/implemented-proposals/blocktree.md b/book/src/implemented-proposals/blocktree.md new file mode 100644 index 0000000000..302c883b35 --- /dev/null +++ b/book/src/implemented-proposals/blocktree.md @@ -0,0 +1,93 @@ +# Blocktree + +After a block reaches finality, all blocks from that one on down to the genesis block form a linear chain with the familiar name blockchain. Until that point, however, the validator must maintain all potentially valid chains, called _forks_. The process by which forks naturally form as a result of leader rotation is described in [fork generation](../cluster/fork-generation.md). The _blocktree_ data structure described here is how a validator copes with those forks until blocks are finalized. + +The blocktree allows a validator to record every blob it observes on the network, in any order, as long as the blob is signed by the expected leader for a given slot. + +Blobs are moved to a fork-able key space the tuple of `leader slot` + `blob index` \(within the slot\). This permits the skip-list structure of the Solana protocol to be stored in its entirety, without a-priori choosing which fork to follow, which Entries to persist or when to persist them. + +Repair requests for recent blobs are served out of RAM or recent files and out of deeper storage for less recent blobs, as implemented by the store backing Blocktree. + +## Functionalities of Blocktree + +1. Persistence: the Blocktree lives in the front of the nodes verification + + pipeline, right behind network receive and signature verification. If the + + blob received is consistent with the leader schedule \(i.e. was signed by the + + leader for the indicated slot\), it is immediately stored. + +2. Repair: repair is the same as window repair above, but able to serve any + + blob that's been received. Blocktree stores blobs with signatures, + + preserving the chain of origination. + +3. Forks: Blocktree supports random access of blobs, so can support a + + validator's need to rollback and replay from a Bank checkpoint. + +4. Restart: with proper pruning/culling, the Blocktree can be replayed by + + ordered enumeration of entries from slot 0. The logic of the replay stage + + \(i.e. dealing with forks\) will have to be used for the most recent entries in + + the Blocktree. + +## Blocktree Design + +1. Entries in the Blocktree are stored as key-value pairs, where the key is the concatenated slot index and blob index for an entry, and the value is the entry data. Note blob indexes are zero-based for each slot \(i.e. they're slot-relative\). +2. The Blocktree maintains metadata for each slot, in the `SlotMeta` struct containing: + * `slot_index` - The index of this slot + * `num_blocks` - The number of blocks in the slot \(used for chaining to a previous slot\) + * `consumed` - The highest blob index `n`, such that for all `m < n`, there exists a blob in this slot with blob index equal to `n` \(i.e. the highest consecutive blob index\). + * `received` - The highest received blob index for the slot + * `next_slots` - A list of future slots this slot could chain to. Used when rebuilding + + the ledger to find possible fork points. + + * `last_index` - The index of the blob that is flagged as the last blob for this slot. This flag on a blob will be set by the leader for a slot when they are transmitting the last blob for a slot. + * `is_rooted` - True iff every block from 0...slot forms a full sequence without any holes. We can derive is\_rooted for each slot with the following rules. Let slot\(n\) be the slot with index `n`, and slot\(n\).is\_full\(\) is true if the slot with index `n` has all the ticks expected for that slot. Let is\_rooted\(n\) be the statement that "the slot\(n\).is\_rooted is true". Then: + + is\_rooted\(0\) is\_rooted\(n+1\) iff \(is\_rooted\(n\) and slot\(n\).is\_full\(\) +3. Chaining - When a blob for a new slot `x` arrives, we check the number of blocks \(`num_blocks`\) for that new slot \(this information is encoded in the blob\). We then know that this new slot chains to slot `x - num_blocks`. +4. Subscriptions - The Blocktree records a set of slots that have been "subscribed" to. This means entries that chain to these slots will be sent on the Blocktree channel for consumption by the ReplayStage. See the `Blocktree APIs` for details. +5. Update notifications - The Blocktree notifies listeners when slot\(n\).is\_rooted is flipped from false to true for any `n`. + +## Blocktree APIs + +The Blocktree offers a subscription based API that ReplayStage uses to ask for entries it's interested in. The entries will be sent on a channel exposed by the Blocktree. These subscription API's are as follows: 1. `fn get_slots_since(slot_indexes: &[u64]) -> Vec`: Returns new slots connecting to any element of the list `slot_indexes`. + +1. `fn get_slot_entries(slot_index: u64, entry_start_index: usize, max_entries: Option) -> Vec`: Returns the entry vector for the slot starting with `entry_start_index`, capping the result at `max` if `max_entries == Some(max)`, otherwise, no upper limit on the length of the return vector is imposed. + +Note: Cumulatively, this means that the replay stage will now have to know when a slot is finished, and subscribe to the next slot it's interested in to get the next set of entries. Previously, the burden of chaining slots fell on the Blocktree. + +## Interfacing with Bank + +The bank exposes to replay stage: + +1. `prev_hash`: which PoH chain it's working on as indicated by the hash of the last + + entry it processed + +2. `tick_height`: the ticks in the PoH chain currently being verified by this + + bank + +3. `votes`: a stack of records that contain: + 1. `prev_hashes`: what anything after this vote must chain to in PoH + 2. `tick_height`: the tick height at which this vote was cast + 3. `lockout period`: how long a chain must be observed to be in the ledger to + + be able to be chained below this vote + +Replay stage uses Blocktree APIs to find the longest chain of entries it can hang off a previous vote. If that chain of entries does not hang off the latest vote, the replay stage rolls back the bank to that vote and replays the chain from there. + +## Pruning Blocktree + +Once Blocktree entries are old enough, representing all the possible forks becomes less useful, perhaps even problematic for replay upon restart. Once a validator's votes have reached max lockout, however, any Blocktree contents that are not on the PoH chain for that vote for can be pruned, expunged. + +Replicator nodes will be responsible for storing really old ledger contents, and validators need only persist their bank periodically. + diff --git a/book/src/implemented-proposals/credit-only-credit-debit-accounts.md b/book/src/implemented-proposals/credit-only-credit-debit-accounts.md new file mode 100644 index 0000000000..c837fb3db2 --- /dev/null +++ b/book/src/implemented-proposals/credit-only-credit-debit-accounts.md @@ -0,0 +1,105 @@ +# Credit-only Accounts + +This design covers the handling of credit-only and credit-debit accounts in the [runtime](../validator/runtime.md). Accounts already distinguish themselves as credit-only or credit-debit based on the program ID specified by the transaction's instruction. Programs must treat accounts that are not owned by them as credit-only. + +To identify credit-only accounts by program id would require the account to be fetched and loaded from disk. This operation is expensive, and while it is occurring, the runtime would have to reject any transactions referencing the same account. + +The proposal introduces a `num_readonly_accounts` field to the transaction structure, and removes the `program_ids` dedicated vector for program accounts. + +This design doesn't change the runtime transaction processing rules. Programs still can't write or spend accounts that they do not own, but it allows the runtime to optimistically take the correct lock for each account specified in the transaction before loading the accounts from storage. + +Accounts selected as credit-debit by the transaction can still be treated as credit-only by the instructions. + +## Runtime handling + +credit-only accounts have the following properties: + +* Can be deposited into: Deposits can be implemented as a simple `atomic_add`. +* read-only access to account data. + +Instructions that debit or modify the credit-only account data will fail. + +## Account Lock Optimizations + +The Accounts module keeps track of current locked accounts in the runtime, which separates credit-only accounts from the credit-debit accounts. The credit-only accounts can be cached in memory and shared between all the threads executing transactions. + +The current runtime can't predict whether an account is credit-only or credit-debit when the transaction account keys are locked at the start of the transaction processing pipeline. Accounts referenced by the transaction have not been loaded from the disk yet. + +An ideal design would cache the credit-only accounts while they are referenced by any transaction moving through the runtime, and release the cache when the last transaction exits the runtime. + +## Credit-only accounts and read-only account data + +Credit-only account data can be treated as read-only. Credit-debit account data is treated as read-write. + +## Transaction changes + +To enable the possibility of caching accounts only while they are in the runtime, the Transaction structure should be changed in the following way: + +* `program_ids: Vec` - This vector is removed. Program keys can be placed at the end of the `account_keys` vector within the `num_readonly_accounts` number set to the number of programs. +* `num_readonly_accounts: u8` - The number of keys from the **end** of the transaction's `account_keys` array that is credit-only. + +The following possible accounts are present in an transaction: + +* paying account +* RW accounts +* R accounts +* Program IDs + +The paying account must be credit-debit, and program IDs must be credit-only. The first account in the `account_keys` array is always the account that pays for the transaction fee, therefore it cannot be credit-only. For these reasons the credit-only accounts are all grouped together at the end of the `account_keys` vector. Counting credit-only accounts from the end allow for the default `0` value to still be functionally correct, since a transaction will succeed with all credit-debit accounts. + +Since accounts can only appear once in the transaction's `account_keys` array, an account can only be credit-only or credit-debit in a single transaction, not both. The runtime treats a transaction as one atomic unit of execution. If any instruction needs credit-debit access to an account, a copy needs to be made. The write lock is held for the entire time the transaction is being processed by the runtime. + +## Starvation + +Read locks for credit-only accounts can keep the runtime from executing transactions requesting a write lock to a credit-debit account. + +When a request for a write lock is made while a read lock is open, the transaction requesting the write lock should be cached. Upon closing the read lock, the pending transactions can be pushed through the runtime. + +While a pending write transaction exists, any additional read lock requests for that account should fail. It follows that any other write lock requests will also fail. Currently, clients must retransmit when a transaction fails because of a pending transaction. This approach would mimic that behavior as closely as possible while preventing write starvation. + +## Program execution with credit-only accounts + +Before handing off the accounts to program execution, the runtime can mark each account in each instruction as a credit-only account. The credit-only accounts can be passed as references without an extra copy. The transaction will abort on a write to credit-only. + +An alternative is to detect writes to credit-only accounts and fail the transactions before commit. + +## Alternative design + +This design attempts to cache a credit-only account after loading without the use of a transaction-specified credit-only accounts list. Instead, the credit-only accounts are held in a reference-counted table inside the runtime as the transactions are processed. + +1. Transaction accounts are locked. + + a. If the account is present in the ‘credit-only' table, the TX does not fail. + + ```text + The pending state for this TX is marked NeedReadLock. + ``` + +2. Transaction accounts are loaded. + + a. Transaction accounts that are credit-only increase their reference + + ```text + count in the `credit-only` table. + ``` + + b. Transaction accounts that need a write lock and are present in the + + ```text + `credit-only` table fail. + ``` + +3. Transaction accounts are unlocked. + + a. Decrement the `credit-only` lock table reference count; remove if its 0 + + b. Remove from the `lock` set if the account is not in the `credit-only` + + ```text + table. + ``` + +The downside with this approach is that if the `lock` set mutex is released between lock and load to allow better pipelining of transactions, a request for a credit-only account may fail. Therefore, this approach is not suitable for treating programs as credit-only accounts. + +Holding the accounts lock mutex while fetching the account from disk would potentially have a significant performance hit on the runtime. Fetching from disk is expected to be slow, but can be parallelized between multiple disks. + diff --git a/book/src/implemented-proposals/embedding-move.md b/book/src/implemented-proposals/embedding-move.md new file mode 100644 index 0000000000..c948e7dafe --- /dev/null +++ b/book/src/implemented-proposals/embedding-move.md @@ -0,0 +1,36 @@ +# Embedding the Move Langauge + +## Problem + +Solana enables developers to write on-chain programs in general purpose programming languages such as C or Rust, but those programs contain Solana-specific mechanisms. For example, there isn't another chain that asks developers to create a Rust module with a `process_instruction(KeyedAccounts)` function. Whenever practical, Solana should offer dApp developers more portable options. + +Until just recently, no popular blockchain offered a language that could expose the value of Solana's massively parallel [runtime](../validator/runtime.md). Solidity contracts, for example, do not separate references to shared data from contract code, and therefore need to be executed serially to ensure deterministic behavior. In practice we see that the most aggressively optimized EVM-based blockchains all seem to peak out around 1,200 TPS - a small fraction of what Solana can do. The Libra project, on the other hand, designed an on-chain programming language called Move that is more suitable for parallel execution. Like Solana's runtime, Move programs depend on accounts for all shared state. + +The biggest design difference between Solana's runtime and Libra's Move VM is how they manage safe invocations between modules. Solana took an operating systems approach and Libra took the domain-specific language approach. In the runtime, a module must trap back into the runtime to ensure the caller's module did not write to data owned by the callee. Likewise, when the callee completes, it must again trap back to the runtime to ensure the callee did not write to data owned by the caller. Move, on the other hand, includes an advanced type system that allows these checks to be run by its bytecode verifier. Because Move bytecode can be verified, the cost of verification is paid just once, at the time the module is loaded on-chain. In the runtime, the cost is paid each time a transaction crosses between modules. The difference is similar in spirit to the difference between a dynamically-typed language like Python versus a statically-typed language like Java. Solana's runtime allows dApps to be written in general purpose programming languages, but that comes with the cost of runtime checks when jumping between programs. + +This proposal attempts to define a way to embed the Move VM such that: + +* cross-module invocations within Move do not require the runtime's + + cross-program runtime checks + +* Move programs can leverage functionality in other Solana programs and vice + + versa + +* Solana's runtime parallelism is exposed to batches of Move and non-Move + + transactions + +## Proposed Solution + +### Move VM as a Solana loader + +The Move VM shall be embedded as a Solana loader under the identifier `MOVE_PROGRAM_ID`, so that Move modules can be marked as `executable` with the VM as its `owner`. This will allow modules to load module dependencies, as well as allow for parallel execution of Move scripts. + +All data accounts owned by Move modules must set their owners to the loader, `MOVE_PROGRAM_ID`. Since Move modules encapsulate their account data in the same way Solana programs encapsulate theirs, the Move module owner should be embedded in the account data. The runtime will grant write access to the Move VM, and Move grants access to the module accounts. + +### Interacting with Solana programs + +To invoke instructions in non-Move programs, Solana would need to extend the Move VM with a `process_instruction()` system call. It would work the same as `process_instruction()` Rust BPF programs. + diff --git a/book/src/implemented-proposals/installer.md b/book/src/implemented-proposals/installer.md new file mode 100644 index 0000000000..b3e7b0d698 --- /dev/null +++ b/book/src/implemented-proposals/installer.md @@ -0,0 +1,215 @@ +# Cluster Software Installation and Updates + +Currently users are required to build the solana cluster software themselves from the git repository and manually update it, which is error prone and inconvenient. + +This document proposes an easy to use software install and updater that can be used to deploy pre-built binaries for supported platforms. Users may elect to use binaries supplied by Solana or any other party they trust. Deployment of updates is managed using an on-chain update manifest program. + +## Motivating Examples + +### Fetch and run a pre-built installer using a bootstrap curl/shell script + +The easiest install method for supported platforms: + +```bash +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.0/install/solana-install-init.sh | sh +``` + +This script will check github for the latest tagged release and download and run the `solana-install-init` binary from there. + +If additional arguments need to be specified during the installation, the following shell syntax is used: + +```bash +$ init_args=.... # arguments for `solana-install-init ...` +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.0/install/solana-install-init.sh | sh -s - ${init_args} +``` + +### Fetch and run a pre-built installer from a Github release + +With a well-known release URL, a pre-built binary can be obtained for supported platforms: + +```bash +$ curl -o solana-install-init https://github.com/solana-labs/solana/releases/download/v0.18.0/solana-install-init-x86_64-apple-darwin +$ chmod +x ./solana-install-init +$ ./solana-install-init --help +``` + +### Build and run the installer from source + +If a pre-built binary is not available for a given platform, building the installer from source is always an option: + +```bash +$ git clone https://github.com/solana-labs/solana.git +$ cd solana/install +$ cargo run -- --help +``` + +### Deploy a new update to a cluster + +Given a solana release tarball \(as created by `ci/publish-tarball.sh`\) that has already been uploaded to a publicly accessible URL, the following commands will deploy the update: + +```bash +$ solana-keygen new -o update-manifest.json # <-- only generated once, the public key is shared with users +$ solana-install deploy http://example.com/path/to/solana-release.tar.bz2 update-manifest.json +``` + +### Run a validator node that auto updates itself + +```bash +$ solana-install init --pubkey 92DMonmBYXwEMHJ99c9ceRSpAmk9v6i3RdvDdXaVcrfj # <-- pubkey is obtained from whoever is deploying the updates +$ export PATH=~/.local/share/solana-install/bin:$PATH +$ solana-keygen ... # <-- runs the latest solana-keygen +$ solana-install run solana-validator ... # <-- runs a validator, restarting it as necesary when an update is applied +``` + +## On-chain Update Manifest + +An update manifest is used to advertise the deployment of new release tarballs on a solana cluster. The update manifest is stored using the `config` program, and each update manifest account describes a logical update channel for a given target triple \(eg, `x86_64-apple-darwin`\). The account public key is well-known between the entity deploying new updates and users consuming those updates. + +The update tarball itself is hosted elsewhere, off-chain and can be fetched from the specified `download_url`. + +```text +use solana_sdk::signature::Signature; + +/// Information required to download and apply a given update +pub struct UpdateManifest { + pub timestamp_secs: u64, // When the release was deployed in seconds since UNIX EPOCH + pub download_url: String, // Download URL to the release tar.bz2 + pub download_sha256: String, // SHA256 digest of the release tar.bz2 file +} + +/// Userdata of an Update Manifest program Account. +#[derive(Serialize, Deserialize, Default, Debug, PartialEq)] +pub struct SignedUpdateManifest { + pub manifest: UpdateManifest, + pub manifest_signature: Signature, +} +``` + +Note that the `manifest` field itself contains a corresponding signature \(`manifest_signature`\) to guard against man-in-the-middle attacks between the `solana-install` tool and the solana cluster RPC API. + +To guard against rollback attacks, `solana-install` will refuse to install an update with an older `timestamp_secs` than what is currently installed. + +## Release Archive Contents + +A release archive is expected to be a tar file compressed with bzip2 with the following internal structure: + +* `/version.yml` - a simple YAML file containing the field `"target"` - the + + target tuple. Any additional fields are ignored. + +* `/bin/` -- directory containing available programs in the release. + + `solana-install` will symlink this directory to + + `~/.local/share/solana-install/bin` for use by the `PATH` environment + + variable. + +* `...` -- any additional files and directories are permitted + +## solana-install Tool + +The `solana-install` tool is used by the user to install and update their cluster software. + +It manages the following files and directories in the user's home directory: + +* `~/.config/solana/install/config.yml` - user configuration and information about currently installed software version +* `~/.local/share/solana/install/bin` - a symlink to the current release. eg, `~/.local/share/solana-update/-/bin` +* `~/.local/share/solana/install/releases//` - contents of a release + +### Command-line Interface + +```text +solana-install 0.16.0 +The solana cluster software installer + +USAGE: + solana-install [OPTIONS] + +FLAGS: + -h, --help Prints help information + -V, --version Prints version information + +OPTIONS: + -c, --config Configuration file to use [default: .../Library/Preferences/solana/install.yml] + +SUBCOMMANDS: + deploy deploys a new update + help Prints this message or the help of the given subcommand(s) + info displays information about the current installation + init initializes a new installation + run Runs a program while periodically checking and applying software updates + update checks for an update, and if available downloads and applies it +``` + +```text +solana-install-init +initializes a new installation + +USAGE: + solana-install init [OPTIONS] + +FLAGS: + -h, --help Prints help information + +OPTIONS: + -d, --data_dir Directory to store install data [default: .../Library/Application Support/solana] + -u, --url JSON RPC URL for the solana cluster [default: http://testnet.solana.com:8899] + -p, --pubkey Public key of the update manifest [default: 9XX329sPuskWhH4DQh6k16c87dHKhXLBZTL3Gxmve8Gp] +``` + +```text +solana-install-info +displays information about the current installation + +USAGE: + solana-install info [FLAGS] + +FLAGS: + -h, --help Prints help information + -l, --local only display local information, don't check the cluster for new updates +``` + +```text +solana-install-deploy +deploys a new update + +USAGE: + solana-install deploy + +FLAGS: + -h, --help Prints help information + +ARGS: + URL to the solana release archive + Keypair file for the update manifest (/path/to/keypair.json) +``` + +```text +solana-install-update +checks for an update, and if available downloads and applies it + +USAGE: + solana-install update + +FLAGS: + -h, --help Prints help information +``` + +```text +solana-install-run +Runs a program while periodically checking and applying software updates + +USAGE: + solana-install run [program_arguments]... + +FLAGS: + -h, --help Prints help information + +ARGS: + program to run + ... arguments to supply to the program + +The program will be restarted upon a successful software update +``` + diff --git a/book/src/implemented-proposals/leader-leader-transition.md b/book/src/implemented-proposals/leader-leader-transition.md new file mode 100644 index 0000000000..ee84fa3e86 --- /dev/null +++ b/book/src/implemented-proposals/leader-leader-transition.md @@ -0,0 +1,54 @@ +# Leader-to-Leader Transition + +This design describes how leaders transition production of the PoH ledger between each other as each leader generates its own slot. + +## Challenges + +Current leader and the next leader are both racing to generate the final tick for the current slot. The next leader may arrive at that slot while still processing the current leader's entries. + +The ideal scenario would be that the next leader generated its own slot right after it was able to vote for the current leader. It is very likely that the next leader will arrive at their PoH slot height before the current leader finishes broadcasting the entire block. + +The next leader has to make the decision of attaching its own block to the last completed block, or wait to finalize the pending block. It is possible that the next leader will produce a block that proposes that the current leader failed, even though the rest of the network observes that block succeeding. + +The current leader has incentives to start its slot as early as possible to capture economic rewards. Those incentives need to be balanced by the leader's need to attach its block to a block that has the most commitment from the rest of the network. + +## Leader timeout + +While a leader is actively receiving entries for the previous slot, the leader can delay broadcasting the start of its block in real time. The delay is locally configurable by each leader, and can be dynamically based on the previous leader's behavior. If the previous leader's block is confirmed by the leader's TVU before the timeout, the PoH is reset to the start of the slot and this leader produces its block immediately. + +The downsides: + +* Leader delays its own slot, potentially allowing the next leader more time to + + catch up. + +The upsides compared to guards: + +* All the space in a block is used for entries. +* The timeout is not fixed. +* The timeout is local to the leader, and therefore can be clever. The leader's heuristic can take into account turbine performance. +* This design doesn't require a ledger hard fork to update. +* The previous leader can redundantly transmit the last entry in the block to the next leader, and the next leader can speculatively decide to trust it to generate its block without verification of the previous block. +* The leader can speculatively generate the last tick from the last received entry. +* The leader can speculatively process transactions and guess which ones are not going to be encoded by the previous leader. This is also a censorship attack vector. The current leader may withhold transactions that it receives from the clients so it can encode them into its own slot. Once processed, entries can be replayed into PoH quickly. + +## Alternative design options + +### Guard tick at the end of the slot + +A leader does not produce entries in its block after the _penultimate tick_, which is the last tick before the first tick of the next slot. The network votes on the _last tick_, so the time difference between the _penultimate tick_ and the _last tick_ is the forced delay for the entire network, as well as the next leader before a new slot can be generated. The network can produce the _last tick_ from the _penultimate tick_. + +If the next leader receives the _penultimate tick_ before it produces its own _first tick_, it will reset its PoH and produce the _first tick_ from the previous leader's _penultimate tick_. The rest of the network will also reset its PoH to produce the _last tick_ as the id to vote on. + +The downsides: + +* Every vote, and therefore confirmation, is delayed by a fixed timeout. 1 tick, or around 100ms. +* Average case confirmation time for a transaction would be at least 50ms worse. +* It is part of the ledger definition, so to change this behavior would require a hard fork. +* Not all the available space is used for entries. + +The upsides compared to leader timeout: + +* The next leader has received all the previous entries, so it can start processing transactions without recording them into PoH. +* The previous leader can redundantly transmit the last entry containing the _penultimate tick_ to the next leader. The next leader can speculatively generate the _last tick_ as soon as it receives the _penultimate tick_, even before verifying it. + diff --git a/book/src/implemented-proposals/leader-validator-transition.md b/book/src/implemented-proposals/leader-validator-transition.md new file mode 100644 index 0000000000..1afaf51b17 --- /dev/null +++ b/book/src/implemented-proposals/leader-validator-transition.md @@ -0,0 +1,53 @@ +# Leader-to-Validator Transition + +A fullnode typically operates as a validator. If, however, a staker delegates its stake to a fullnode, it will occasionally be selected as a _slot leader_. As a slot leader, the fullnode is responsible for producing blocks during an assigned _slot_. A slot has a duration of some number of preconfigured _ticks_. The duration of those ticks are estimated with a _PoH Recorder_ described later in this document. + +## BankFork + +BankFork tracks changes to the bank state over a specific slot. Once the final tick has been registered the state is frozen. Any attempts to write to are rejected. + +## Validator + +A validator operates on many different concurrent forks of the bank state until it generates a PoH hash with a height within its leader slot. + +## Slot Leader + +A slot leader builds blocks on top of only one fork, the one it last voted on. + +## PoH Recorder + +Slot leaders and validators use a PoH Recorder for both estimating slot height and for recording transactions. + +### PoH Recorder when Validating + +The PoH Recorder acts as a simple VDF when validating. It tells the validator when it needs to switch to the slot leader role. Every time the validator votes on a fork, it should use the fork's latest block id to re-seed the VDF. Re-seeding solves two problems. First, it synchronizes its VDF to the leader's, allowing it to more accurately determine when its leader slot begins. Second, if the previous leader goes down, all wallclock time is accounted for in the next leader's PoH stream. For example, if one block is missing when the leader starts, the block it produces should have a PoH duration of two blocks. The longer duration ensures the following leader isn't attempting to snip all the transactions from the previous leader's slot. + +### PoH Recorder when Leading + +A slot leader use the PoH Recorder to record transactions, locking their positions in time. The PoH hash must be derived from a previous leader's last block. If it isn't, its block will fail PoH verification and be rejected by the cluster. + +The PoH Recorder also serves to inform the slot leader when its slot is over. The leader needs to take care not to modify its bank if recording the transaction would generate a PoH height outside its designated slot. The leader, therefore, should not commit account changes until after it generates the entry's PoH hash. When the PoH height falls outside its slot any transactions in its pipeline may be dropped or forwarded to the next leader. Forwarding is preferred, as it would minimize network congestion, allowing the cluster to advertise higher TPS capacity. + +## Validator Loop + +The PoH Recorder manages the transition between modes. Once a ledger is replayed, the validator can run until the recorder indicates it should be the slot leader. As a slot leader, the node can then execute and record transactions. + +The loop is synchronized to PoH and does a synchronous start and stop of the slot leader functionality. After stopping, the validator's TVU should find itself in the same state as if a different leader had sent it the same block. The following is pseudocode for the loop: + +1. Query the LeaderScheduler for the next assigned slot. +2. Run the TVU over all the forks. + 1. TVU will send votes to what it believes is the "best" fork. + 2. After each vote, restart the PoH Recorder to run until the next assigned + + slot. +3. When time to be a slot leader, start the TPU. Point it to the last fork the + + TVU voted on. + +4. Produce entries until the end of the slot. + 1. For the duration of the slot, the TVU must not vote on other forks. + 2. After the slot ends, the TPU freezes its BankFork. After freezing, + + the TVU may resume voting. +5. Goto 1. + diff --git a/book/src/implemented-proposals/passive-stake-delegation-and-rewards.md b/book/src/implemented-proposals/passive-stake-delegation-and-rewards.md new file mode 100644 index 0000000000..88a0b7c970 --- /dev/null +++ b/book/src/implemented-proposals/passive-stake-delegation-and-rewards.md @@ -0,0 +1,152 @@ +# Passive Stake Delegation and Rewards + +This design proposal focuses on the software architecture for the on-chain voting and staking programs. Incentives for staking is covered in [staking rewards](../proposals/staking-rewards.md). + +The current architecture requires a vote for each delegated stake from the validator, and therefore does not scale to allow replicator clients to automatically delegate their rewards. + +The design proposes a new set of programs for voting and stake delegation, The proposed programs allow many stake accounts to passively earn rewards with a single validator vote without permission or active involvement from the validator. + +## Current Design Problems + +In the current design each staker creates their own VoteState, and assigns a **delegate** in the VoteState that can submit votes. Since the validator has to actively vote for each stake delegated to it, validators can censor stakes by not voting for them. + +The number of votes is equal to the number of stakers, and not the number of validators. Replicator clients are expected to delegate their replication rewards as they are earned, and therefore the number of stakes is expected to be large compared to the number of validators in a long running cluster. + +## Proposed changes to the current design. + +The general idea is that instead of the staker, the validator will own the VoteState program. In this proposal the VoteState program is there to track validator votes, count validator generated credits and to provide any additional validator specific state. The VoteState program is not aware of any stakes delegated to it, and has no staking weight. + +The rewards generated are proportional to the amount of lamports staked. In this proposal stake state is stored as part of the StakeState program. This program is owned by the staker only. Lamports stored in this program are the stake. Unlike the current design, this program contains a new field to indicate which VoteState program the stake is delegated to. + +### VoteState + +VoteState is the current state of all the votes the **delegate** has submitted to the bank. VoteState contains the following state information: + +* votes - The submitted votes data structure. +* credits - The total number of rewards this vote program has generated over its lifetime. +* root\_slot - The last slot to reach the full lockout commitment necessary for rewards. +* commission - The commission taken by this VoteState for any rewards claimed by staker's StakeState accounts. This is the percentage ceiling of the reward. +* Account::lamports - The accumulated lamports from the commission. These do not count as stakes. +* `authorized_vote_signer` - Only this identity is authorized to submit votes, and this field can only modified by this entity + +### VoteInstruction::Initialize + +* `account[0]` - RW - The VoteState + + `VoteState::authorized_vote_signer` is initialized to `account[0]` + + other VoteState members defaulted + +### VoteInstruction::AuthorizeVoteSigner\(Pubkey\) + +* `account[0]` - RW - The VoteState + + `VoteState::authorized_vote_signer` is set to to `Pubkey`, instruction must by + + signed by Pubkey + +### StakeState + +A StakeState takes one of two forms, StakeState::Stake and StakeState::MiningPool. + +### StakeState::Stake + +Stake is the current delegation preference of the **staker**. Stake contains the following state information: + +* `voter_pubkey` - The pubkey of the VoteState instance the lamports are delegated to. +* `credits_observed` - The total credits claimed over the lifetime of the program. +* `stake` - The actual activated stake. +* Account::lamports - Lamports available for staking, including any earned as rewards. + +### StakeState::MiningPool + +There are two approaches to the mining pool. The bank could allow the StakeState program to bypass the token balance check, or a program representing the mining pool could run on the network. To avoid a single network wide lock, the pool can be split into several mining pools. This design focuses on using a StakeState::MiningPool as the cluster wide mining pools. + +* 256 StakeState::MiningPool are initialized, each with 1/256 number of mining pool + + tokens stored as `Account::lamports`. + +The stakes and the MiningPool are accounts that are owned by the same `Stake` program. + +### StakeInstruction::DelegateStake\(stake\) + +* `account[0]` - RW - The StakeState::Stake instance. `StakeState::Stake::credits_observed` is initialized to `VoteState::credits`. `StakeState::Stake::voter_pubkey` is initialized to `account[1]` `StakeState::Stake::stake` is initialized to `stake`, as long as it's less than account\[0\].lamports +* `account[1]` - R - The VoteState instance. + +### StakeInstruction::RedeemVoteCredits + +The VoteState program and the StakeState programs maintain a lifetime counter of total rewards generated and claimed. Therefore an explicit `Clear` instruction is not necessary. When claiming rewards, the total lamports deposited into the StakeState and as validator commission is proportional to `VoteState::credits - StakeState::credits_observed`. + +* `account[0]` - RW - The StakeState::MiningPool instance that will fulfill the + + reward. + +* `account[1]` - RW - The StakeState::Stake instance that is redeeming votes + + credits. + +* `account[2]` - R - The VoteState instance, must be the same as + + `StakeState::voter_pubkey` + +Reward is payed out for the difference between `VoteState::credits` to `StakeState::Delgate.credits_observed`, and `credits_observed` is updated to `VoteState::credits`. The commission is deposited into the `VoteState` token balance, and the reward is deposited to the `StakeState::Stake` token balance. The reward and the commission is weighted by the `StakeState::lamports` divided by total lamports staked. + +The Staker or the owner of the Stake program sends a transaction with this instruction to claim the reward. + +Any random MiningPool can be used to redeem the credits. + +```text +let credits_to_claim = vote_state.credits - stake_state.credits_observed; +stake_state.credits_observed = vote_state.credits; +``` + +`credits_to_claim` is used to compute the reward and commission, and `StakeState::Stake::credits_observed` is updated to the latest `VoteState::credits` value. + +### Collecting network fees into the MiningPool + +At the end of the block, before the bank is frozen, but after it processed all the transactions for the block, a virtual instruction is executed to collect the transaction fees. + +* A portion of the fees are deposited into the leader's account. +* A portion of the fees are deposited into the smallest StakeState::MiningPool + + account. + +### Benefits + +* Single vote for all the stakers. +* Clearing of the credit variable is not necessary for claiming rewards. +* Each delegated stake can claim its rewards independently. +* Commission for the work is deposited when a reward is claimed by the delegated stake. + +This proposal would benefit from the `read-only` accounts proposal to allow for many rewards to be claimed concurrently. + +## Passive Delegation + +Any number of instances of StakeState::Stake programs can delegate to a single VoteState program without an interactive action from the identity controlling the VoteState program or submitting votes to the program. + +The total stake allocated to a VoteState program can be calculated by the sum of all the StakeState programs that have the VoteState pubkey as the `StakeState::Stake::voter_pubkey`. + +## Example Callflow + +![Passive Staking Callflow](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/passive-staking-callflow.svg) + +## Future work + +Validators may want to split the stake delegated to them amongst many validator nodes since stake is used as weight in the network control and data planes. One way to implement this would be for the StakeState to delegate to a pool of validators instead of a single one. + +Instead of a single `vote_pubkey` and `credits_observed` entry in the StakeState program, the program can be initialized with a vector of tuples. + +```text +Voter { + voter_pubkey: Pubkey, + credits_observed: u64, + weight: u8, +} +``` + +* voters: Vec - Array of VoteState accounts that are voting rewards with + + this stake. + +A StakeState program would claim a fraction of the reward from each voter in the `voters` array, and each voter would be delegated a fraction of the stake. + diff --git a/book/src/implemented-proposals/persistent-account-storage.md b/book/src/implemented-proposals/persistent-account-storage.md new file mode 100644 index 0000000000..c09ba7c016 --- /dev/null +++ b/book/src/implemented-proposals/persistent-account-storage.md @@ -0,0 +1,94 @@ +# Persistent Account Storage + +## Persistent Account Storage + +The set of Accounts represent the current computed state of all the transactions that have been processed by a fullnode. Each fullnode needs to maintain this entire set. Each block that is proposed by the network represents a change to this set, and since each block is a potential rollback point the changes need to be reversible. + +Persistent storage like NVMEs are 20 to 40 times cheaper than DDR. The problem with persistent storage is that write and read performance is much slower than DDR and care must be taken in how data is read or written to. Both reads and writes can be split between multiple storage drives and accessed in parallel. This design proposes a data structure that allows for concurrent reads and concurrent writes of storage. Writes are optimized by using an AppendVec data structure, which allows a single writer to append while allowing access to many concurrent readers. The accounts index maintains a pointer to a spot where the account was appended to every fork, thus removing the need for explicit checkpointing of state. + +## AppendVec + +AppendVec is a data structure that allows for random reads concurrent with a single append-only writer. Growing or resizing the capacity of the AppendVec requires exclusive access. This is implemented with an atomic `offset`, which is updated at the end of a completed append. + +The underlying memory for an AppendVec is a memory-mapped file. Memory-mapped files allow for fast random access and paging is handled by the OS. + +## Account Index + +The account index is designed to support a single index for all the currently forked Accounts. + +```text +type AppendVecId = usize; + +type Fork = u64; + +struct AccountMap(Hashmap); + +type AccountIndex = HashMap; +``` + +The index is a map of account Pubkeys to a map of Forks and the location of the Account data in an AppendVec. To get the version of an account for a specific Fork: + +```text +/// Load the account for the pubkey. +/// This function will load the account from the specified fork, falling back to the fork's parents +/// * fork - a virtual Accounts instance, keyed by Fork. Accounts keep track of their parents with Forks, +/// the persistent store +/// * pubkey - The Account's public key. +pub fn load_slow(&self, id: Fork, pubkey: &Pubkey) -> Option<&Account> +``` + +The read is satisfied by pointing to a memory-mapped location in the `AppendVecId` at the stored offset. A reference can be returned without a copy. + +### Root Forks + +[Tower BFT](tower-bft.md) eventually selects a fork as a root fork and the fork is squashed. A squashed/root fork cannot be rolled back. + +When a fork is squashed, all accounts in its parents not already present in the fork are pulled up into the fork by updating the indexes. Accounts with zero balance in the squashed fork are removed from fork by updating the indexes. + +An account can be _garbage-collected_ when squashing makes it unreachable. + +Three possible options exist: + +* Maintain a HashSet of root forks. One is expected to be created every second. The entire tree can be garbage-collected later. Alternatively, if every fork keeps a reference count of accounts, garbage collection could occur any time an index location is updated. +* Remove any pruned forks from the index. Any remaining forks lower in number than the root are can be considered root. +* Scan the index, migrate any old roots into the new one. Any remaining forks lower than the new root can be deleted later. + +## Append-only Writes + +All the updates to Accounts occur as append-only updates. For every account update, a new version is stored in the AppendVec. + +It is possible to optimize updates within a single fork by returning a mutable reference to an already stored account in a fork. The Bank already tracks concurrent access of accounts and guarantees that a write to a specific account fork will not be concurrent with a read to an account at that fork. To support this operation, AppendVec should implement this function: + +```text +fn get_mut(&self, index: u64) -> &mut T; +``` + +This API allows for concurrent mutable access to a memory region at `index`. It relies on the Bank to guarantee exclusive access to that index. + +## Garbage collection + +As accounts get updated, they move to the end of the AppendVec. Once capacity has run out, a new AppendVec can be created and updates can be stored there. Eventually references to an older AppendVec will disappear because all the accounts have been updated, and the old AppendVec can be deleted. + +To speed up this process, it's possible to move Accounts that have not been recently updated to the front of a new AppendVec. This form of garbage collection can be done without requiring exclusive locks to any of the data structures except for the index update. + +The initial implementation for garbage collection is that once all the accounts in an AppendVec become stale versions, it gets reused. The accounts are not updated or moved around once appended. + +## Index Recovery + +Each bank thread has exclusive access to the accounts during append, since the accounts locks cannot be released until the data is committed. But there is no explicit order of writes between the separate AppendVec files. To create an ordering, the index maintains an atomic write version counter. Each append to the AppendVec records the index write version number for that append in the entry for the Account in the AppendVec. + +To recover the index, all the AppendVec files can be read in any order, and the latest write version for every fork should be stored in the index. + +## Snapshots + +To snapshot, the underlying memory-mapped files in the AppendVec need to be flushed to disk. The index can be written out to disk as well. + +## Performance + +* Append-only writes are fast. SSDs and NVMEs, as well as all the OS level kernel data structures, allow for appends to run as fast as PCI or NVMe bandwidth will allow \(2,700 MB/s\). +* Each replay and banking thread writes concurrently to its own AppendVec. +* Each AppendVec could potentially be hosted on a separate NVMe. +* Each replay and banking thread has concurrent read access to all the AppendVecs without blocking writes. +* Index requires an exclusive write lock for writes. Single-thread performance for HashMap updates is on the order of 10m per second. +* Banking and Replay stages should use 32 threads per NVMe. NVMes have optimal performance with 32 concurrent readers or writers. + diff --git a/book/src/implemented-proposals/reliable-vote-transmission.md b/book/src/implemented-proposals/reliable-vote-transmission.md new file mode 100644 index 0000000000..0da6e97437 --- /dev/null +++ b/book/src/implemented-proposals/reliable-vote-transmission.md @@ -0,0 +1,59 @@ +# Reliable Vote Transmission + +Validator votes are messages that have a critical function for consensus and continuous operation of the network. Therefore it is critical that they are reliably delivered and encoded into the ledger. + +## Challenges + +1. Leader rotation is triggered by PoH, which is clock with high drift. So many nodes are likely to have an incorrect view if the next leader is active in realtime or not. +2. The next leader may be easily be flooded. Thus a DDOS would not only prevent delivery of regular transactions, but also consensus messages. +3. UDP is unreliable, and our asynchronous protocol requires any message that is transmitted to be retransmitted until it is observed in the ledger. Retransmittion could potentially cause an unintentional _thundering herd_ against the leader with a large number of validators. Worst case flood would be `(num_nodes * num_retransmits)`. +4. Tracking if the vote has been transmitted or not via the ledger does not guarantee it will appear in a confirmed block. The current observed block may be unrolled. Validators would need to maintain state for each vote and fork. + +## Design + +1. Send votes as a push message through gossip. This ensures delivery of the vote to all the next leaders, not just the next future one. +2. Leaders will read the Crds table for new votes and encode any new received votes into the blocks they propose. This allows for validator votes to be included in rollback forks by all the future leaders. +3. Validators that receive votes in the ledger will add them to their local crds table, not as a push request, but simply add them to the table. This shortcuts the push message protocol, so the validation messages do not need to be retransmitted twice around the network. +4. CrdsValue for vote should look like this `Votes(Vec)` + +Each vote transaction should maintain a `wallclock` in its data. The merge strategy for Votes will keep the last N set of votes as configured by the local client. For push/pull the vector is traversed recursively and each Transaction is treated as an individual CrdsValue with its own local wallclock and signature. + +Gossip is designed for efficient propagation of state. Messages that are sent through gossip-push are batched and propagated with a minimum spanning tree to the rest of the network. Any partial failures in the tree are actively repaired with the gossip-pull protocol while minimizing the amount of data transfered between any nodes. + +## How this design solves the Challenges + +1. Because there is no easy way for validators to be in sync with leaders on the leader's "active" state, gossip allows for eventual delivery regardless of that state. +2. Gossip will deliver the messages to all the subsequent leaders, so if the current leader is flooded the next leader would have already received these votes and is able to encode them. +3. Gossip minimizes the number of requests through the network by maintaining an efficient spanning tree, and using bloom filters to repair state. So retransmit back-off is not necessary and messages are batched. +4. Leaders that read the crds table for votes will encode all the new valid votes that appear in the table. Even if this leader's block is unrolled, the next leader will try to add the same votes without any additional work done by the validator. Thus ensuring not only eventual delivery, but eventual encoding into the ledger. + +## Performance + +1. Worst case propagation time to the next leader is Log\(N\) hops with a base depending on the fanout. With our current default fanout of 6, it is about 6 hops to 20k nodes. +2. The leader should receive 20k validation votes aggregated by gossip-push into 64kb blobs. Which would reduce the number of packets for 20k network to 80 blobs. +3. Each validators votes is replicated across the entire network. To maintain a queue of 5 previous votes the Crds table would grow by 25 megabytes. `(20,000 nodes * 256 bytes * 5)`. + +## Two step implementation rollout + +Initially the network can perform reliably with just 1 vote transmitted and maintained through the network with the current Vote implementation. For small networks a fanout of 6 is sufficient. With small network the memory and push overhead is minor. + +### Sub 1k validator network + +1. Crds just maintains the validators latest vote. +2. Votes are pushed and retransmitted regardless if they are appearing in the ledger. +3. Fanout of 6. +4. Worst case 256kb memory overhead per node. +5. Worst case 4 hops to propagate to every node. +6. Leader should receive the entire validator vote set in 4 push message blobs. + +### Sub 20k network + +Everything above plus the following: + +1. CRDS table maintains a vector of 5 latest validator votes. +2. Votes encode a wallclock. CrdsValue::Votes is a type that recurses into the transaction vector for all the gossip protocols. +3. Increase fanout to 20. +4. Worst case 25mb memory overhead per node. +5. Sub 4 hops worst case to deliver to the entire network. +6. 80 blobs received by the leader for all the validator messages. + diff --git a/book/src/implemented-proposals/repair-service.md b/book/src/implemented-proposals/repair-service.md new file mode 100644 index 0000000000..9f7fd00fef --- /dev/null +++ b/book/src/implemented-proposals/repair-service.md @@ -0,0 +1,49 @@ +# Repair Service + +## Repair Service + +The RepairService is in charge of retrieving missing blobs that failed to be delivered by primary communication protocols like Avalanche. It is in charge of managing the protocols described below in the `Repair Protocols` section below. + +## Challenges: + +1\) Validators can fail to receive particular blobs due to network failures + +2\) Consider a scenario where blocktree contains the set of slots {1, 3, 5}. Then Blocktree receives blobs for some slot 7, where for each of the blobs b, b.parent == 6, so then the parent-child relation 6 -> 7 is stored in blocktree. However, there is no way to chain these slots to any of the existing banks in Blocktree, and thus the `Blob Repair` protocol will not repair these slots. If these slots happen to be part of the main chain, this will halt replay progress on this node. + +3\) Validators that find themselves behind the cluster by an entire epoch struggle/fail to catch up because they do not have a leader schedule for future epochs. If nodes were to blindly accept repair blobs in these future epochs, this exposes nodes to spam. + +## Repair Protocols + +The repair protocol makes best attempts to progress the forking structure of Blocktree. + +The different protocol strategies to address the above challenges: + +1. Blob Repair \(Addresses Challenge \#1\): This is the most basic repair protocol, with the purpose of detecting and filling "holes" in the ledger. Blocktree tracks the latest root slot. RepairService will then periodically iterate every fork in blocktree starting from the root slot, sending repair requests to validators for any missing blobs. It will send at most some `N` repair reqeusts per iteration. + + Note: Validators will only accept blobs within the current verifiable epoch \(epoch the validator has a leader schedule for\). + +2. Preemptive Slot Repair \(Addresses Challenge \#2\): The goal of this protocol is to discover the chaining relationship of "orphan" slots that do not currently chain to any known fork. + * Blocktree will track the set of "orphan" slots in a separate column family. + * RepairService will periodically make `RequestOrphan` requests for each of the orphans in blocktree. + + `RequestOrphan(orphan)` request - `orphan` is the orphan slot that the requestor wants to know the parents of `RequestOrphan(orphan)` response - The highest blobs for each of the first `N` parents of the requested `orphan` + + On receiving the responses `p`, where `p` is some blob in a parent slot, validators will: + + * Insert an empty `SlotMeta` in blocktree for `p.slot` if it doesn't already exist. + * If `p.slot` does exist, update the parent of `p` based on `parents` + + Note: that once these empty slots are added to blocktree, the `Blob Repair` protocol should attempt to fill those slots. + + Note: Validators will only accept responses containing blobs within the current verifiable epoch \(epoch the validator has a leader schedule for\). +3. Repairmen \(Addresses Challenge \#3\): This part of the repair protocol is the primary mechanism by which new nodes joining the cluster catch up after loading a snapshot. This protocol works in a "forward" fashion, so validators can verify every blob that they receive against a known leader schedule. + + Each validator advertises in gossip: + + * Current root + * The set of all completed slots in the confirmed epochs \(an epoch that was calculated based on a bank <= current root\) past the current root + + Observers of this gossip message with higher epochs \(repairmen\) send blobs to catch the lagging node up with the rest of the cluster. The repairmen are responsible for sending the slots within the epochs that are confrimed by the advertised `root` in gossip. The repairmen divide the responsibility of sending each of the missing slots in these epochs based on a random seed \(simple blob.index iteration by N, seeded with the repairman's node\_pubkey\). Ideally, each repairman in an N node cluster \(N nodes whose epochs are higher than that of the repairee\) sends 1/N of the missing blobs. Both data and coding blobs for missing slots are sent. Repairmen do not send blobs again to the same validator until they see the message in gossip updated, at which point they perform another iteration of this protocol. + + Gossip messages are updated every time a validator receives a complete slot within the epoch. Completed slots are detected by blocktree and sent over a channel to RepairService. It is important to note that we know that by the time a slot X is complete, the epoch schedule must exist for the epoch that contains slot X because WindowService will reject blobs for unconfirmed epochs. When a newly completed slot is detected, we also update the current root if it has changed since the last update. The root is made available to RepairService through Blocktree, which holds the latest root. + diff --git a/book/src/implemented-proposals/testing-programs.md b/book/src/implemented-proposals/testing-programs.md new file mode 100644 index 0000000000..9f10008712 --- /dev/null +++ b/book/src/implemented-proposals/testing-programs.md @@ -0,0 +1,52 @@ +# Testing Programs + +Applications send transactions to a Solana cluster and query validators to confirm the transactions were processed and to check each transaction's result. When the cluster doesn't behave as anticipated, it could be for a number of reasons: + +* The program is buggy +* The BPF loader rejected an unsafe program instruction +* The transaction was too big +* The transaction was invalid +* The Runtime tried to execute the transaction when another one was accessing + + the same account + +* The network dropped the transaction +* The cluster rolled back the ledger +* A validator responded to queries maliciously + +## The AsyncClient and SyncClient Traits + +To troubleshoot, the application should retarget a lower-level component, where fewer errors are possible. Retargeting can be done with different implementations of the AsyncClient and SyncClient traits. + +Components implement the following primary methods: + +```text +trait AsyncClient { + fn async_send_transaction(&self, transaction: Transaction) -> io::Result; +} + +trait SyncClient { + fn get_signature_status(&self, signature: &Signature) -> Result>>; +} +``` + +Users send transactions and asynchrounously and synchrounously await results. + +### ThinClient for Clusters + +The highest level implementation, ThinClient, targets a Solana cluster, which may be a deployed testnet or a local cluster running on a development machine. + +### TpuClient for the TPU + +The next level is the TPU implementation, which is not yet implemented. At the TPU level, the application sends transactions over Rust channels, where there can be no surprises from network queues or dropped packets. The TPU implements all "normal" transaction errors. It does signature verification, may report account-in-use errors, and otherwise results in the ledger, complete with proof of history hashes. + +## Low-level testing + +### BankClient for the Bank + +Below the TPU level is the Bank. The Bank doesn't do signature verification or generate a ledger. The Bank is a convenient layer at which to test new on-chain programs. It allows developers to toggle between native program implementations and BPF-compiled variants. No need for the Transact trait here. The Bank's API is synchronous. + +## Unit-testing with the Runtime + +Below the Bank is the Runtime. The Runtime is the ideal test environment for unit-testing. By statically linking the Runtime into a native program implementation, the developer gains the shortest possible edit-compile-run loop. Without any dynamic linking, stack traces include debug symbols and program errors are straightforward to troubleshoot. + diff --git a/book/src/implemented-proposals/tower-bft.md b/book/src/implemented-proposals/tower-bft.md new file mode 100644 index 0000000000..84498f4e3c --- /dev/null +++ b/book/src/implemented-proposals/tower-bft.md @@ -0,0 +1,137 @@ +# Tower BFT + +This design describes Solana's _Tower BFT_ algorithm. It addresses the following problems: + +* Some forks may not end up accepted by the super-majority of the cluster, and voters need to recover from voting on such forks. +* Many forks may be votable by different voters, and each voter may see a different set of votable forks. The selected forks should eventually converge for the cluster. +* Reward based votes have an associated risk. Voters should have the ability to configure how much risk they take on. +* The [cost of rollback](tower-bft.md#cost-of-rollback) needs to be computable. It is important to clients that rely on some measurable form of Consistency. The costs to break consistency need to be computable, and increase super-linearly for older votes. +* ASIC speeds are different between nodes, and attackers could employ Proof of History ASICS that are much faster than the rest of the cluster. Consensus needs to be resistant to attacks that exploit the variability in Proof of History ASIC speed. + +For brevity this design assumes that a single voter with a stake is deployed as an individual validator in the cluster. + +## Time + +The Solana cluster generates a source of time via a Verifiable Delay Function we are calling [Proof of History](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/book/src/synchronization.md). + +Proof of History is used to create a deterministic round robin schedule for all the active leaders. At any given time only 1 leader, which can be computed from the ledger itself, can propose a fork. For more details, see [fork generation](../cluster/fork-generation.md) and [leader rotation](../cluster/leader-rotation.md). + +## Lockouts + +The purpose of the lockout is to force a validator to commit opportunity cost to a specific fork. Lockouts are measured in slots, and therefor represent a real-time forced delay that a validator needs to wait before breaking the commitment to a fork. + +Validators that violate the lockouts and vote for a diverging fork within the lockout should be punished. The proposed punishment is to slash the validator stake if a concurrent vote within a lockout for a non-descendant fork can be proven to the cluster. + +## Algorithm + +The basic idea to this approach is to stack consensus votes and double lockouts. Each vote in the stack is a confirmation of a fork. Each confirmed fork is an ancestor of the fork above it. Each vote has a `lockout` in units of slots before the validator can submit a vote that does not contain the confirmed fork as an ancestor. + +When a vote is added to the stack, the lockouts of all the previous votes in the stack are doubled \(more on this in [Rollback](tower-bft.md#Rollback)\). With each new vote, a validator commits the previous votes to an ever-increasing lockout. At 32 votes we can consider the vote to be at `max lockout` any votes with a lockout equal to or above `1<<32` are dequeued \(FIFO\). Dequeuing a vote is the trigger for a reward. If a vote expires before it is dequeued, it and all the votes above it are popped \(LIFO\) from the vote stack. The validator needs to start rebuilding the stack from that point. + +### Rollback + +Before a vote is pushed to the stack, all the votes leading up to vote with a lower lock time than the new vote are popped. After rollback lockouts are not doubled until the validator catches up to the rollback height of votes. + +For example, a vote stack with the following state: + +| vote | vote time | lockout | lock expiration time | +| ---: | ---: | ---: | ---: | +| 4 | 4 | 2 | 6 | +| 3 | 3 | 4 | 7 | +| 2 | 2 | 8 | 10 | +| 1 | 1 | 16 | 17 | + +_Vote 5_ is at time 9, and the resulting state is + +| vote | vote time | lockout | lock expiration time | +| ---: | ---: | ---: | ---: | +| 5 | 9 | 2 | 11 | +| 2 | 2 | 8 | 10 | +| 1 | 1 | 16 | 17 | + +_Vote 6_ is at time 10 + +| vote | vote time | lockout | lock expiration time | +| ---: | ---: | ---: | ---: | +| 6 | 10 | 2 | 12 | +| 5 | 9 | 4 | 13 | +| 2 | 2 | 8 | 10 | +| 1 | 1 | 16 | 17 | + +At time 10 the new votes caught up to the previous votes. But _vote 2_ expires at 10, so the when _vote 7_ at time 11 is applied the votes including and above _vote 2_ will be popped. + +| vote | vote time | lockout | lock expiration time | +| ---: | ---: | ---: | ---: | +| 7 | 11 | 2 | 13 | +| 1 | 1 | 16 | 17 | + +The lockout for vote 1 will not increase from 16 until the stack contains 5 votes. + +### Slashing and Rewards + +Validators should be rewarded for selecting the fork that the rest of the cluster selected as often as possible. This is well-aligned with generating a reward when the vote stack is full and the oldest vote needs to be dequeued. Thus a reward should be generated for each successful dequeue. + +### Cost of Rollback + +Cost of rollback of _fork A_ is defined as the cost in terms of lockout time to the validator to confirm any other fork that does not include _fork A_ as an ancestor. + +The **Economic Finality** of _fork A_ can be calculated as the loss of all the rewards from rollback of _fork A_ and its descendants, plus the opportunity cost of reward due to the exponentially growing lockout of the votes that have confirmed _fork A_. + +### Thresholds + +Each validator can independently set a threshold of cluster commitment to a fork before that validator commits to a fork. For example, at vote stack index 7, the lockout is 256 time units. A validator may withhold votes and let votes 0-7 expire unless the vote at index 7 has at greater than 50% commitment in the cluster. This allows each validator to independently control how much risk to commit to a fork. Committing to forks at a higher frequency would allow the validator to earn more rewards. + +### Algorithm parameters + +The following parameters need to be tuned: + +* Number of votes in the stack before dequeue occurs \(32\). +* Rate of growth for lockouts in the stack \(2x\). +* Starting default lockout \(2\). +* Threshold depth for minimum cluster commitment before committing to the fork \(8\). +* Minimum cluster commitment size at threshold depth \(50%+\). + +### Free Choice + +A "Free Choice" is an unenforcible validator action. There is no way for the protocol to encode and enforce these actions since each validator can modify the code and adjust the algorithm. A validator that maximizes self-reward over all possible futures should behave in such a way that the system is stable, and the local greedy choice should result in a greedy choice over all possible futures. A set of validator that are engaging in choices to disrupt the protocol should be bound by their stake weight to the denial of service. Two options exits for validator: + +* a validator can outrun previous validator in virtual generation and submit a concurrent fork +* a validator can withhold a vote to observe multiple forks before voting + +In both cases, the validator in the cluster have several forks to pick from concurrently, even though each fork represents a different height. In both cases it is impossible for the protocol to detect if the validator behavior is intentional or not. + +### Greedy Choice for Concurrent Forks + +When evaluating multiple forks, each validator should use the following rules: + +1. Forks must satisfy the _Threshold_ rule. +2. Pick the fork that maximizes the total cluster lockout time for all the ancestor forks. +3. Pick the fork that has the greatest amount of cluster transaction fees. +4. Pick the latest fork in terms of PoH. + +Cluster transaction fees are fees that are deposited to the mining pool as described in the [Staking Rewards](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/book/src/staking-rewards.md) section. + +## PoH ASIC Resistance + +Votes and lockouts grow exponentially while ASIC speed up is linear. There are two possible attack vectors involving a faster ASIC. + +### ASIC censorship + +An attacker generates a concurrent fork that outruns previous leaders in an effort to censor them. A fork proposed by this attacker will be available concurrently with the next available leader. For nodes to pick this fork it must satisfy the _Greedy Choice_ rule. + +1. Fork must have equal number of votes for the ancestor fork. +2. Fork cannot be so far a head as to cause expired votes. +3. Fork must have a greater amount of cluster transaction fees. + +This attack is then limited to censoring the previous leaders fees, and individual transactions. But it cannot halt the cluster, or reduce the validator set compared to the concurrent fork. Fee censorship is limited to access fees going to the leaders but not the validators. + +### ASIC Rollback + +An attacker generates a concurrent fork from an older block to try to rollback the cluster. In this attack the concurrent fork is competing with forks that have already been voted on. This attack is limited by the exponential growth of the lockouts. + +* 1 vote has a lockout of 2 slots. Concurrent fork must be at least 2 slots ahead, and be produced in 1 slot. Therefore requires an ASIC 2x faster. +* 2 votes have a lockout of 4 slots. Concurrent fork must be at least 4 slots ahead and produced in 2 slots. Therefore requires an ASIC 2x faster. +* 3 votes have a lockout of 8 slots. Concurrent fork must be at least 8 slots ahead and produced in 3 slots. Therefore requires an ASIC 2.6x faster. +* 10 votes have a lockout of 1024 slots. 1024/10, or 102.4x faster ASIC. +* 20 votes have a lockout of 2^20 slots. 2^20/20, or 52,428.8x faster ASIC. + diff --git a/book/src/implemented-proposals/transaction-fees.md b/book/src/implemented-proposals/transaction-fees.md new file mode 100644 index 0000000000..a7ad24900c --- /dev/null +++ b/book/src/implemented-proposals/transaction-fees.md @@ -0,0 +1,31 @@ +# Deterministic Transaction Fees + +Transactions currently include a fee field that indicates the maximum fee field a slot leader is permitted to charge to process a transaction. The cluster, on the other hand, agrees on a minimum fee. If the network is congested, the slot leader may prioritize the transactions offering higher fees. That means the client won't know how much was collected until the transaction is confirmed by the cluster and the remaining balance is checked. It smells of exactly what we dislike about Ethereum's "gas", non-determinism. + +## Congestion-driven fees + +Each validator uses _signatures per slot_ \(SPS\) to estimate network congestion and _SPS target_ to estimate the desired processing capacity of the cluster. The validator learns the SPS target from the genesis block, whereas it calculates SPS from recently processed transactions. The genesis block also defines a target `lamports_per_signature`, which is the fee to charge per signature when the cluster is operating at _SPS target_. + +## Calculating fees + +The client uses the JSON RPC API to query the cluster for the current fee parameters. Those parameters are tagged with a blockhash and remain valid until that blockhash is old enough to be rejected by the slot leader. + +Before sending a transaction to the cluster, a client may submit the transaction and fee account data to an SDK module called the _fee calculator_. So long as the client's SDK version matches the slot leader's version, the client is assured that its account will be changed exactly the same number of lamports as returned by the fee calculator. + +## Fee Parameters + +In the first implementation of this design, the only fee parameter is `lamports_per_signature`. The more signatures the cluster needs to verify, the higher the fee. The exact number of lamports is determined by the ratio of SPS to the SPS target. At the end of each slot, the cluster lowers `lamports_per_signature` when SPS is below the target and raises it when above the target. The minimum value for `lamports_per_signature` is 50% of the target `lamports_per_signature` and the maximum value is 10x the target \`lamports\_per\_signature' + +Future parameters might include: + +* `lamports_per_pubkey` - cost to load an account +* `lamports_per_slot_distance` - higher cost to load very old accounts +* `lamports_per_byte` - cost per size of account loaded +* `lamports_per_bpf_instruction` - cost to run a program + +## Attacks + +### Hijacking the SPS Target + +A group of validators can centralize the cluster if they can convince it to raise the SPS Target above a point where the rest of the validators can keep up. Raising the target will cause fees to drop, presumably creating more demand and therefore higher TPS. If the validator doesn't have hardware that can process that many transactions that fast, its confirmation votes will eventually get so long that the cluster will be forced to boot it. + diff --git a/book/src/introduction.md b/book/src/introduction.md index 7d42853330..e1d1265b4a 100644 --- a/book/src/introduction.md +++ b/book/src/introduction.md @@ -1,116 +1,38 @@ -# What is Solana? +# Introduction -Solana is an open source project implementing a new, -high-performance, permissionless blockchain. Solana is also the name of a -company headquartered in San Francisco that maintains the open source project. +## What is Solana? -# About this Book +Solana is an open source project implementing a new, high-performance, permissionless blockchain. Solana is also the name of a company headquartered in San Francisco that maintains the open source project. -This book describes the Solana open source project, a blockchain built from the -ground up for scale. The book covers why Solana is useful, how to use it, how it -works, and why it will continue to work long after the company Solana closes -its doors. The goal of the Solana architecture is to demonstrate there exists a -set of software algorithms that when used in combination to implement a -blockchain, removes software as a performance bottleneck, allowing transaction -throughput to scale proportionally with network bandwidth. The architecture -goes on to satisfy all three desirable properties of a proper blockchain: -it is scalable, secure and decentralized. +## About this Book -The architecture describes a theoretical upper bound of 710 thousand -transactions per second (tps) on a standard gigabit network and 28.4 million -tps on 40 gigabit. Furthermore, the architecture supports safe, concurrent -execution of programs authored in general purpose programming languages such as -C or Rust. +This book describes the Solana open source project, a blockchain built from the ground up for scale. The book covers why Solana is useful, how to use it, how it works, and why it will continue to work long after the company Solana closes its doors. The goal of the Solana architecture is to demonstrate there exists a set of software algorithms that when used in combination to implement a blockchain, removes software as a performance bottleneck, allowing transaction throughput to scale proportionally with network bandwidth. The architecture goes on to satisfy all three desirable properties of a proper blockchain: it is scalable, secure and decentralized. -# Disclaimer +The architecture describes a theoretical upper bound of 710 thousand transactions per second \(tps\) on a standard gigabit network and 28.4 million tps on 40 gigabit. Furthermore, the architecture supports safe, concurrent execution of programs authored in general purpose programming languages such as C or Rust. -All claims, content, designs, algorithms, estimates, roadmaps, specifications, -and performance measurements described in this project are done with the -author's best effort. It is up to the reader to check and validate their -accuracy and truthfulness. Furthermore, nothing in this project constitutes a -solicitation for investment. +## Disclaimer -# History of the Solana Codebase +All claims, content, designs, algorithms, estimates, roadmaps, specifications, and performance measurements described in this project are done with the author's best effort. It is up to the reader to check and validate their accuracy and truthfulness. Furthermore, nothing in this project constitutes a solicitation for investment. -In November of 2017, Anatoly Yakovenko published a whitepaper describing Proof -of History, a technique for keeping time between computers that do not trust -one another. From Anatoly's previous experience designing distributed systems -at Qualcomm, Mesosphere and Dropbox, he knew that a reliable clock makes -network synchronization very simple. When synchronization is simple the -resulting network can be blazing fast, bound only by network bandwidth. +## History of the Solana Codebase -Anatoly watched as blockchain systems without clocks, such as Bitcoin and -Ethereum, struggled to scale beyond 15 transactions per second worldwide when -centralized payment systems such as Visa required peaks of 65,000 tps. Without a -clock, it was clear they'd never graduate to being the global payment system or -global supercomputer most had dreamed them to be. When Anatoly solved the problem of -getting computers that don’t trust each other to agree on time, he knew he had -the key to bring 40 years of distributed systems research to the world of -blockchain. The resulting cluster wouldn't be just 10 times faster, or a 100 -times, or a 1,000 times, but 10,000 times faster, right out of the gate! +In November of 2017, Anatoly Yakovenko published a whitepaper describing Proof of History, a technique for keeping time between computers that do not trust one another. From Anatoly's previous experience designing distributed systems at Qualcomm, Mesosphere and Dropbox, he knew that a reliable clock makes network synchronization very simple. When synchronization is simple the resulting network can be blazing fast, bound only by network bandwidth. -Anatoly's implementation began in a private codebase and was implemented in the -C programming language. Greg Fitzgerald, who had previously worked with Anatoly -at semiconductor giant Qualcomm Incorporated, encouraged him to reimplement the -project in the Rust programming language. Greg had worked on the LLVM compiler -infrastructure, which underlies both the Clang C/C++ compiler as well as the -Rust compiler. Greg claimed that the language's safety guarantees would improve -software productivity and that its lack of a garbage collector would allow -programs to perform as well as those written in C. Anatoly gave it a shot and -just two weeks later, had migrated his entire codebase to Rust. Sold. With -plans to weave all the world's transactions together on a single, scalable -blockchain, Anatoly called the project Loom. +Anatoly watched as blockchain systems without clocks, such as Bitcoin and Ethereum, struggled to scale beyond 15 transactions per second worldwide when centralized payment systems such as Visa required peaks of 65,000 tps. Without a clock, it was clear they'd never graduate to being the global payment system or global supercomputer most had dreamed them to be. When Anatoly solved the problem of getting computers that don’t trust each other to agree on time, he knew he had the key to bring 40 years of distributed systems research to the world of blockchain. The resulting cluster wouldn't be just 10 times faster, or a 100 times, or a 1,000 times, but 10,000 times faster, right out of the gate! -On February 13th of 2018, Greg began prototyping the first open source -implementation of Anatoly's whitepaper. The project was published to GitHub -under the name Silk in the loomprotocol organization. On February 28th, Greg -made his first release, demonstrating 10 thousand signed transactions could be -verified and processed in just over half a second. Shortly after, another -former Qualcomm cohort, Stephen Akridge, demonstrated throughput could be -massively improved by offloading signature verification to graphics processors. -Anatoly recruited Greg, Stephen and three others to co-found a company, then -called Loom. +Anatoly's implementation began in a private codebase and was implemented in the C programming language. Greg Fitzgerald, who had previously worked with Anatoly at semiconductor giant Qualcomm Incorporated, encouraged him to reimplement the project in the Rust programming language. Greg had worked on the LLVM compiler infrastructure, which underlies both the Clang C/C++ compiler as well as the Rust compiler. Greg claimed that the language's safety guarantees would improve software productivity and that its lack of a garbage collector would allow programs to perform as well as those written in C. Anatoly gave it a shot and just two weeks later, had migrated his entire codebase to Rust. Sold. With plans to weave all the world's transactions together on a single, scalable blockchain, Anatoly called the project Loom. -Around the same time, Ethereum-based project Loom Network sprung up and many -people were confused about whether they were the same project. The Loom team decided it -would rebrand. They chose the name Solana, a nod to a small beach town North of -San Diego called Solana Beach, where Anatoly, Greg and Stephen lived and surfed -for three years when they worked for Qualcomm. On March 28th, the team created -the Solana Labs GitHub organization and renamed Greg's prototype Silk to -Solana. +On February 13th of 2018, Greg began prototyping the first open source implementation of Anatoly's whitepaper. The project was published to GitHub under the name Silk in the loomprotocol organization. On February 28th, Greg made his first release, demonstrating 10 thousand signed transactions could be verified and processed in just over half a second. Shortly after, another former Qualcomm cohort, Stephen Akridge, demonstrated throughput could be massively improved by offloading signature verification to graphics processors. Anatoly recruited Greg, Stephen and three others to co-found a company, then called Loom. -In June of 2018, the team scaled up the technology to run on cloud-based -networks and on July 19th, published a 50-node, permissioned, public testnet -consistently supporting bursts of 250,000 transactions per second. In a later release in -December, called v0.10 Pillbox, the team published a permissioned testnet -running 150 nodes on a gigabit network and demonstrated soak tests processing -an *average* of 200 thousand transactions per second with bursts over 500 -thousand. The project was also extended to support on-chain programs written in -the C programming language and run concurrently in a safe execution environment -called BPF. +Around the same time, Ethereum-based project Loom Network sprung up and many people were confused about whether they were the same project. The Loom team decided it would rebrand. They chose the name Solana, a nod to a small beach town North of San Diego called Solana Beach, where Anatoly, Greg and Stephen lived and surfed for three years when they worked for Qualcomm. On March 28th, the team created the Solana Labs GitHub organization and renamed Greg's prototype Silk to Solana. -# What is a Solana Cluster? +In June of 2018, the team scaled up the technology to run on cloud-based networks and on July 19th, published a 50-node, permissioned, public testnet consistently supporting bursts of 250,000 transactions per second. In a later release in December, called v0.10 Pillbox, the team published a permissioned testnet running 150 nodes on a gigabit network and demonstrated soak tests processing an _average_ of 200 thousand transactions per second with bursts over 500 thousand. The project was also extended to support on-chain programs written in the C programming language and run concurrently in a safe execution environment called BPF. -A cluster is a set of computers that work together and can be viewed from the -outside as a single system. A Solana cluster is a set of independently owned -computers working together (and sometimes against each other) to verify the -output of untrusted, user-submitted programs. A Solana cluster can be utilized -any time a user wants to preserve an immutable record of events in time or -programmatic interpretations of those events. One use is to track which of the -computers did meaningful work to keep the cluster running. Another use might be -to track the possession of real-world assets. In each case, the cluster -produces a record of events called the ledger. It will be preserved for the -lifetime of the cluster. As long as someone somewhere in the world maintains a -copy of the ledger, the output of its programs (which may contain a record of -who possesses what) will forever be reproducible, independent of the -organization that launched it. +## What is a Solana Cluster? -# What are Sols? +A cluster is a set of computers that work together and can be viewed from the outside as a single system. A Solana cluster is a set of independently owned computers working together \(and sometimes against each other\) to verify the output of untrusted, user-submitted programs. A Solana cluster can be utilized any time a user wants to preserve an immutable record of events in time or programmatic interpretations of those events. One use is to track which of the computers did meaningful work to keep the cluster running. Another use might be to track the possession of real-world assets. In each case, the cluster produces a record of events called the ledger. It will be preserved for the lifetime of the cluster. As long as someone somewhere in the world maintains a copy of the ledger, the output of its programs \(which may contain a record of who possesses what\) will forever be reproducible, independent of the organization that launched it. + +## What are Sols? + +A sol is the name of Solana's native token, which can be passed to nodes in a Solana cluster in exchange for running an on-chain program or validating its output. The Solana protocol defines that only 1 billion sols will ever exist, but that the system may perform micropayments of fractional sols, and that a sol may be split as many as 34 times. The fractional sol is called a _lamport_. It is named in honor of Solana's biggest technical influence, [Leslie Lamport](https://en.wikipedia.org/wiki/Leslie_Lamport). A lamport has a value of approximately 0.0000000000582 sol \(2^-34\). -A sol is the name of Solana's native token, which can be passed to nodes in a -Solana cluster in exchange for running an on-chain program or validating its -output. The system may perform micropayments of fractional sols and a sol -may be split as many as 34 times. The fractional sol is called a *lamport*. It -is named in honor of Solana's biggest technical influence, [Leslie -Lamport](https://en.wikipedia.org/wiki/Leslie_Lamport). A lamport has a value -of approximately 0.0000000000582 sol (2^-34). diff --git a/book/src/programs/README.md b/book/src/programs/README.md new file mode 100644 index 0000000000..89e8f41539 --- /dev/null +++ b/book/src/programs/README.md @@ -0,0 +1,24 @@ +# Programming Model + +A client _app_ interacts with a Solana cluster by sending it _transactions_ with one or more _instructions_. The Solana _runtime_ passes those instructions to user-contributed _programs_. An instruction might, for example, tell a program to transfer _lamports_ from one _account_ to another or create an interactive contract that governs how lamports are transfered. Instructions are executed atomically. If any instruction is invalid, any changes made within the transaction are discarded. + +## Deploying Programs to a Cluster + +![SDK tools](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/sdk-tools.svg) + +As shown in the diagram above a client creates a program and compiles it to an ELF shared object containing BPF bytecode and sends it to the Solana cluster. The cluster stores the program locally and makes it available to clients via a _program ID_. The program ID is a _public key_ generated by the client and is used to reference the program in subsequent transactions. + +A program may be written in any programming language that can target the Berkley Packet Filter \(BPF\) safe execution environment. The Solana SDK offers the best support for C programs, which is compiled to BPF using the [LLVM compiler infrastructure](https://llvm.org). + +## Storing State between Transactions + +If the program needs to store state between transactions, it does so using _accounts_. Accounts are similar to files in operating systems such as Linux. Like a file, an account may hold arbitrary data and that data persists beyond the lifetime of a program. Also like a file, an account includes metadata that tells the runtime who is allowed to access the data and how. Unlike a file, the account includes metadata for the lifetime of the file. That lifetime is expressed in "tokens", which is a number of fractional native tokens, called _lamports_. Accounts are held in validator memory and pay "rent" to stay there. Each fullnode periodically scan all accounts and collects rent. Any account that drops to zero lamports is purged. + +If an account is marked "executable", it will only be used by a _loader_ to run programs. For example, a BPF-compiled program is marked executable and loaded by the BPF loader. No program is allowed to modify the contents of an executable account. + +An account also includes "owner" metadata. The owner is a program ID. The runtime grants the program write access to the account if its ID matches the owner. If an account is not owned by a program, the program is permitted to read its data and credit the account. + +In the same way that a Linux user uses a path to look up a file, a Solana client uses public keys to look up accounts. To create an account, the client generates a _keypair_ and registers its public key using the CreateAccount instruction. Once registered, transactions reference account keys to grant programs access to accounts. The runtime grants programs read access by default. To grant write access, the client must either assign the account to a program or sign the transaction using the keypair's _secret key_. Since only the holder of the secret key can produce valid signatures matching the account's public key, the runtime recognizes the signature as authorization to modify account data or debit the account. + +After the runtime executes each of the transaction's instructions, it uses the account metadata and transaction signatures to verify that none of the access rules were violated. If a program violates an access rule, the runtime discards all account changes made by all instructions and marks the transaction as failed. + diff --git a/book/src/programs/drones.md b/book/src/programs/drones.md new file mode 100644 index 0000000000..9ed5e97eb1 --- /dev/null +++ b/book/src/programs/drones.md @@ -0,0 +1,42 @@ +# Drones + +This chapter defines an off-chain service called a _drone_, which acts as custodian of a user's private key. In its simplest form, it can be used to create _airdrop_ transactions, a token transfer from the drone's account to a client's account. + +## Signing Service + +A drone is a simple signing service. It listens for requests to sign _transaction data_. Once received, the drone validates the request however it sees fit. It may, for example, only accept transaction data with a `SystemInstruction::Transfer` instruction transferring only up to a certain amount of tokens. If the drone accepts the transaction, it returns an `Ok(Signature)` where `Signature` is a signature of the transaction data using the drone's private key. If it rejects the transaction data, it returns a `DroneError` describing why. + +## Examples + +### Granting access to an on-chain game + +Creator of on-chain game tic-tac-toe hosts a drone that responds to airdrop requests containing an `InitGame` instruction. The drone signs the transaction data in the request and returns it, thereby authorizing its account to pay the transaction fee and as well as seeding the game's account with enough tokens to play it. The user then creates a transaction for its transaction data and the drones signature and submits it to the Solana cluster. Each time the user interacts with the game, the game pays the user enough tokens to pay the next transaction fee to advance the game. At that point, the user may choose to keep the tokens instead of advancing the game. If the creator wants to defend against that case, they could require the user to return to the drone to sign each instruction. + +### Worldwide airdrop of a new token + +Creator of a new on-chain token \(ERC-20 interface\), may wish to do a worldwide airdrop to distribute its tokens to millions of users over just a few seconds. That drone cannot spend resources interacting with the Solana cluster. Instead, the drone should only verify the client is unique and human, and then return the signature. It may also want to listen to the Solana cluster for recent entry IDs to support client retries and to ensure the airdrop is targeting the desired cluster. + +## Attack vectors + +### Invalid recent\_blockhash + +The drone may prefer its airdrops only target a particular Solana cluster. To do that, it listens to the cluster for new entry IDs and ensure any requests reference a recent one. + +Note: to listen for new entry IDs assumes the drone is either a fullnode or a _light_ client. At the time of this writing, light clients have not been implemented and no proposal describes them. This document assumes one of the following approaches be taken: + +1. Define and implement a light client +2. Embed a fullnode +3. Query the jsonrpc API for the latest last id at a rate slightly faster than + + ticks are produced. + +### Double spends + +A client may request multiple airdrops before the first has been submitted to the ledger. The client may do this maliciously or simply because it thinks the first request was dropped. The drone should not simply query the cluster to ensure the client has not already received an airdrop. Instead, it should use `recent_blockhash` to ensure the previous request is expired before signing another. Note that the Solana cluster will reject any transaction with a `recent_blockhash` beyond a certain _age_. + +### Denial of Service + +If the transaction data size is smaller than the size of the returned signature \(or descriptive error\), a single client can flood the network. Considering that a simple `Transfer` operation requires two public keys \(each 32 bytes\) and a `fee` field, and that the returned signature is 64 bytes \(and a byte to indicate `Ok`\), consideration for this attack may not be required. + +In the current design, the drone accepts TCP connections. This allows clients to DoS the service by simply opening lots of idle connections. Switching to UDP may be preferred. The transaction data will be smaller than a UDP packet since the transaction sent to the Solana cluster is already pinned to using UDP. + diff --git a/book/src/programs/tictactoe.md b/book/src/programs/tictactoe.md new file mode 100644 index 0000000000..dd2b4ea41f --- /dev/null +++ b/book/src/programs/tictactoe.md @@ -0,0 +1,22 @@ +# Example: Tic-Tac-Toe + +[Click here to play Tic-Tac-Toe](https://solana-example-tictactoe.herokuapp.com/) on the Solana testnet. Open the link and wait for another player to join, or open the link in a second browser tab to play against yourself. You will see that every move a player makes stores a transaction on the ledger. + +## Build and run Tic-Tac-Toe locally + +First fetch the latest release of the example code: + +```bash +$ git clone https://github.com/solana-labs/example-tictactoe.git +$ cd example-tictactoe +$ TAG=$(git describe --tags $(git rev-list --tags +--max-count=1)) +$ git checkout $TAG +``` + +Next, follow the steps in the git repository's [README](https://github.com/solana-labs/example-tictactoe/blob/master/README.md). + +## Getting lamports to users + +You may have noticed you interacted with the Solana cluster without first needing to acquire lamports to pay transaction fees. Under the hood, the web app creates a new ephemeral identity and sends a request to an off-chain service for a signed transaction authorizing a user to start a new game. The service is called a _drone_. When the app sends the signed transaction to the Solana cluster, the drone's lamports are spent to pay the transaction fee and start the game. In a real world app, the drone might request the user watch an ad or pass a CAPTCHA before signing over its lamports. + diff --git a/book/src/proposals/README.md b/book/src/proposals/README.md new file mode 100644 index 0000000000..ac84a4eb45 --- /dev/null +++ b/book/src/proposals/README.md @@ -0,0 +1,4 @@ +# Accepted Design Proposals + +The following architectural proposals have been accepted by the Solana team, but are not yet fully implemented. The proposals may be implemented as described, implemented differently as issues in the designs become evident, or not implemented at all. If implemented, the descriptions will be moved from this section to earlier chapters in a future version of this book. + diff --git a/book/src/proposals/cluster-test-framework.md b/book/src/proposals/cluster-test-framework.md new file mode 100644 index 0000000000..0422abe959 --- /dev/null +++ b/book/src/proposals/cluster-test-framework.md @@ -0,0 +1,102 @@ +# Cluster Test Framework + +This document proposes the Cluster Test Framework \(CTF\). CTF is a test harness that allows tests to execute against a local, in-process cluster or a deployed cluster. + +## Motivation + +The goal of CTF is to provide a framework for writing tests independent of where and how the cluster is deployed. Regressions can be captured in these tests and the tests can be run against deployed clusters to verify the deployment. The focus of these tests should be on cluster stability, consensus, fault tolerance, API stability. + +Tests should verify a single bug or scenario, and should be written with the least amount of internal plumbing exposed to the test. + +## Design Overview + +Tests are provided an entry point, which is a `contact_info::ContactInfo` structure, and a keypair that has already been funded. + +Each node in the cluster is configured with a `fullnode::ValidatorConfig` at boot time. At boot time this configuration specifies any extra cluster configuration required for the test. The cluster should boot with the configuration when it is run in-process or in a data center. + +Once booted, the test will discover the cluster through a gossip entry point and configure any runtime behaviors via fullnode RPC. + +## Test Interface + +Each CTF test starts with an opaque entry point and a funded keypair. The test should not depend on how the cluster is deployed, and should be able to exercise all the cluster functionality through the publicly available interfaces. + +```text +use crate::contact_info::ContactInfo; +use solana_sdk::signature::{Keypair, KeypairUtil}; +pub fn test_this_behavior( + entry_point_info: &ContactInfo, + funding_keypair: &Keypair, + num_nodes: usize, +) +``` + +## Cluster Discovery + +At test start, the cluster has already been established and is fully connected. The test can discover most of the available nodes over a few second. + +```text +use crate::gossip_service::discover_nodes; + +// Discover the cluster over a few seconds. +let cluster_nodes = discover_nodes(&entry_point_info, num_nodes); +``` + +## Cluster Configuration + +To enable specific scenarios, the cluster needs to be booted with special configurations. These configurations can be captured in `fullnode::ValidatorConfig`. + +For example: + +```text +let mut validator_config = ValidatorConfig::default(); +validator_config.rpc_config.enable_fullnode_exit = true; +let local = LocalCluster::new_with_config( + num_nodes, + 10_000, + 100, + &validator_config + ); +``` + +## How to design a new test + +For example, there is a bug that shows that the cluster fails when it is flooded with invalid advertised gossip nodes. Our gossip library and protocol may change, but the cluster still needs to stay resilient to floods of invalid advertised gossip nodes. + +Configure the RPC service: + +```text +let mut validator_config = ValidatorConfig::default(); +validator_config.rpc_config.enable_rpc_gossip_push = true; +validator_config.rpc_config.enable_rpc_gossip_refresh_active_set = true; +``` + +Wire the RPCs and write a new test: + +```text +pub fn test_large_invalid_gossip_nodes( + entry_point_info: &ContactInfo, + funding_keypair: &Keypair, + num_nodes: usize, +) { + let cluster = discover_nodes(&entry_point_info, num_nodes); + + // Poison the cluster. + let client = create_client(entry_point_info.client_facing_addr(), FULLNODE_PORT_RANGE); + for _ in 0..(num_nodes * 100) { + client.gossip_push( + cluster_info::invalid_contact_info() + ); + } + sleep(Durration::from_millis(1000)); + + // Force refresh of the active set. + for node in &cluster { + let client = create_client(node.client_facing_addr(), FULLNODE_PORT_RANGE); + client.gossip_refresh_active_set(); + } + + // Verify that spends still work. + verify_spends(&cluster); +} +``` + diff --git a/book/src/proposals/cross-program-invocation.md b/book/src/proposals/cross-program-invocation.md new file mode 100644 index 0000000000..64853c78a1 --- /dev/null +++ b/book/src/proposals/cross-program-invocation.md @@ -0,0 +1,71 @@ +# Cross-Program Invocation + +## Problem + +In today's implementation a client can create a transaction that modifies two accounts, each owned by a separate on-chain program: + +```text +let message = Message::new(vec![ + token_instruction::pay(&alice_pubkey), + acme_instruction::launch_missiles(&bob_pubkey), +]); +client.send_message(&[&alice_keypair, &bob_keypair], &message); +``` + +The current implementation does not, however, allow the `acme` program to conveniently invoke `token` instructions on the client's behalf: + +```text +let message = Message::new(vec![ + acme_instruction::pay_and_launch_missiles(&alice_pubkey, &bob_pubkey), +]); +client.send_message(&[&alice_keypair, &bob_keypair], &message); +``` + +Currently, there is no way to create instruction `pay_and_launch_missiles` that executes `token_instruction::pay` from the `acme` program. The workaround is to extend the `acme` program with the implementation of the `token` program, and create `token` accounts with `ACME_PROGRAM_ID`, which the `acme` program is permitted to modify. With that workaround, `acme` can modify token-like accounts created by the `acme` program, but not token accounts created by the `token` program. + +## Proposed Solution + +The goal of this design is to modify Solana's runtime such that an on-chain program can invoke an instruction from another program. + +Given two on-chain programs `token` and `acme`, each implementing instructions `pay()` and `launch_missiles()` respectively, we would ideally like to implement the `acme` module with a call to a function defined in the `token` module: + +```text +use token; + +fn launch_missiles(keyed_accounts: &[KeyedAccount]) -> Result<()> { + ... +} + +fn pay_and_launch_missiles(keyed_accounts: &[KeyedAccount]) -> Result<()> { + token::pay(&keyed_accounts[1..])?; + + launch_missiles(keyed_accounts)?; +} +``` + +The above code would require that the `token` crate be dynamically linked, so that a custom linker could intercept calls and validate accesses to `keyed_accounts`. That is, even though the client intends to modify both `token` and `acme` accounts, only `token` program is permitted to modify the `token` account, and only the `acme` program is permitted to modify the `acme` account. + +Backing off from that ideal cross-program call, a slightly more verbose solution is to expose token's existing `process_instruction()` entrypoint to the acme program: + +```text +use token_instruction; + +fn launch_missiles(keyed_accounts: &[KeyedAccount]) -> Result<()> { + ... +} + +fn pay_and_launch_missiles(keyed_accounts: &[KeyedAccount]) -> Result<()> { + let alice_pubkey = keyed_accounts[1].key; + let instruction = token_instruction::pay(&alice_pubkey); + process_instruction(&instruction)?; + + launch_missiles(keyed_accounts)?; +} +``` + +where `process_instruction()` is built into Solana's runtime and responsible for routing the given instruction to the `token` program via the instruction's `program_id` field. Before invoking `pay()`, the runtime must also ensure that `acme` didn't modify any accounts owned by `token`. It does this by calling `runtime::verify_instruction()` and then afterward updating all the `pre_*` variables to tentatively commit `acme`'s account modifications. After `pay()` completes, the runtime must again ensure that `token` didn't modify any accounts owned by `acme`. It should call `verify_instruction()` again, but this time with the `token` program ID. Lastly, after `pay_and_launch_missiles()` completes, the runtime must call `verify_instruction()` one more time, where it normally would, but using all updated `pre_*` variables. If executing `pay_and_launch_missiles()` up to `pay()` made no invalid account changes, `pay()` made no invalid changes, and executing from `pay()` until `pay_and_launch_missiles()` returns made no invalid changes, then the runtime can transitively assume `pay_and_launch_missiles()` as whole made no invalid account changes, and therefore commit all account modifications. + +### Setting `KeyedAccount.is_signer` + +When `process_instruction()` is invoked, the runtime must create a new `KeyedAccounts` parameter using the signatures from the _original_ transaction data. Since the `token` program is immutable and existed on-chain prior to the `acme` program, the runtime can safely treat the transaction signature as a signature of a transaction with a `token` instruction. When the runtime sees the given instruction references `alice_pubkey`, it looks up the key in the transaction to see if that key corresponds to a transaction signature. In this case it does and so sets `KeyedAccount.is_signer`, thereby authorizing the `token` program to modify Alice's account. + diff --git a/book/src/proposals/ed_overview/README.md b/book/src/proposals/ed_overview/README.md new file mode 100644 index 0000000000..c7860cfba3 --- /dev/null +++ b/book/src/proposals/ed_overview/README.md @@ -0,0 +1,14 @@ +# Cluster Economics + +Solana’s crypto-economic system is designed to promote a healthy, long term self-sustaining economy with participant incentives aligned to the security and decentralization of the network. The main participants in this economy are validation-clients and replication-clients. Their contributions to the network, state validation and data storage respectively, and their requisite remittance mechanisms are discussed below. + +The main channels of participant remittances are referred to as protocol-based rewards and transaction fees. Protocol-based rewards are protocol-derived issuances from a protocol-defined, global inflation rate. These rewards will constitute the total reward delivered to replication clients and a portion of the total rewards for validation clients, the remaining sourced from transaction fees. In the early days of the network, it is likely that protocol-based rewards, deployed based on predefined issuance schedule, will drive the majority of participant incentives to join the network. + +These protocol-based rewards, to be distributed to participating validation and replication clients, are to be a result of a global supply inflation rate, calculated per Solana epoch and distributed amongst the active validator set. As discussed further below, the per annum inflation rate is based on a pre-determined disinflationary schedule. This provides the network with monetary supply predictability which supports long term economic stability and security. + +Transaction fees are market-based participant-to-participant transfers, attached to network interactions as a necessary motivation and compensation for the inclusion and execution of a proposed transaction \(be it a state execution or proof-of-replication verification\). A mechanism for continuous and long-term economic stability through partial burning of each transaction fee is also discussed below. + +A high-level schematic of Solana’s crypto-economic design is shown below in **Figure 1**. The specifics of validation-client economics are described in sections: [Validation-client Economics](ed_validation_client_economics/), [State-validation Protocol-based Rewards](ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md), [State-validation Transaction Fees](ed_validation_client_economics/ed_vce_state_validation_transaction_fees.md) and [Replication-validation Transaction Fees](ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md). Also, the chapter titled [Validation Stake Delegation](ed_validation_client_economics/ed_vce_validation_stake_delegation.md) closes with a discussion of validator delegation opportunties and marketplace. Additionally, in [Storage Rent Economics](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/ed_storage_rend_economics.md), we describe an implementation of storage rent to account for the externality costs of maintaining the active state of the ledger. The [Replication-client Economics](ed_replication_client_economics/) chapter will review the Solana network design for global ledger storage/redundancy and replicator-client economics \([Storage-replication rewards](ed_replication_client_economics/ed_rce_storage_replication_rewards.md)\) along with a replicator-to-validator delegation mechanism designed to aide participant on-boarding into the Solana economy discussed in [Replication-client Reward Auto-delegation](ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md). The [Economic Sustainability](ed_economic_sustainability.md) section dives deeper into Solana’s design for long-term economic sustainability and outlines the constraints and conditions for a self-sustaining economy. An outline of features for an MVP economic design is discussed in the [Economic Design MVP](ed_mvp.md) section. Finally, in chapter [Attack Vectors](ed_attack_vectors.md), various attack vectors will be described and potential vulnerabilities explored and parameterized. + +**Figure 1**: Schematic overview of Solana economic incentive design. + diff --git a/book/src/proposals/ed_overview/ed_attack_vectors.md b/book/src/proposals/ed_overview/ed_attack_vectors.md new file mode 100644 index 0000000000..a917e6b912 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_attack_vectors.md @@ -0,0 +1,12 @@ +# Attack Vectors + +## Colluding validation and replication clients + +A colluding validation-client, may take the strategy to mark PoReps from non-colluding replicator nodes as invalid as an attempt to maximize the rewards for the colluding replicator nodes. In this case, it isn’t feasible for the offended-against replicator nodes to petition the network for resolution as this would result in a network-wide vote on each offending PoRep and create too much overhead for the network to progress adequately. Also, this mitigation attempt would still be vulnerable to a >= 51% staked colluder. + +Alternatively, transaction fees from submitted PoReps are pooled and distributed across validation-clients in proportion to the number of valid PoReps discounted by the number of invalid PoReps as voted by each validator-client. Thus invalid votes are directly dis-incentivized through this reward channel. Invalid votes that are revealed by replicator nodes as fishing PoReps, will not be discounted from the payout PoRep count. + +Another collusion attack involves a validator-client who may take the strategy to ignore invalid PoReps from colluding replicator and vote them as valid. In this case, colluding replicator-clients would not have to store the data while still receiving rewards for validated PoReps. Additionally, colluding validator nodes would also receive rewards for validating these PoReps. To mitigate this attack, validators must randomly sample PoReps corresponding to the ledger block they are validating and because of this, there will be multiple validators that will receive the colluding replicator’s invalid submissions. These non-colluding validators will be incentivized to mark these PoReps as invalid as they have no way to determine whether the proposed invalid PoRep is actually a fishing PoRep, for which a confirmation vote would result in the validator’s stake being slashed. + +In this case, the proportion of time a colluding pair will be successful has an upper limit determined by the % of stake of the network claimed by the colluding validator. This also sets bounds to the value of such an attack. For example, if a colluding validator controls 10% of the total validator stake, transaction fees will be lost \(likely sent to mining pool\) by the colluding replicator 90% of the time and so the attack vector is only profitable if the per-PoRep reward at least 90% higher than the average PoRep transaction fee. While, probabilistically, some colluding replicator-client PoReps will find their way to colluding validation-clients, the network can also monitor rates of paired \(validator + replicator\) discrepancies in voting patterns and censor identified colluders in these cases. + diff --git a/book/src/proposals/ed_overview/ed_economic_sustainability.md b/book/src/proposals/ed_overview/ed_economic_sustainability.md new file mode 100644 index 0000000000..0b6c9ba349 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_economic_sustainability.md @@ -0,0 +1,16 @@ +# Economic Sustainability + +Long term economic sustainability is one of the guiding principles of Solana’s economic design. While it is impossible to predict how decentralized economies will develop over time, especially economies with flexible decentralized governances, we can arrange economic components such that, under certain conditions, a sustainable economy may take shape in the long term. In the case of Solana’s network, these components take the form of the remittances and deposits into and out of the reserve ‘mining pool’. + +The dominant remittances from the Solana mining pool are validator and replicator rewards. The deposit mechanism is a flat, protocol-specified and adjusted, % of each transaction fee. + +The Replicator rewards are to be delivered to replicators from the mining pool after successful PoRep validation. The per-PoRep reward amount is determined as a function of the total network storage redundancy at the time of the PoRep validation and the network goal redundancy. This function is likely to take the form of a discount from a base reward to be delivered when the network has achieved and maintained its goal redundancy. An example of such a reward function is shown in **Figure 3** + +**Figure 3**: Example PoRep reward design as a function of global network storage redundancy. + +In the example shown in Figure 1, multiple per PoRep base rewards are explored \(as a % of Tx Fee\) to be delivered when the global ledger replication redundancy meets 10X. When the global ledger replication redundancy is less than 10X, the base reward is discounted as a function of the square of the ratio of the actual ledger replication redundancy to the goal redundancy \(i.e. 10X\). + +The other protocol-based remittance goes to validation-clients as a reward distributed in proportion to stake-weight for voting to validate the ledger state. The functional issuance of this reward is described in [State-validation Protocol-based Rewards](ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md) and is designed to reduce over time until validators are incentivized solely through collection of transaction fees. Therefore, in the long-run, protocol-based rewards to replication-nodes will be the only remittances from the mining pool, and will have to be countered by the portion of each non-PoRep transaction fee that is directed back into the mining pool. I.e. for a long-term self-sustaining economy, replicator-client rewards must be subsidized through a minimum fee on each non-PoRep transaction pre-allocated to the mining pool. Through this constraint, we can write the following inequality: + +**== WIP** [**here**](https://docs.google.com/document/d/1HBDasdkjS4Ja9wC_tIUsZPVcxGAWTuYOq9zf6xoQNps/edit?usp=sharing) **==** + diff --git a/book/src/proposals/ed_overview/ed_mvp.md b/book/src/proposals/ed_overview/ed_mvp.md new file mode 100644 index 0000000000..56ffd34ffc --- /dev/null +++ b/book/src/proposals/ed_overview/ed_mvp.md @@ -0,0 +1,13 @@ +# Economic Design MVP + +The preceeding sections, outlined in the [Economic Design Overview](./), describe a long-term vision of a sustainable Solana economy. Of course, we don't expect the final implementation to perfectly match what has been described above. We intend to fully engage with network stakeholders throughout the implementation phases \(i.e. pre-testnet, testnet, mainnet\) to ensure the system supports, and is representative of, the various network participants' interests. The first step toward this goal, however, is outlining a some desired MVP economic features to be available for early pre-testnet and testnet participants. Below is a rough sketch outlining basic economic functionality from which a more complete and functional system can be developed. + +## MVP Economic Features + +* Faucet to deliver testnet SOLs to validators for staking and dapp development. +* Mechanism by which validators are rewarded in proportion to their stake. Interest rate mechansism \(i.e. to be determined by total % staked\) to come later. +* Ability to delegate tokens to validator nodes. +* Replicators to receive fixed, arbitrary reward for submitting validated PoReps. Reward size mechanism \(i.e. PoRep reward as a function of total ledger redundancy\) to come later. +* Pooling of replicator PoRep transaction fees and weighted distribution to validators based on PoRep verification \(see [Replication-validation Transaction Fees](ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md). It will be useful to test this protection against attacks on testnet. +* Nice-to-have: auto-delegation of replicator rewards to validator. + diff --git a/book/src/proposals/ed_overview/ed_references.md b/book/src/proposals/ed_overview/ed_references.md new file mode 100644 index 0000000000..41b46a45a1 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_references.md @@ -0,0 +1,6 @@ +# References + +1. [https://blog.ethereum.org/2016/07/27/inflation-transaction-fees-cryptocurrency-monetary-policy/](https://blog.ethereum.org/2016/07/27/inflation-transaction-fees-cryptocurrency-monetary-policy/) +2. [https://medium.com/solana-labs/how-to-create-decentralized-storage-for-a-multi-petabyte-digital-ledger-2499a3a8c281](https://medium.com/solana-labs/how-to-create-decentralized-storage-for-a-multi-petabyte-digital-ledger-2499a3a8c281) +3. [https://medium.com/solana-labs/how-to-create-decentralized-storage-for-a-multi-petabyte-digital-ledger-2499a3a8c281](https://medium.com/solana-labs/how-to-create-decentralized-storage-for-a-multi-petabyte-digital-ledger-2499a3a8c281) + diff --git a/book/src/proposals/ed_overview/ed_replication_client_economics/README.md b/book/src/proposals/ed_overview/ed_replication_client_economics/README.md new file mode 100644 index 0000000000..a9de091252 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_replication_client_economics/README.md @@ -0,0 +1,4 @@ +# Replication-client Economics + +Replication-clients should be rewarded for providing the network with storage space. Incentivization of the set of replicators provides data security through redundancy of the historical ledger. Replication nodes are rewarded in proportion to the amount of ledger data storage provided. These rewards are captured by generating and entering Proofs of Replication \(PoReps\) into the PoH stream which can be validated by Validation nodes as described above in the [Replication-validation Transaction Fees](../ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md) chapter. + diff --git a/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md b/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md new file mode 100644 index 0000000000..519dc28b90 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md @@ -0,0 +1,6 @@ +# Replication-client Reward Auto-delegation + +The ability for Solana network participant’s to earn rewards by providing storage service is a unique on-boarding path that requires little hardware overhead and minimal upfront capital. It offers an avenue for individuals with extra-storage space on their home laptops or PCs to contribute to the security of the network and become integrated into the Solana economy. + +To enhance this on-boarding ramp and facilitate further participation and investment in the Solana economy, replication-clients have the opportunity to auto-delegate their rewards to validation-clients of their choice. Much like the automatic reinvestment of stock dividends, in this scenario, a replicator-client can earn Solana tokens by providing some storage capacity to the network \(i.e. via submitting valid PoReps\), have the protocol-based rewards automatically assigned as delegation to a staked validator node and therefore earning interest in the validation-client reward pool. + diff --git a/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_storage_replication_rewards.md b/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_storage_replication_rewards.md new file mode 100644 index 0000000000..e391722e1c --- /dev/null +++ b/book/src/proposals/ed_overview/ed_replication_client_economics/ed_rce_storage_replication_rewards.md @@ -0,0 +1,6 @@ +# Storage-replication Rewards + +Replicator-clients download, encrypt and submit PoReps for ledger block sections.3 PoReps submitted to the PoH stream, and subsequently validated, function as evidence that the submitting replicator client is indeed storing the assigned ledger block sections on local hard drive space as a service to the network. Therefore, replicator clients should earn protocol rewards proportional to the amount of storage, and the number of successfully validated PoReps, that they are verifiably providing to the network. + +Additionally, replicator clients have the opportunity to capture a portion of slashed bounties \[TBD\] of dishonest validator clients. This can be accomplished by a replicator client submitting a verifiably false PoRep for which a dishonest validator client receives and signs as a valid PoRep. This reward incentive is to prevent lazy validators and minimize validator-replicator collusion attacks, more on this below. + diff --git a/book/src/proposals/ed_overview/ed_validation_client_economics/README.md b/book/src/proposals/ed_overview/ed_validation_client_economics/README.md new file mode 100644 index 0000000000..46a7a98c78 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_validation_client_economics/README.md @@ -0,0 +1,4 @@ +# Validation-client Economics + +Validator-clients are eligible to receive protocol-based \(i.e. via inflation\) rewards issued via stake-based annual interest rates \(calculated per epoch\) by providing compute \(CPU+GPU\) resources to validate and vote on a given PoH state. These protocol-based rewards are determined through an algorithmic disinflationary schedule as a function of total amount of circulating tokens. Additionally, these clients may earn revenue through fees via state-validation transactions and Proof-of-Replication \(PoRep\) transactions. For clarity, we separately describe the design and motivation of these revenue distriubutions for validation-clients below: state-validation protocol-based rewards, state-validation transaction fees and rent, and PoRep-validation transaction fees. + diff --git a/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md new file mode 100644 index 0000000000..0731595b47 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_replication_validation_transaction_fees.md @@ -0,0 +1,10 @@ +# Replication-validation Transaction Fees + +As previously mentioned, validator-clients will also be responsible for validating PoReps submitted into the PoH stream by replicator-clients. In this case, validators are providing compute \(CPU/GPU\) and light storage resources to confirm that these replication proofs could only be generated by a client that is storing the referenced PoH leger block.2 + +While replication-clients are incentivized and rewarded through protocol-based rewards schedule \(see [Replication-client Economics](../ed_replication_client_economics/)\), validator-clients will be incentivized to include and validate PoReps in PoH through collection of transaction fees associated with the submitted PoReps and distribution of protocol rewards proportional to the validated PoReps. As will be described in detail in the Section 3.1, replication-client rewards are protocol-based and designed to reward based on a global data redundancy factor. I.e. the protocol will incentivize replication-client participation through rewards based on a target ledger redundancy \(e.g. 10x data redundancy\). + +The validation of PoReps by validation-clients is computationally more expensive than state-validation \(detail in the [Economic Sustainability](../ed_economic_sustainability.md) chapter\), thus the transaction fees are expected to be proportionally higher. + +There are various attack vectors available for colluding validation and replication clients, as described in detail below in [Economic Sustainability](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/ed_economic_sustainability/README.md). To protect against various collusion attack vectors, for a given epoch, validator rewards are distributed across participating validation-clients in proportion to the number of validated PoReps in the epoch less the number of PoReps that mismatch the replicators challenge. The PoRep challenge game is described in [Ledger Replication](https://github.com/solana-labs/solana/blob/master/book/src/ledger-replication.md#the-porep-game). This design rewards validators proportional to the number of PoReps they process and validate, while providing negative pressure for validation-clients to submit lazy or malicious invalid votes on submitted PoReps \(note that it is computationally prohibitive to determine whether a validator-client has marked a valid PoRep as invalid\). + diff --git a/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md new file mode 100644 index 0000000000..a60111be75 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_protocol_based_rewards.md @@ -0,0 +1,29 @@ +# State-validation Protocol-based Rewards + +Validator-clients have two functional roles in the Solana network: + +* Validate \(vote\) the current global state of that PoH along with any Proofs-of-Replication \(see [Replication Client Economics](../ed_replication_client_economics/)\) that they are eligible to validate. +* Be elected as ‘leader’ on a stake-weighted round-robin schedule during which time they are responsible for collecting outstanding transactions and Proofs-of-Replication and incorporating them into the PoH, thus updating the global state of the network and providing chain continuity. + +Validator-client rewards for these services are to be distributed at the end of each Solana epoch. Compensation for validator-clients is provided via a protocol-based annual inflation rate dispersed in proportion to the stake-weight of each validator \(see below\) along with leader-claimed transaction fees available during each leader rotation. I.e. during the time a given validator-client is elected as leader, it has the opportunity to keep a portion of each transaction fee, less a protocol-specified amount that is destroyed \(see [Validation-client State Transaction Fees](ed_vce_state_validation_transaction_fees.md)\). PoRep transaction fees are also collected by the leader client and validator PoRep rewards are distributed in proportion to the number of validated PoReps less the number of PoReps that mismatch a replicator's challenge. \(see [Replication-client Transaction Fees](ed_vce_replication_validation_transaction_fees.md)\) + +The effective protocol-based annual interest rate \(%\) per epoch to be distributed to validation-clients is to be a function of: + +* the current global inflation rate, derived from the pre-determined dis-inflationary issuance schedule +* the fraction of staked SOLs out of the current total circulating supply, +* the up-time/participation \[% of available slots that validator had opportunity to vote on\] of a given validator over the previous epoch. + +The first factor is a function of protocol parameters only \(i.e. independent of validator behavior in a given epoch\) and results in a global validation reward schedule designed to incentivize early participation, provide clear montetary stability and provide optimal security in the network. + +At any given point in time, a specific validator's interest rate can be determined based on the porportion of circulating supply that is staked by the network and the validator's uptime/activity in the previous epoch. For an illustrative example, consider a hypothetical instance of the network with an initial circulating token supply of 250MM tokens with an additional 250MM vesting over 3 years. Additionally an inflation rate is specified at network launch of 7.5%, and a disinflationary schedule of 20% decrease in inflation rate per year \(the actual rates to be implemented are to be worked out during the testnet experimentation phase of mainnet launch\). With these broad assumptions, the 10-year inflation rate \(adjusted daily for this example\) is shown in **Figure 2**, while the total circulating token supply is illustrated in **Figure 3**. Neglected in this toy-model is the inflation supression due to the portion of each transaction fee that is to be destroyed. + +![drawing](../../../.gitbook/assets/p_ex_schedule.png) \*\*Figure 2:\*\* In this example schedule, the annual inflation rate \[%\] reduces at around 20% per year, until it reaches the long-term, fixed, 1.5% rate. + +![drawing](../../../.gitbook/assets/p_ex_supply%20%283%29.png) \*\*Figure 3:\*\* The total token supply over a 10-year period, based on an initial 250MM tokens with the disinflationary inflation schedule as shown in \*\*Figure 2\*\* Over time, the interest rate, at a fixed network staked percentage, will reduce concordant with network inflation. Validation-client interest rates are designed to be higher in the early days of the network to incentivize participation and jumpstart the network economy. As previously mentioned, the inflation rate is expected to stabalize near 1-2% which also results in a fixed, long-term, interest rate to be provided to validator-clients. This value does not represent the total interest available to validator-clients as transaction fees for both state-validation and ledger storage replication \(PoReps\) are not accounted for here. Given these example parameters, annualized validator-specific interest rates can be determined based on the global fraction of tokens bonded as stake, as well as their uptime/activity in the previous epoch. For the purpose of this example, we assume 100% uptime for all validators and a split in interest-based rewards between validators and replicator nodes of 80%/20%. Additionally, the fraction of staked circulating supply is assummed to be constant. Based on these assumptions, an annualized validation-client interest rate schedule as a function of % circulating token supply that is staked is shown in\*\* Figure 4\*\*. + +![drawing](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/p_ex_interest.png) + +**Figure 4:** Shown here are example validator interest rates over time, neglecting transaction fees, segmented by fraction of total circulating supply bonded as stake. + +This epoch-specific protocol-defined interest rate sets an upper limit of _protocol-generated_ annual interest rate \(not absolute total interest rate\) possible to be delivered to any validator-client per epoch. The distributed interest rate per epoch is then discounted from this value based on the participation of the validator-client during the previous epoch. + diff --git a/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_transaction_fees.md b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_transaction_fees.md new file mode 100644 index 0000000000..9ed0d65145 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_state_validation_transaction_fees.md @@ -0,0 +1,17 @@ +# State-validation Transaction Fees + +Each transaction sent through the network, to be processed by the current leader validation-client and confirmed as a global state transaction, must contain a transaction fee. Transaction fees offer many benefits in the Solana economic design, for example they: + +* provide unit compensation to the validator network for the CPU/GPU resources necessary to process the state transaction, +* reduce network spam by introducing real cost to transactions, +* open avenues for a transaction market to incentivize validation-client to collect and process submitted transactions in their function as leader, +* and provide potential long-term economic stability of the network through a protocol-captured minimum fee amount per transaction, as described below. + +Many current blockchain economies \(e.g. Bitcoin, Ethereum\), rely on protocol-based rewards to support the economy in the short term, with the assumption that the revenue generated through transaction fees will support the economy in the long term, when the protocol derived rewards expire. In an attempt to create a sustainable economy through protocol-based rewards and transaction fees, a fixed portion of each transaction fee is destroyed, with the remaining fee going to the current leader processing the transaction. A scheduled global inflation rate provides a source for rewards distributed to validation-clients, through the process described above, and replication-clients, as discussed below. + +Transaction fees are set by the network cluster based on recent historical throughput, see [Congestion Driven Fees](../../../implemented-proposals/transaction-fees.md#congestion-driven-fees). This minimum portion of each transaction fee can be dynamically adjusted depending on historical gas usage. In this way, the protocol can use the minimum fee to target a desired hardware utilisation. By monitoring a protocol specified gas usage with respect to a desired, target usage amount, the minimum fee can be raised/lowered which should, in turn, lower/raise the actual gas usage per block until it reaches the target amount. This adjustment process can be thought of as similar to the difficulty adjustment algorithm in the Bitcoin protocol, however in this case it is adjusting the minimum transaction fee to guide the transaction processing hardware usage to a desired level. + +As mentioned, a fixed-proportion of each transaction fee is to be destroyed. The intent of this design is to retain leader incentive to include as many transactions as possible within the leader-slot time, while providing an inflation limiting mechansim that protects against "tax evasion" attacks \(i.e. side-channel fee payments\)[1](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/ed_referenced.md). + +Additionally, the burnt fees can be a consideration in fork selection. In the case of a PoH fork with a malicious, censoring leader, we would expect the total fees destroyed to be less than a comparable honest fork, due to the fees lost from censoring. If the censoring leader is to compensate for these lost protocol fees, they would have to replace the burnt fees on their fork themselves, thus potentially reducing the incentive to censor in the first place. + diff --git a/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_validation_stake_delegation.md b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_validation_stake_delegation.md new file mode 100644 index 0000000000..b6c75c1a46 --- /dev/null +++ b/book/src/proposals/ed_overview/ed_validation_client_economics/ed_vce_validation_stake_delegation.md @@ -0,0 +1,30 @@ +# Validation Stake Delegation + +Running a Solana validation-client required relatively modest upfront hardware capital investment. **Table 2** provides an example hardware configuration to support ~1M tx/s with estimated ‘off-the-shelf’ costs: + +| Component | Example | Estimated Cost | +| :--- | :--- | :--- | +| GPU | 2x 2080 Ti | $2500 | +| or | 4x 1080 Ti | $2800 | +| OS/Ledger Storage | Samsung 860 Evo 2TB | $370 | +| Accounts storage | 2x Samsung 970 Pro M.2 512GB | $340 | +| RAM | 32 Gb | $300 | +| Motherboard | AMD x399 | $400 | +| CPU | AMD Threadripper 2920x | $650 | +| Case | | $100 | +| Power supply | EVGA 1600W | $300 | +| Network | > 500 mbps | | +| Network \(1\) | Google webpass business bay area 1gbps unlimited | $5500/mo | +| Network \(2\) | Hurricane Electric bay area colo 1gbps | $500/mo | + +**Table 2** example high-end hardware setup for running a Solana client. + +Despite the low-barrier to entry as a validation-client, from a capital investment perspective, as in any developing economy, there will be much opportunity and need for trusted validation services as evidenced by node reliability, UX/UI, APIs and other software accessibility tools. Additionally, although Solana’s validator node startup costs are nominal when compared to similar networks, they may still be somewhat restrictive for some potential participants. In the spirit of developing a true decentralized, permissionless network, these interested parties still have two options to become involved in the Solana network/economy: + +1. Delegation of previously acquired tokens with a reliable validation node to earn a portion of interest generated +2. Provide local storage space as a replication-client and receive rewards by submitting Proof-of-Replication \(see [Replication-client Economics](../ed_replication_client_economics/)\). + + a. This participant has the additional option to directly delegate their earned storage rewards \([Replication-client Reward Auto-delegation](../ed_replication_client_economics/ed_rce_replication_client_reward_auto_delegation.md)\) + +Delegation of tokens to validation-clients, via option 1, provides a way for passive Solana token holders to become part of the active Solana economy and earn interest rates proportional to the interest rate generated by the delegated validation-client. Additionally, this feature creates a healthy validation-client market, with potential validation-client nodes competing to build reliable, transparent and profitable delegation services. + diff --git a/book/src/proposals/ledger-replication-to-implement.md b/book/src/proposals/ledger-replication-to-implement.md new file mode 100644 index 0000000000..5e4043cd3f --- /dev/null +++ b/book/src/proposals/ledger-replication-to-implement.md @@ -0,0 +1,137 @@ +# Ledger Replication + +Replication behavior yet to be implemented. + +## Storage epoch + +The storage epoch should be the number of slots which results in around 100GB-1TB of ledger to be generated for replicators to store. Replicators will start storing ledger when a given fork has a high probability of not being rolled back. + +## Validator behavior + +1. Every NUM\_KEY\_ROTATION\_TICKS it also validates samples received from + + replicators. It signs the PoH hash at that point and uses the following + + algorithm with the signature as the input: + + * The low 5 bits of the first byte of the signature creates an index into + + another starting byte of the signature. + + * The validator then looks at the set of storage proofs where the byte of + + the proof's sha state vector starting from the low byte matches exactly + + with the chosen byte\(s\) of the signature. + + * If the set of proofs is larger than the validator can handle, then it + + increases to matching 2 bytes in the signature. + + * Validator continues to increase the number of matching bytes until a + + workable set is found. + + * It then creates a mask of valid proofs and fake proofs and sends it to + + the leader. This is a storage proof confirmation transaction. + +2. After a lockout period of NUM\_SECONDS\_STORAGE\_LOCKOUT seconds, the + + validator then submits a storage proof claim transaction which then causes the + + distribution of the storage reward if no challenges were seen for the proof to + + the validators and replicators party to the proofs. + +## Replicator behavior + +1. The replicator then generates another set of offsets which it submits a fake + + proof with an incorrect sha state. It can be proven to be fake by providing the + + seed for the hash result. + + * A fake proof should consist of a replicator hash of a signature of a PoH + + value. That way when the replicator reveals the fake proof, it can be + + verified on chain. + +2. The replicator monitors the ledger, if it sees a fake proof integrated, it + + creates a challenge transaction and submits it to the current leader. The + + transacation proves the validator incorrectly validated a fake storage proof. + + The replicator is rewarded and the validator's staking balance is slashed or + + frozen. + +## Storage proof contract logic + +Each replicator and validator will have their own storage account. The validator's account would be separate from their gossip id similiar to their vote account. These should be implemented as two programs one which handles the validator as the keysigner and one for the replicator. In that way when the programs reference other accounts, they can check the program id to ensure it is a validator or replicator account they are referencing. + +### SubmitMiningProof + +```text +SubmitMiningProof { + slot: u64, + sha_state: Hash, + signature: Signature, +}; +keys = [replicator_keypair] +``` + +Replicators create these after mining their stored ledger data for a certain hash value. The slot is the end slot of the segment of ledger they are storing, the sha\_state the result of the replicator using the hash function to sample their encrypted ledger segment. The signature is the signature that was created when they signed a PoH value for the current storage epoch. The list of proofs from the current storage epoch should be saved in the account state, and then transfered to a list of proofs for the previous epoch when the epoch passes. In a given storage epoch a given replicator should only submit proofs for one segment. + +The program should have a list of slots which are valid storage mining slots. This list should be maintained by keeping track of slots which are rooted slots in which a significant portion of the network has voted on with a high lockout value, maybe 32-votes old. Every SLOTS\_PER\_SEGMENT number of slots would be added to this set. The program should check that the slot is in this set. The set can be maintained by receiving a AdvertiseStorageRecentBlockHash and checking with its bank/Tower BFT state. + +The program should do a signature verify check on the signature, public key from the transaction submitter and the message of the previous storage epoch PoH value. + +### ProofValidation + +```text +ProofValidation { + proof_mask: Vec, +} +keys = [validator_keypair, replicator_keypair(s) (unsigned)] +``` + +A validator will submit this transaction to indicate that a set of proofs for a given segment are valid/not-valid or skipped where the validator did not look at it. The keypairs for the replicators that it looked at should be referenced in the keys so the program logic can go to those accounts and see that the proofs are generated in the previous epoch. The sampling of the storage proofs should be verified ensuring that the correct proofs are skipped by the validator according to the logic outlined in the validator behavior of sampling. + +The included replicator keys will indicate the the storage samples which are being referenced; the length of the proof\_mask should be verified against the set of storage proofs in the referenced replicator account\(s\), and should match with the number of proofs submitted in the previous storage epoch in the state of said replicator account. + +### ClaimStorageReward + +```text +ClaimStorageReward { +} +keys = [validator_keypair or replicator_keypair, validator/replicator_keypairs (unsigned)] +``` + +Replicators and validators will use this transaction to get paid tokens from a program state where SubmitStorageProof, ProofValidation and ChallengeProofValidations are in a state where proofs have been submitted and validated and there are no ChallengeProofValidations referencing those proofs. For a validator, it should reference the replicator keypairs to which it has validated proofs in the relevant epoch. And for a replicator it should reference validator keypairs for which it has validated and wants to be rewarded. + +### ChallengeProofValidation + +```text +ChallengeProofValidation { + proof_index: u64, + hash_seed_value: Vec, +} +keys = [replicator_keypair, validator_keypair] +``` + +This transaction is for catching lazy validators who are not doing the work to validate proofs. A replicator will submit this transaction when it sees a validator has approved a fake SubmitMiningProof transaction. Since the replicator is a light client not looking at the full chain, it will have to ask a validator or some set of validators for this information maybe via RPC call to obtain all ProofValidations for a certain segment in the previous storage epoch. The program will look in the validator account state see that a ProofValidation is submitted in the previous storage epoch and hash the hash\_seed\_value and see that the hash matches the SubmitMiningProof transaction and that the validator marked it as valid. If so, then it will save the challenge to the list of challenges that it has in its state. + +### AdvertiseStorageRecentBlockhash + +```text +AdvertiseStorageRecentBlockhash { + hash: Hash, + slot: u64, +} +``` + +Validators and replicators will submit this to indicate that a new storage epoch has passed and that the storage proofs which are current proofs should now be for the previous epoch. Other transactions should check to see that the epoch that they are referencing is accurate according to current chain state. + diff --git a/book/src/proposals/simple-payment-and-state-verification.md b/book/src/proposals/simple-payment-and-state-verification.md new file mode 100644 index 0000000000..844a8e24ac --- /dev/null +++ b/book/src/proposals/simple-payment-and-state-verification.md @@ -0,0 +1,110 @@ +# Simple Payment and State Verification + +It is often useful to allow low resourced clients to participate in a Solana cluster. Be this participation economic or contract execution, verification that a client's activity has been accepted by the network is typically expensive. This proposal lays out a mechanism for such clients to confirm that their actions have been committed to the ledger state with minimal resource expenditure and third-party trust. + +## A Naive Approach + +Validators store the signatures of recently confirmed transactions for a short period of time to ensure that they are not processed more than once. Validators provide a JSON RPC endpoint, which clients can use to query the cluster if a transaction has been recently processed. Validators also provide a PubSub notification, whereby a client registers to be notified when a given signature is observed by the validator. While these two mechanisms allow a client to verify a payment, they are not a proof and rely on completely trusting a fullnode. + +We will describe a way to minimize this trust using Merkle Proofs to anchor the fullnode's response in the ledger, allowing the client to confirm on their own that a sufficient number of their preferred validators have confirmed a transaction. Requiring multiple validator attestations further reduces trust in the fullnode, as it increases both the technical and economic difficulty of compromising several other network participants. + +## Light Clients + +A 'light client' is a cluster participant that does not itself run a fullnode. This light client would provide a level of security greater than trusting a remote fullnode, without requiring the light client to spend a lot of resources verifying the ledger. + +Rather than providing transaction signatures directly to a light client, the fullnode instead generates a Merkle Proof from the transaction of interest to the root of a Merkle Tree of all transactions in the including block. This Merkle Root is stored in a ledger entry which is voted on by validators, providing it consensus legitimacy. The additional level of security for a light client depends on an initial canonical set of validators the light client considers to be the stakeholders of the cluster. As that set is changed, the client can update its internal set of known validators with [receipts](simple-payment-and-state-verification.md#receipts). This may become challenging with a large number of delegated stakes. + +Fullnodes themselves may want to use light client APIs for performance reasons. For example, during the initial launch of a fullnode, the fullnode may use a cluster provided checkpoint of the state and verify it with a receipt. + +## Receipts + +A receipt is a minimal proof that; a transaction has been included in a block, that the block has been voted on by the client's preferred set of validators and that the votes have reached the desired confirmation depth. + +The receipts for both state and payments start with a Merkle Path from the value into a Bank-Merkle that has been voted on and included in the ledger. A chain of PoH Entries containing subsequent validator votes, deriving from the Bank-Merkle, is the confirmation proof. + +Clients can examine this ledger data and compute the finality using Solana's fork selection rules. + +### Payment Merkle Path + +A payment receipt is a data structure that contains a Merkle Path from a transaction to the required set of validator votes. + +An Entry-Merkle is a Merkle Root including all transactions in the entry, sorted by signature. + +![Block Merkle Diagram](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/spv-block-merkle.svg) + +A Block-Merkle is a Merkle root of all the Entry-Merkles sequenced in the block. Transaction status is necessary for the receipt because the state receipt is constructed for the block. Two transactions over the same state can appear in the block, and therefore, there is no way to infer from just the state whether a transaction that is committed to the ledger has succeeded or failed in modifying the intended state. It may not be necessary to encode the full status code, but a single status bit to indicate the transaction's success. + +### State Merkle Path + +A state receipt provides a confirmation that a specific state is committed at the end of the block. Inter-block state transitions do not generate a receipt. + +For example: + +* A sends 5 Lamports to B +* B spends 5 Lamports +* C sends 5 Lamports to A + +At the end of the block, A and B are in the exact same starting state, and any state receipt would point to the same value for A or B. + +The Bank-Merkle is computed from the Merkle Tree of the new state changes, along with the Previous Bank-Merkle, and the Block-Merkle. + +![Bank Merkle Diagram](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/spv-bank-merkle.svg) + +A state receipt contains only the state changes occurring in the block. A direct Merkle Path to the current Bank-Merkle guarantees the state value at that bank hash, but it cannot be used to generate a “current” receipt to the latest state if the state modification occurred in some previous block. There is no guarantee that the path provided by the validator is the latest one available out of all the previous Bank-Merkles. + +Clients that want to query the chain for a receipt of the "latest" state would need to create a transaction that would update the Merkle Path for that account, such as a credit of 0 Lamports. + +### Validator Votes + +Leaders should coalesce the validator votes by stake weight into a single entry. This will reduce the number of entries necessary to create a receipt. + +### Chain of Entries + +A receipt has a PoH link from the payment or state Merkle Path root to a list of consecutive validation votes. + +It contains the following: + +* State -> Bank-Merkle + + or + +* Transaction -> Entry-Merkle -> Block-Merkle -> Bank-Merkle + +And a vector of PoH entries: + +* Validator vote entries +* Ticks +* Light entries + +```text +/// This Entry definition skips over the transactions and only contains the +/// hash of the transactions used to modify PoH. +LightEntry { + /// The number of hashes since the previous Entry ID. + pub num_hashes: u64, + /// The SHA-256 hash `num_hashes` after the previous Entry ID. + hash: Hash, + /// The Merkle Root of the transactions encoded into the Entry. + entry_hash: Hash, +} +``` + +The light entries are reconstructed from Entries and simply show the entry Merkle Root that was mixed in to the PoH hash, instead of the full transaction set. + +Clients do not need the starting vote state. The [fork selection](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/book/src/fork-selection.md) algorithm is defined such that only votes that appear after the transaction provide finality for the transaction, and finality is independent of the starting state. + +### Verification + +A light client that is aware of the supermajority set validators can verify a receipt by following the Merkle Path to the PoH chain. The Bank-Merkle is the Merkle Root and will appear in votes included in an Entry. The light client can simulate [fork selection](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/book/src/fork-selection.md) for the consecutive votes and verify that the receipt is confirmed at the desired lockout threshold. + +### Synthetic State + +Synthetic state should be computed into the Bank-Merkle along with the bank generated state. + +For example: + +* Epoch validator accounts and their stakes and weights. +* Computed fee rates + +These values should have an entry in the Bank-Merkle. They should live under known accounts, and therefore have an exact address in the Merkle Path. + diff --git a/book/src/proposals/staking-rewards.md b/book/src/proposals/staking-rewards.md new file mode 100644 index 0000000000..06a6b75de0 --- /dev/null +++ b/book/src/proposals/staking-rewards.md @@ -0,0 +1,95 @@ +# Staking Rewards + +A Proof of Stake \(PoS\), \(i.e. using in-protocol asset, SOL, to provide secure consensus\) design is outlined here. Solana implements a proof of stake reward/security scheme for validator nodes in the cluster. The purpose is threefold: + +* Align validator incentives with that of the greater cluster through + + skin-in-the-game deposits at risk + +* Avoid 'nothing at stake' fork voting issues by implementing slashing rules + + aimed at promoting fork convergence + +* Provide an avenue for validator rewards provided as a function of validator + + participation in the cluster. + +While many of the details of the specific implementation are currently under consideration and are expected to come into focus through specific modeling studies and parameter exploration on the Solana testnet, we outline here our current thinking on the main components of the PoS system. Much of this thinking is based on the current status of Casper FFG, with optimizations and specific attributes to be modified as is allowed by Solana's Proof of History \(PoH\) blockchain data structure. + +## General Overview + +Solana's ledger validation design is based on a rotating, stake-weighted selected leader broadcasting transactions in a PoH data structure to validating nodes. These nodes, upon receiving the leader's broadcast, have the opportunity to vote on the current state and PoH height by signing a transaction into the PoH stream. + +To become a Solana validator, a fullnode must deposit/lock-up some amount of SOL in a contract. This SOL will not be accessible for a specific time period. The precise duration of the staking lockup period has not been determined. However we can consider three phases of this time for which specific parameters will be necessary: + +* _Warm-up period_: which SOL is deposited and inaccessible to the node, + + however PoH transaction validation has not begun. Most likely on the order of + + days to weeks + +* _Validation period_: a minimum duration for which the deposited SOL will be + + inaccessible, at risk of slashing \(see slashing rules below\) and earning + + rewards for the validator participation. Likely duration of months to a + + year. + +* _Cool-down period_: a duration of time following the submission of a + + 'withdrawal' transaction. During this period validation responsibilities have + + been removed and the funds continue to be inaccessible. Accumulated rewards + + should be delivered at the end of this period, along with the return of the + + initial deposit. + +Solana's trustless sense of time and ordering provided by its PoH data structure, along with its [turbine](https://www.youtube.com/watch?v=qt_gDRXHrHQ&t=1s) data broadcast and transmission design, should provide sub-second transaction confirmation times that scale with the log of the number of nodes in the cluster. This means we shouldn't have to restrict the number of validating nodes with a prohibitive 'minimum deposits' and expect nodes to be able to become validators with nominal amounts of SOL staked. At the same time, Solana's focus on high-throughput should create incentive for validation clients to provide high-performant and reliable hardware. Combined with potential a minimum network speed threshold to join as a validation-client, we expect a healthy validation delegation market to emerge. To this end, Solana's testnet will lead into a "Tour de SOL" validation-client competition, focusing on throughput and uptime to rank and reward testnet validators. + +## Slashing rules + +Unlike Proof of Work \(PoW\) where off-chain capital expenses are already deployed at the time of block construction/voting, PoS systems require capital-at-risk to prevent a logical/optimal strategy of multiple chain voting. We intend to implement slashing rules which, if broken, result some amount of the offending validator's deposited stake to be removed from circulation. Given the ordering properties of the PoH data structure, we believe we can simplify our slashing rules to the level of a voting lockout time assigned per vote. + +I.e. Each vote has an associated lockout time \(PoH duration\) that represents a duration by any additional vote from that validator must be in a PoH that contains the original vote, or a portion of that validator's stake is slashable. This duration time is a function of the initial vote PoH count and all additional vote PoH counts. It will likely take the form: + +Lockouti\(PoHi, PoHj\) = PoHj + K \* exp\(\(PoHj - PoHi\) / K\) + +Where PoHi is the height of the vote that the lockout is to be applied to and PoHj is the height of the current vote on the same fork. If the validator submits a vote on a different PoH fork on any PoHk where k > j > i and PoHk < Lockout\(PoHi, PoHj\), then a portion of that validator's stake is at risk of being slashed. + +In addition to the functional form lockout described above, early implementation may be a numerical approximation based on a First In, First Out \(FIFO\) data structure and the following logic: + +* FIFO queue holding 32 votes per active validator +* new votes are pushed on top of queue \(`push_front`\) +* expired votes are popped off top \(`pop_front`\) +* as votes are pushed into the queue, the lockout of each queued vote doubles +* votes are removed from back of queue if `queue.len() > 32` +* the earliest and latest height that has been removed from the back of the + + queue should be stored + +It is likely that a reward will be offered as a % of the slashed amount to any node that submits proof of this slashing condition being violated to the PoH. + +### Partial Slashing + +In the schema described so far, when a validator votes on a given PoH stream, they are committing themselves to that fork for a time determined by the vote lockout. An open question is whether validators will be hesitant to begin voting on an available fork if the penalties are perceived too harsh for an honest mistake or flipped bit. + +One way to address this concern would be a partial slashing design that results in a slashable amount as a function of either: + +1. the fraction of validators, out of the total validator pool, that were also + + slashed during the same time period \(ala Casper\) + +2. the amount of time since the vote was cast \(e.g. a linearly increasing % of + + total deposited as slashable amount over time\), or both. + +This is an area currently under exploration + +## Penalties + +As discussed in the [Economic Design](ed_overview/) section, annual validator interest rates are to be specified as a function of total percentage of circulating supply that has been staked. The cluster rewards validators who are online and actively participating in the validation process throughout the entirety of their _validation period_. For validators that go offline/fail to validate transactions during this period, their annual reward is effectively reduced. + +Similarly, we may consider an algorithmic reduction in a validator's active amount staked amount in the case that they are offline. I.e. if a validator is inactive for some amount of time, either due to a partition or otherwise, the amount of their stake that is considered ‘active’ \(eligible to earn rewards\) may be reduced. This design would be structured to help long-lived partitions to eventually reach finality on their respective chains as the % of non-voting total stake is reduced over time until a super-majority can be achieved by the active validators in each partition. Similarly, upon re-engaging, the ‘active’ amount staked will come back online at some defined rate. Different rates of stake reduction may be considered depending on the size of the partition/active set. + diff --git a/book/src/proposals/validator-proposal.md b/book/src/proposals/validator-proposal.md new file mode 100644 index 0000000000..019192dc5f --- /dev/null +++ b/book/src/proposals/validator-proposal.md @@ -0,0 +1,36 @@ +# Validator + +## History + +When we first started Solana, the goal was to de-risk our TPS claims. We knew that between optimistic concurrency control and sufficiently long leader slots, that PoS consensus was not the biggest risk to TPS. It was GPU-based signature verification, software pipelining and concurrent banking. Thus, the TPU was born. After topping 100k TPS, we split the team into one group working toward 710k TPS and another to flesh out the validator pipeline. Hence, the TVU was born. The current architecture is a consequence of incremental development with that ordering and project priorities. It is not a reflection of what we ever believed was the most technically elegant cross-section of those technologies. In the context of leader rotation, the strong distinction between leading and validating is blurred. + +## Difference between validating and leading + +The fundamental difference between the pipelines is when the PoH is present. In a leader, we process transactions, removing bad ones, and then tag the result with a PoH hash. In the validator, we verify that hash, peel it off, and process the transactions in exactly the same way. The only difference is that if a validator sees a bad transaction, it can't simply remove it like the leader does, because that would cause the PoH hash to change. Instead, it rejects the whole block. The other difference between the pipelines is what happens _after_ banking. The leader broadcasts entries to downstream validators whereas the validator will have already done that in RetransmitStage, which is a confirmation time optimization. The validation pipeline, on the other hand, has one last step. Any time it finishes processing a block, it needs to weigh any forks it's observing, possibly cast a vote, and if so, reset its PoH hash to the block hash it just voted on. + +## Proposed Design + +We unwrap the many abstraction layers and build a single pipeline that can toggle leader mode on whenever the validator's ID shows up in the leader schedule. + +![Validator block diagram](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/validator-proposal.svg) + +## Notable changes + +* No threads are shut down to switch out of leader mode. Instead, FetchStage + + should forward transactions to the next leader. + +* Hoist FetchStage and BroadcastStage out of TPU +* Blocktree renamed to Blockstore +* BankForks renamed to Banktree +* TPU moves to new socket-free crate called solana-tpu. +* TPU's BankingStage absorbs ReplayStage +* TVU goes away +* New RepairStage absorbs Blob Fetch Stage and repair requests +* JSON RPC Service is optional - used for debugging. It should instead be part + + of a separate `solana-blockstreamer` executable. + +* New MulticastStage absorbs retransmit part of RetransmitStage +* MulticastStage downstream of Blockstore + diff --git a/book/src/proposals/vote-signing-to-implement.md b/book/src/proposals/vote-signing-to-implement.md new file mode 100644 index 0000000000..a6e94e528f --- /dev/null +++ b/book/src/proposals/vote-signing-to-implement.md @@ -0,0 +1,111 @@ +# Secure Vote Signing + +## Secure Vote Signing + +This design describes additional vote signing behavior that will make the process more secure. + +Currently, Solana implements a vote-signing service that evaluates each vote to ensure it does not violate a slashing condition. The service could potentially have different variations, depending on the hardware platform capabilities. In particular, it could be used in conjunction with a secure enclave \(such as SGX\). The enclave could generate an asymmetric key, exposing an API for user \(untrusted\) code to sign the vote transactions, while keeping the vote-signing private key in its protected memory. + +The following sections outline how this architecture would work: + +### Message Flow + +1. The node initializes the enclave at startup + * The enclave generates an asymmetric key and returns the public key to the + + node + + * The keypair is ephemeral. A new keypair is generated on node bootup. A + + new keypair might also be generated at runtime based on some TBD + + criteria. + + * The enclave returns its attestation report to the node +2. The node performs attestation of the enclave \(e.g using Intel's IAS APIs\) + * The node ensures that the Secure Enclave is running on a TPM and is + + signed by a trusted party +3. The stakeholder of the node grants ephemeral key permission to use its stake. + + This process is TBD. + +4. The node's untrusted, non-enclave software calls trusted enclave software + + using its interface to sign transactions and other data. + + * In case of vote signing, the node needs to verify the PoH. The PoH + + verification is an integral part of signing. The enclave would be + + presented with some verifiable data to check before signing the vote. + + * The process of generating the verifiable data in untrusted space is TBD + +### PoH Verification + +1. When the node votes on an en entry `X`, there's a lockout period `N`, for + + which it cannot vote on a fork that does not contain `X` in its history. + +2. Every time the node votes on the derivative of `X`, say `X+y`, the lockout + + period for `X` increases by a factor `F` \(i.e. the duration node cannot vote on + + a fork that does not contain `X` increases\). + + * The lockout period for `X+y` is still `N` until the node votes again. + +3. The lockout period increment is capped \(e.g. factor `F` applies maximum 32 + + times\). + +4. The signing enclave must not sign a vote that violates this policy. This + + means + + * Enclave is initialized with `N`, `F` and `Factor cap` + * Enclave stores `Factor cap` number of entry IDs on which the node had + + previously voted + + * The sign request contains the entry ID for the new vote + * Enclave verifies that new vote's entry ID is on the correct fork + + \(following the rules \#1 and \#2 above\) + +### Ancestor Verification + +This is alternate, albeit, less certain approach to verifying voting fork. 1. The validator maintains an active set of nodes in the cluster 2. It observes the votes from the active set in the last voting period 3. It stores the ancestor/last\_tick at which each node voted 4. It sends new vote request to vote-signing service + +* It includes previous votes from nodes in the active set, and their + + corresponding ancestors + + 1. The signer checks if the previous votes contains a vote from the validator, + + and the vote ancestor matches with majority of the nodes + +* It signs the new vote if the check is successful +* It asserts \(raises an alarm of some sort\) if the check is unsuccessful + +The premise is that the validator can be spoofed at most once to vote on incorrect data. If someone hijacks the validator and submits a vote request for bogus data, that vote will not be included in the PoH \(as it'll be rejected by the cluster\). The next time the validator sends a request to sign the vote, the signing service will detect that validator's last vote is missing \(as part of + +## 5 above\). + +### Fork determination + +Due to the fact that the enclave cannot process PoH, it has no direct knowledge of fork history of a submitted validator vote. Each enclave should be initiated with the current _active set_ of public keys. A validator should submit its current vote along with the votes of the active set \(including itself\) that it observed in the slot of its previous vote. In this way, the enclave can surmise the votes accompanying the validator's previous vote and thus the fork being voted on. This is not possible for the validator's initial submitted vote, as it will not have a 'previous' slot to reference. To account for this, a short voting freeze should apply until the second vote is submitted containing the votes within the active set, along with it's own vote, at the height of the initial vote. + +### Enclave configuration + +A staking client should be configurable to prevent voting on inactive forks. This mechanism should use the client's known active set `N_active` along with a threshold vote `N_vote` and a threshold depth `N_depth` to determine whether or not to continue voting on a submitted fork. This configuration should take the form of a rule such that the client will only vote on a fork if it observes more than `N_vote` at `N_depth`. Practically, this represents the client from confirming that it has observed some probability of economic finality of the submitted fork at a depth where an additional vote would create a lockout for an undesirable amount of time if that fork turns out not to be live. + +### Challenges + +1. Generation of verifiable data in untrusted space for PoH verification in the + + enclave. + +2. Need infrastructure for granting stake to an ephemeral key. + diff --git a/book/src/running-replicator.md b/book/src/running-replicator.md index 4cd88d2957..607a917657 100644 --- a/book/src/running-replicator.md +++ b/book/src/running-replicator.md @@ -1,105 +1,99 @@ -## Running a Replicator +# Running a Replicator + This document describes how to setup a replicator in the testnet -Please note some of the information and instructions described here may change -in future releases. +Please note some of the information and instructions described here may change in future releases. -### Overview -Replicators are specialized light clients. They download a part of the -ledger (a.k.a Segment) and store it. They earn rewards for storing segments. +## Overview -The testnet features a validator running at testnet.solana.com, which -serves as the entrypoint to the cluster for your replicator node. +Replicators are specialized light clients. They download a part of the ledger \(a.k.a Segment\) and store it. They earn rewards for storing segments. -Additionally there is a blockexplorer available at -[http://testnet.solana.com/](http://testnet.solana.com/). +The testnet features a validator running at testnet.solana.com, which serves as the entrypoint to the cluster for your replicator node. -The testnet is configured to reset the ledger daily, or sooner -should the hourly automated cluster sanity test fail. +Additionally there is a blockexplorer available at [http://testnet.solana.com/](http://testnet.solana.com/). -### Machine Requirements -Replicators don't need specialized hardware. Anything with more than -128GB of disk space will be able to participate in the cluster as a replicator node. +The testnet is configured to reset the ledger daily, or sooner should the hourly automated cluster sanity test fail. -Currently the disk space requirements are very low but we expect them to change -in the future. +## Machine Requirements -Prebuilt binaries are available for Linux x86_64 (Ubuntu 18.04 recommended), -macOS, and Windows. +Replicators don't need specialized hardware. Anything with more than 128GB of disk space will be able to participate in the cluster as a replicator node. -#### Confirm The Testnet Is Reachable -Before starting a replicator node, sanity check that the cluster is accessible -to your machine by running some simple commands. If any of the commands fail, -please retry 5-10 minutes later to confirm the testnet is not just restarting -itself before debugging further. +Currently the disk space requirements are very low but we expect them to change in the future. + +Prebuilt binaries are available for Linux x86\_64 \(Ubuntu 18.04 recommended\), macOS, and Windows. + +### Confirm The Testnet Is Reachable + +Before starting a replicator node, sanity check that the cluster is accessible to your machine by running some simple commands. If any of the commands fail, please retry 5-10 minutes later to confirm the testnet is not just restarting itself before debugging further. Fetch the current transaction count over JSON RPC: + ```bash $ curl -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1, "method":"getTransactionCount"}' http://testnet.solana.com:8899 ``` Inspect the blockexplorer at [http://testnet.solana.com/](http://testnet.solana.com/) for activity. -View the [metrics dashboard]( -https://metrics.solana.com:3000/d/testnet-beta/testnet-monitor-beta?var-testnet=testnet) -for more detail on cluster activity. +View the [metrics dashboard](https://metrics.solana.com:3000/d/testnet-beta/testnet-monitor-beta?var-testnet=testnet) for more detail on cluster activity. -### Replicator Setup -##### Obtaining The Software -##### Bootstrap with `solana-install` +## Replicator Setup -The `solana-install` tool can be used to easily install and upgrade the cluster -software. +#### Obtaining The Software + +#### Bootstrap with `solana-install` + +The `solana-install` tool can be used to easily install and upgrade the cluster software. + +#### Linux and mac OS -##### Linux and mac OS ```bash -$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.0/install/solana-install-init.sh | sh -s +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.1/install/solana-install-init.sh | sh -s ``` -Alternatively build the `solana-install` program from source and run the -following command to obtain the same result: +Alternatively build the `solana-install` program from source and run the following command to obtain the same result: + ```bash $ solana-install init ``` -##### Windows -Download and install **solana-install-init** from -[https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest) +#### Windows -After a successful install, `solana-install update` may be used to -easily update the software to a newer version at any time. +Download and install **solana-install-init** from [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest) + +After a successful install, `solana-install update` may be used to easily update the software to a newer version at any time. + +#### Download Prebuilt Binaries -##### Download Prebuilt Binaries If you would rather not use `solana-install` to manage the install, you can manually download and install the binaries. -##### Linux -Download the binaries by navigating to -[https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), -download **solana-release-x86_64-unknown-linux-gnu.tar.bz2**, then extract the -archive: +#### Linux + +Download the binaries by navigating to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), download **solana-release-x86\_64-unknown-linux-gnu.tar.bz2**, then extract the archive: + ```bash $ tar jxf solana-release-x86_64-unknown-linux-gnu.tar.bz2 $ cd solana-release/ $ export PATH=$PWD/bin:$PATH ``` -##### mac OS -Download the binaries by navigating to -[https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), -download **solana-release-x86_64-apple-darwin.tar.bz2**, then extract the -archive: + +#### mac OS + +Download the binaries by navigating to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), download **solana-release-x86\_64-apple-darwin.tar.bz2**, then extract the archive: + ```bash $ tar jxf solana-release-x86_64-apple-darwin.tar.bz2 $ cd solana-release/ $ export PATH=$PWD/bin:$PATH ``` -##### Windows -Download the binaries by navigating to -[https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), -download **solana-release-x86_64-pc-windows-msvc.tar.bz2**, then extract it into a folder. -It is a good idea to add this extracted folder to your windows PATH. -### Starting The Replicator +#### Windows + +Download the binaries by navigating to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), download **solana-release-x86\_64-pc-windows-msvc.tar.bz2**, then extract it into a folder. It is a good idea to add this extracted folder to your windows PATH. + +## Starting The Replicator + Try running following command to join the gossip network and view all the other nodes in the cluster: + ```bash $ solana-gossip --entrypoint testnet.solana.com:8001 spy # Press ^C to exit @@ -108,46 +102,56 @@ $ solana-gossip --entrypoint testnet.solana.com:8001 spy Now configure the keypairs for your replicator by running: Navigate to the solana install location and open a cmd prompt + ```bash $ solana-keygen new -o replicator-keypair.json $ solana-keygen new -o storage-keypair.json ``` -Use solana-keygen to show the public keys for each of the keypairs, -they will be needed in the next step: -- Windows -```bash -# The replicator's identity -$ solana-keygen pubkey replicator-keypair.json -$ solana-keygen pubkey storage-keypair.json -``` -- Linux and mac OS -```bash -$ export REPLICATOR_IDENTITY=$(solana-keygen pubkey replicator-keypair.json) -$ export STORAGE_IDENTITY=$(solana-keygen pubkey storage-keypair.json) +Use solana-keygen to show the public keys for each of the keypairs, they will be needed in the next step: -``` +* Windows + + ```bash + # The replicator's identity + $ solana-keygen pubkey replicator-keypair.json + $ solana-keygen pubkey storage-keypair.json + ``` + +* Linux and mac OS + + \`\`\`bash + + $ export REPLICATOR\_IDENTITY=$\(solana-keygen pubkey replicator-keypair.json\) + + $ export STORAGE\_IDENTITY=$\(solana-keygen pubkey storage-keypair.json\) + +```text Then set up the storage accounts for your replicator by running: ```bash -$ solana --keypair replicator-keypair.json airdrop 100000 lamports +$ solana --keypair replicator-keypair.json airdrop 100000 $ solana --keypair replicator-keypair.json create-replicator-storage-account $REPLICATOR_IDENTITY $STORAGE_IDENTITY ``` + Note: Every time the testnet restarts, run the steps to setup the replicator accounts again. To start the replicator: + ```bash $ solana-replicator --entrypoint testnet.solana.com:8001 --identity replicator-keypair.json --storage-keypair storage-keypair.json --ledger replicator-ledger ``` -### Verify Replicator Setup -From another console, confirm the IP address and **identity pubkey** of your replicator is visible in the -gossip network by running: +## Verify Replicator Setup + +From another console, confirm the IP address and **identity pubkey** of your replicator is visible in the gossip network by running: + ```bash $ solana-gossip --entrypoint testnet.solana.com:8001 spy ``` -Provide the **storage account pubkey** to the `solana show-storage-account` command to view -the recent mining activity from your replicator: +Provide the **storage account pubkey** to the `solana show-storage-account` command to view the recent mining activity from your replicator: + ```bash $ solana --keypair storage-keypair.json show-storage-account $STORAGE_IDENTITY ``` + diff --git a/book/src/running-validator/README.md b/book/src/running-validator/README.md new file mode 100644 index 0000000000..6f2e56021f --- /dev/null +++ b/book/src/running-validator/README.md @@ -0,0 +1,28 @@ +# Running a Validator + +This document describes how to participate in the Solana testnet as a validator node. + +Please note some of the information and instructions described here may change in future releases, and documentation will be updated for mainnet participation. + +## Overview + +Solana currently maintains several testnets, each featuring a validator that can serve as the entrypoint to the cluster for your validator. + +Current testnet entrypoints: + +* Stable, testnet.solana.com +* Beta, beta.testnet.solana.com +* Edge, edge.testnet.solana.com + +Solana may launch special testnets for validator participation; we will provide you with a specific entrypoint URL to use. + +Prior to mainnet, the testnets may be running different versions of solana software, which may feature breaking changes. For information on choosing a testnet and finding software version info, jump to [Choosing a Testnet](validator-testnet.md). + +The testnets are configured to reset the ledger daily, or sooner, should the hourly automated cluster sanity test fail. + +There is a network explorer that shows the status of solana testnets available at [http://explorer.solana.com/](https://explorer.solana.com/). + +There is a **\#validator-support** Discord channel available to reach other testnet participants, [https://discord.gg/pquxPsq](https://discord.gg/pquxPsq). + +Also we'd love it if you choose to register your validator node with us at [https://forms.gle/LfFscZqJELbuUP139](https://forms.gle/LfFscZqJELbuUP139). + diff --git a/book/src/running-validator/validator-faq.md b/book/src/running-validator/validator-faq.md new file mode 100644 index 0000000000..a61b381358 --- /dev/null +++ b/book/src/running-validator/validator-faq.md @@ -0,0 +1,4 @@ +# FAQ + +Coming soon... + diff --git a/book/src/running-validator/validator-hardware.md b/book/src/running-validator/validator-hardware.md new file mode 100644 index 0000000000..f6a5d29204 --- /dev/null +++ b/book/src/running-validator/validator-hardware.md @@ -0,0 +1,24 @@ +# Hardware Requirements + +Since the testnet is not intended for stress testing of max transaction throughput, a higher-end machine with a GPU is not necessary to participate. + +However ensure the machine used is not behind a residential NAT to avoid NAT traversal issues. A cloud-hosted machine works best. **Ensure that IP ports 8000 through 10000 are not blocked for Internet inbound and outbound traffic.** + +Prebuilt binaries are available for Linux x86\_64 \(Ubuntu 18.04 recommended\). MacOS or WSL users may build from source. + +## Recommended Setups + +For a performance testnet with many transactions we have some preliminary recommended setups: + +| | Low end | Medium end | High end | Notes | +| :--- | :--- | :--- | :--- | :--- | +| CPU | AMD Threadripper 1900x | AMD Threadripper 2920x | AMD Threadripper 2950x | Consider a 10Gb-capable motherboard with as many PCIe lanes and m.2 slots as possible. | +| RAM | 16GB | 32GB | 64GB | | +| OS Drive | Samsung 860 Evo 2TB | Samsung 860 Evo 4TB | Samsung 860 Evo 4TB | Or equivalent SSD | +| Accounts Drive\(s\) | None | Samsung 970 Pro 1TB | 2x Samsung 970 Pro 1TB | | +| GPU | 4x Nvidia 1070 or 2x Nvidia 1080 Ti or 2x Nvidia 2070 | 2x Nvidia 2080 Ti | 4x Nvidia 2080 Ti | Any number of cuda-capable GPUs are supported on Linux platforms. | + +## GPU Requirements + +CUDA is required to make use of the GPU on your system. The provided Solana release binaries are built on Ubuntu 18.04 with [CUDA Toolkit 10.1 update 1"](https://developer.nvidia.com/cuda-toolkit-archive). If your machine is using a different CUDA version then you will need to rebuild from source. + diff --git a/book/src/running-validator/validator-info.md b/book/src/running-validator/validator-info.md new file mode 100644 index 0000000000..e2b1a65b89 --- /dev/null +++ b/book/src/running-validator/validator-info.md @@ -0,0 +1,36 @@ +# Publishing Validator Info + +You can publish your validator information to the chain to be publicly visible to other users. + +## Run solana-validator-info + +Run the solana-validator-info CLI to populate a validator-info account: + +```bash +$ solana-validator-info publish ~/validator-keypair.json +``` + +Optional fields for VALIDATOR\_INFO\_ARGS: + +* Website +* Keybase Username +* Details + +## Keybase + +Including a Keybase username allows client applications \(like the Solana Network Explorer\) to automatically pull in your validator public profile, including cryptographic proofs, brand identity, etc. To connect your validator pubkey with Keybase: + +1. Join [https://keybase.io/](https://keybase.io/) and complete the profile for your validator +2. Add your validator **identity pubkey** to Keybase: + * Create an empty file on your local computer called `validator-` + * In Keybase, navigate to the Files section, and upload your pubkey file to + + a `solana` subdirectory in your public folder: `/keybase/public//solana` + + * To check your pubkey, ensure you can successfully browse to + + `https://keybase.pub//solana/validator-` +3. Add or update your `solana-validator-info` with your Keybase username. The + + CLI will verify the `validator-` file + diff --git a/book/src/running-validator/validator-monitor.md b/book/src/running-validator/validator-monitor.md new file mode 100644 index 0000000000..898c595f94 --- /dev/null +++ b/book/src/running-validator/validator-monitor.md @@ -0,0 +1,108 @@ +# Monitoring a Validator + +When `validator.sh` starts, it will output a validator configuration that looks similar to: + +```bash +======================[ validator configuration ]====================== +identity pubkey: 4ceWXsL3UJvn7NYZiRkw7NsryMpviaKBDYr8GK7J61Dm +vote pubkey: 2ozWvfaXQd1X6uKh8jERoRGApDqSqcEy6fF1oN13LL2G +ledger: ... +accounts: ... +====================================================================== +``` + +## Check Gossip + +The **identity pubkey** for your validator can also be found by running: + +```bash +$ solana-keygen pubkey ~/validator-keypair.json +``` + +From another console, confirm the IP address and **identity pubkey** of your validator is visible in the gossip network by running: + +```bash +$ solana-gossip --entrypoint testnet.solana.com:8001 spy +``` + +## Check Vote Activity + +The vote pubkey for the validator can be found by running: + +```bash +$ solana-keygen pubkey ~/validator-vote-keypair.json +``` + +Provide the **vote pubkey** to the `solana show-vote-account` command to view the recent voting activity from your validator: + +```bash +$ solana show-vote-account 2ozWvfaXQd1X6uKh8jERoRGApDqSqcEy6fF1oN13LL2G +``` + +## Check Your Balance + +Your lamport balance should decrease by the transaction fee amount as your validator submits votes, and increase after serving as the leader: + +```bash +$ solana balance +``` + +## Check Slot Number + +After your validator boots, it may take some time to catch up with the cluster. Use the `get-slot` command to view the current slot that the cluster is processing: + +```bash +$ solana get-slot +``` + +The current slot that your validator is processing can then been seen with: + +```bash +$ solana --url http://127.0.0.1:8899 get-slot +``` + +Until your validator has caught up, it will not be able to vote successfully and stake cannot be delegated to it. + +Also if you find the cluster's slot advancing faster than yours, you will likely never catch up. This typically implies some kind of networking issue between your validator and the rest of the cluster. + +## Get Cluster Info + +There are several useful JSON-RPC endpoints for monitoring your validator on the cluster, as well as the health of the cluster: + +```bash +# Similar to solana-gossip, you should see your validator in the list of cluster nodes +$ curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getClusterNodes"}' http://testnet.solana.com:8899 +# If your validator is properly voting, it should appear in the list of `current` vote accounts. If staked, `stake` should be > 0 +$ curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getVoteAccounts"}' http://testnet.solana.com:8899 +# Returns the current leader schedule +$ curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getLeaderSchedule"}' http://testnet.solana.com:8899 +# Returns info about the current epoch. slotIndex should progress on subsequent calls. +curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getEpochInfo"}' http://testnet.solana.com:8899 +``` + +## Validator Metrics + +Metrics are available for local monitoring of your validator. + +Docker must be installed and the current user added to the docker group. Then download `solana-metrics.tar.bz2` from the Github Release and run + +```bash +$ tar jxf solana-metrics.tar.bz2 +$ cd solana-metrics/ +$ ./start.sh +``` + +A local InfluxDB and Grafana instance is now running on your machine. Define `SOLANA_METRICS_CONFIG` in your environment as described at the end of the `start.sh` output and restart your validator. + +Metrics should now be streaming and visible from your local Grafana dashboard. + +## Timezone For Log Messages + +Log messages emitted by your validator include a timestamp. When sharing logs with others to help triage issues, that timestamp can cause confusion as it does not contain timezone information. + +To make it easier to compare logs between different sources we request that everybody use Pacific Time on their validator nodes. In Linux this can be accomplished by running: + +```bash +$ sudo ln -sf /usr/share/zoneinfo/America/Los_Angeles /etc/localtime +``` + diff --git a/book/src/running-validator/validator-software.md b/book/src/running-validator/validator-software.md new file mode 100644 index 0000000000..b4ba4ea991 --- /dev/null +++ b/book/src/running-validator/validator-software.md @@ -0,0 +1,60 @@ +# Installing the Validator Software + +## Bootstrap with `solana-install` + +The `solana-install` tool can be used to easily install and upgrade the validator software on Linux x86\_64 and mac OS systems. + +```bash +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.0/install/solana-install-init.sh | sh -s +``` + +Alternatively build the `solana-install` program from source and run the following command to obtain the same result: + +```bash +$ solana-install init +``` + +After a successful install, `solana-install update` may be used to easily update the cluster software to a newer version at any time. + +## Download Prebuilt Binaries + +If you would rather not use `solana-install` to manage the install, you can manually download and install the binaries. + +### Linux + +Download the binaries by navigating to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), download **solana-release-x86\_64-unknown-linux-gnu.tar.bz2**, then extract the archive: + +```bash +$ tar jxf solana-release-x86_64-unknown-linux-gnu.tar.bz2 +$ cd solana-release/ +$ export PATH=$PWD/bin:$PATH +``` + +### mac OS + +Download the binaries by navigating to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), download **solana-release-x86\_64-apple-darwin.tar.bz2**, then extract the archive: + +```bash +$ tar jxf solana-release-x86_64-apple-darwin.tar.bz2 +$ cd solana-release/ +$ export PATH=$PWD/bin:$PATH +``` + +## Build From Source + +If you are unable to use the prebuilt binaries or prefer to build it yourself from source, navigate to [https://github.com/solana-labs/solana/releases/latest](https://github.com/solana-labs/solana/releases/latest), and download the **Source Code** archive. Extract the code and build the binaries with: + +```bash +$ ./scripts/cargo-install-all.sh . +$ export PATH=$PWD/bin:$PATH +``` + +If building for CUDA \(Linux only\), fetch the perf-libs first then include the `cuda` feature flag when building: + +```bash +$ ./fetch-perf-libs.sh +$ source target/perf-libs/env.sh +$ ./scripts/cargo-install-all.sh . cuda +$ export PATH=$PWD/bin:$PATH +``` + diff --git a/book/src/running-validator/validator-stake.md b/book/src/running-validator/validator-stake.md new file mode 100644 index 0000000000..3ccc6e491e --- /dev/null +++ b/book/src/running-validator/validator-stake.md @@ -0,0 +1,40 @@ +# Staking + +When your validator starts, it will have no stake, which means it will be ineligible to become leader. + +Adding stake can be accomplished by using the `solana` CLI + +First create a stake account keypair with `solana-keygen`: + +```bash +$ solana-keygen new -o ~/validator-config/stake-keypair.json +``` + +and use the cli's `delegate-stake` command to stake your validator with 42 lamports: + +```bash +$ solana delegate-stake ~/validator-config/stake-keypair.json ~/validator-vote-keypair.json 42 +``` + +Note that stakes need to warm up, and warmup increments are applied at Epoch boundaries, so it can take an hour or more for the change to fully take effect. + +Assuming your node is voting, now you're up and running and generating validator rewards. You'll want to periodically redeem/claim your rewards: + +```bash +$ solana-wallet redeem-vote-credits ~/validator-config/stake-keypair.json ~/validator-vote-keypair.json +``` + +The rewards lamports earned are split between your stake account and the vote account according to the commission rate set in the vote account. + +Stake can be deactivated by running: + +```bash +$ solana deactivate-stake ~/validator-config/stake-keypair.json ~/validator-vote-keypair.json +``` + +The stake will cool down, deactivate over time. While cooling down, your stake will continue to earn rewards. + +Note that a stake account may only be used once, so after deactivation, use the cli's `withdraw-stake` command to recover the previously staked lamports. + +Be sure and redeem your credits before withdrawing all your lamports. Once the account is fully withdrawn, the account is destroyed. + diff --git a/book/src/running-validator/validator-start.md b/book/src/running-validator/validator-start.md new file mode 100644 index 0000000000..71650acfcc --- /dev/null +++ b/book/src/running-validator/validator-start.md @@ -0,0 +1,111 @@ +# Starting a Validator + +## Confirm The Testnet Is Reachable + +Before attaching a validator node, sanity check that the cluster is accessible to your machine by running some simple commands. If any of the commands fail, please retry 5-10 minutes later to confirm the testnet is not just restarting itself before debugging further. + +Fetch the current transaction count over JSON RPC: + +```bash +$ curl -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1, "method":"getTransactionCount"}' http://testnet.solana.com:8899 +``` + +Inspect the network explorer at [https://explorer.solana.com/](https://explorer.solana.com/) for activity. + +View the [metrics dashboard](https://metrics.solana.com:3000/d/testnet-beta/testnet-monitor-beta?var-testnet=testnet) for more detail on cluster activity. + +## Confirm your Installation + +Sanity check that you are able to interact with the cluster by receiving a small airdrop of lamports from the testnet drone: + +```bash +$ solana set --url http://testnet.solana.com:8899 +$ solana get +$ solana airdrop 123 +$ solana balance +``` + +Also try running following command to join the gossip network and view all the other nodes in the cluster: + +```bash +$ solana-gossip --entrypoint testnet.solana.com:8001 spy +# Press ^C to exit +``` + +## Start your Validator + +Create an identity keypair for your validator by running: + +```bash +$ solana-keygen new -o ~/validator-keypair.json +``` + +### Wallet Configuration + +You can set solana configuration to use your validator keypair for all following commands: + +```bash +$ solana set --keypair ~/validator-keypair.json +``` + +**All following solana commands assume you have set `--keypair` config to** your validator identity keypair.\*\* If you haven't, you will need to add the `--keypair` argument to each command, like: + +```bash +$ solana --keypair ~/validator-keypair.json airdrop 1000 +``` + +\(You can always override the set configuration by explicitly passing the `--keypair` argument with a command.\) + +### Validator Start + +Airdrop yourself some lamports to get started: + +```bash +$ solana airdrop 1000 +``` + +Your validator will need a vote account. Create it now with the following commands: + +```bash +$ solana-keygen new -o ~/validator-vote-keypair.json +$ solana create-vote-account ~/validator-vote-keypair.json ~/validator-keypair.json 1 +``` + +Then use one of the following commands, depending on your installation choice, to start the node: + +If this is a `solana-install`-installation: + +```bash +$ validator.sh --identity ~/validator-keypair.json --voting-keypair ~/validator-vote-keypair.json --ledger ~/validator-config --rpc-port 8899 --poll-for-new-genesis-block --entrypoint testnet.solana.com +``` + +Alternatively, the `solana-install run` command can be used to run the validator node while periodically checking for and applying software updates: + +```bash +$ solana-install run validator.sh -- --identity ~/validator-keypair.json --voting-keypair ~/validator-vote-keypair.json --ledger ~/validator-config --rpc-port 8899 --poll-for-new-genesis-block --entrypoint testnet.solana.com +``` + +If you built from source: + +```bash +$ NDEBUG=1 USE_INSTALL=1 ./multinode-demo/validator.sh --identity ~/validator-keypair.json --voting-keypair ~/validator-vote-keypair.json --rpc-port 8899 --poll-for-new-genesis-block --entrypoint testnet.solana.com +``` + +### Enabling CUDA + +By default CUDA is disabled. If your machine has a GPU with CUDA installed, define the SOLANA\_CUDA flag in your environment _before_ running any of the previusly mentioned commands + +```bash +$ export SOLANA_CUDA=1 +``` + +When your validator is started look for the following log message to indicate that CUDA is enabled: `"[ solana::validator] CUDA is enabled"` + +### Controlling local network port allocation + +By default the validator will dynamically select available network ports in the 8000-10000 range, and may be overridden with `--dynamic-port-range`. For example, `validator.sh --dynamic-port-range 11000-11010 ...` will restrict the validator to ports 11000-11011. + +### Limiting ledger size to conserve disk space + +By default the validator will retain the full ledger. To conserve disk space start the validator with the `--limit-ledger-size`, which will instruct the validator to only retain the last couple hours of ledger. + diff --git a/book/src/running-validator/validator-testnet.md b/book/src/running-validator/validator-testnet.md new file mode 100644 index 0000000000..10fcb795bf --- /dev/null +++ b/book/src/running-validator/validator-testnet.md @@ -0,0 +1,74 @@ +# Choosing a Testnet + +As noted in the overview, solana currently maintains several testnets, each featuring a validator that can serve as the entrypoint to the cluster for your validator. + +Current testnet entrypoints: + +* Stable, testnet.solana.com +* Beta, beta.testnet.solana.com +* Edge, edge.testnet.solana.com + +Prior to mainnet, the testnets may be running different versions of solana software, which may feature breaking changes. Generally, the edge testnet tracks the tip of master, beta tracks the latest tagged minor release, and stable tracks the most stable tagged release. + +### Get Testnet Version + +You can submit a JSON-RPC request to see the specific version of the cluster. + +```bash +$ curl -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1, "method":"getVersion"}' edge.testnet.solana.com:8899 +{"jsonrpc":"2.0","result":{"solana-core":"0.18.0-pre1"},"id":1} +``` + +## Using a Different Testnet + +This guide is written in the context of testnet.solana.com, our most stable cluster. To participate in another testnet, you will need to modify some of the commands in the following pages. + +### Downloading Software + +If you are bootstrapping with `solana-install`, you can specify the release tag or named channel to install to match your desired testnet. + +```bash +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.1/install/solana-install-init.sh | sh -s - 0.18.1 +``` + +```bash +$ curl -sSf https://raw.githubusercontent.com/solana-labs/solana/v0.18.1/install/solana-install-init.sh | sh -s - beta +``` + +Similarly, you can add this argument to the `solana-install` command if you've built the program from source: + +```bash +$ solana-install init 0.18.1 +``` + +If you are downloading pre-compiled binaries or building from source, simply choose the release matching your desired testnet. + +### Validator Commands + +Solana CLI tools like solana and solana-validator-info point at testnet.solana.com by default. Include a `--url` argument to point at a different testnet. For instance: + +```bash +$ solana --url http://beta.testnet.solana.com:8899 balance +``` + +The solana cli includes `get` and `set` configuration commands to automatically set the `--url` argument for future wallet commands. For example: + +```bash +$ solana set --url http://beta.testnet.solana.com:8899 +$ solana balance # Same result as command above +``` + +\(You can always override the set configuration by explicitly passing the `--url` argument with a command.\) + +Solana-gossip and solana-validator commands already require an explicit `--entrypoint` argument. Simply replace testnet.solana.com in the examples with an alternate url to interact with a different testnet. For example: + +```bash +$ validator.sh --identity ~/validator-keypair.json --voting-keypair ~/validator-vote-keypair.json --ledger ~/validator-config --rpc-port 8899 --poll-for-new-genesis-block beta.testnet.solana.com +``` + +You can also submit JSON-RPC requests to a different testnet, like: + +```bash +$ curl -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1, "method":"getTransactionCount"}' http://beta.testnet.solana.com:8899 +``` + diff --git a/book/src/running-validator/validator-troubleshoot.md b/book/src/running-validator/validator-troubleshoot.md new file mode 100644 index 0000000000..1b66497ce8 --- /dev/null +++ b/book/src/running-validator/validator-troubleshoot.md @@ -0,0 +1,4 @@ +# Troubleshooting + +Coming soon... + diff --git a/book/src/terminology.md b/book/src/terminology.md index 7f9b50cc7b..8d59adb7bb 100644 --- a/book/src/terminology.md +++ b/book/src/terminology.md @@ -2,361 +2,291 @@ The following terms are used throughout this book. -#### account +## account -A persistent file addressed by [public key](#public-key) and with -[lamports](#lamport) tracking its lifetime. +A persistent file addressed by [public key](terminology.md#public-key) and with [lamports](terminology.md#lamport) tracking its lifetime. -#### app +## app A front-end application that interacts with a Solana cluster. -#### block +## blob -A contiguous set of [entries](#entry) on the ledger covered by a -[vote](#ledger-vote). A [leader](#leader) produces at most one block per -[slot](#slot). +A fraction of a [block](terminology.md#block); the smallest unit sent between [fullnodes](terminology.md#fullnode). -#### block height +## block -The number of [blocks](#block) beneath the current block. The first block after -the [genesis block](#genesis-block) has height zero. +A contiguous set of [entries](terminology.md#entry) on the ledger covered by a [vote](terminology.md#ledger-vote). A [leader](terminology.md#leader) produces at most one block per [slot](terminology.md#slot). -#### block id +## block height -The [entry id](#entry-id) of the last entry in a [block](#block). +The number of [blocks](terminology.md#block) beneath the current block. The first block after the [genesis block](terminology.md#genesis-block) has height zero. -#### bootstrap leader +## block id -The first [fullnode](#fullnode) to take the [leader](#leader) role. +The [entry id](terminology.md#entry-id) of the last entry in a [block](terminology.md#block). -#### CBC block +## bootstrap leader -Smallest encrypted chunk of ledger, an encrypted ledger segment would be made of -many CBC blocks. `ledger_segment_size / cbc_block_size` to be exact. +The first [fullnode](terminology.md#fullnode) to take the [leader](terminology.md#leader) role. -#### client +## CBC block -A [node](#node) that utilizes the [cluster](#cluster). +Smallest encrypted chunk of ledger, an encrypted ledger segment would be made of many CBC blocks. `ledger_segment_size / cbc_block_size` to be exact. -#### cluster +## client -A set of [fullnodes](#fullnode) maintaining a single [ledger](#ledger). +A [node](terminology.md#node) that utilizes the [cluster](terminology.md#cluster). -#### confirmation +## cluster -The wallclock duration between a [leader](#leader) creating a [tick -entry](#tick) and recognizing a supermajority of [ledger votes](#ledger-vote) -with a ledger interpretation that matches the leader's. +A set of [fullnodes](terminology.md#fullnode) maintaining a single [ledger](terminology.md#ledger). -#### control plane +## confirmation -A gossip network connecting all [nodes](#node) of a [cluster](#cluster). +The wallclock duration between a [leader](terminology.md#leader) creating a [tick entry](terminology.md#tick) and recognizing a supermajority of [ledger votes](terminology.md#ledger-vote) with a ledger interpretation that matches the leader's. -#### cooldown period +## control plane -Some number of epochs after stake has been deactivated while it progressively -becomes available for withdrawal. During this period, the stake is considered to -be "deactivating". More info about: -[warmup and cooldown](stake-delegation-and-rewards.md#stake-warmup-cooldown-withdrawal) +A gossip network connecting all [nodes](terminology.md#node) of a [cluster](terminology.md#cluster). -#### credit +## cooldown period -See [vote credit](#vote-credit). +Some number of epochs after stake has been deactivated while it progressively becomes available for withdrawal. During this period, the stake is considered to be "deactivating". More info about: [warmup and cooldown](cluster/stake-delegation-and-rewards.md#stake-warmup-cooldown-withdrawal) -#### data plane +## credit -A multicast network used to efficiently validate [entries](#entry) and gain -consensus. +See [vote credit](terminology.md#vote-credit). -#### drone +## data plane -An off-chain service that acts as a custodian for a user's private key. It -typically serves to validate and sign transactions. +A multicast network used to efficiently validate [entries](terminology.md#entry) and gain consensus. -#### entry +## drone -An entry on the [ledger](#ledger) either a [tick](#tick) or a [transactions -entry](#transactions-entry). +An off-chain service that acts as a custodian for a user's private key. It typically serves to validate and sign transactions. -#### entry id +## fake storage proof -A globally unique identifier that is also a proof that the [entry](#entry) was -generated after a duration of time, all [transactions](#transaction) included -in the entry, and all previous entries on the [ledger](#ledger). See [Proof of -History](#proof-of-history). +A proof which has the same format as a storage proof, but the sha state is actually from hashing a known ledger value which the storage client can reveal and is also easily verifiable by the network on-chain. -#### epoch +## entry -The time, i.e. number of [slots](#slot), for which a [leader -schedule](#leader-schedule) is valid. +An entry on the [ledger](terminology.md#ledger) either a [tick](terminology.md#tick) or a [transactions entry](terminology.md#transactions-entry). -#### fake storage proof +## entry id -A proof which has the same format as a storage proof, but the sha state is -actually from hashing a known ledger value which the storage client can reveal -and is also easily verifiable by the network on-chain. +A globally unique identifier that is also a proof that the [entry](terminology.md#entry) was generated after a duration of time, all [transactions](terminology.md#transaction) included in the entry, and all previous entries on the [ledger](terminology.md#ledger). See [Proof of History](terminology.md#proof-of-history). -#### finality +## epoch -When nodes representing 2/3rd of the stake have a common [root](#root). +The time, i.e. number of [slots](terminology.md#slot), for which a [leader schedule](terminology.md#leader-schedule) is valid. -#### fork +## finality -A [ledger](#ledger) derived from common entries but then diverged. +When nodes representing 2/3rd of the stake have a common [root](terminology.md#root). -#### fullnode +## fork -A full participant in the [cluster](#cluster) either a [leader](#leader) or -[validator](#validator) node. +A [ledger](terminology.md#ledger) derived from common entries but then diverged. -#### fullnode state +## fullnode -The result of interpreting all programs on the ledger at a given [tick -height](#tick-height). It includes at least the set of all [accounts](#account) -holding nonzero [native tokens](#native-tokens). +A full participant in the [cluster](terminology.md#cluster) either a [leader](terminology.md#leader) or [validator](terminology.md#validator) node. -#### genesis block +## fullnode state -The configuration file that prepares the [ledger](#ledger) for the first [block](#block). +The result of interpreting all programs on the ledger at a given [tick height](terminology.md#tick-height). It includes at least the set of all [accounts](terminology.md#account) holding nonzero [native tokens](terminology.md#native-tokens). -#### hash +## genesis block + +The configuration file that prepares the [ledger](terminology.md#ledger) for the first [block](terminology.md#block). + +## hash A digital fingerprint of a sequence of bytes. -#### instruction +## instruction -The smallest unit of a [program](#program) that a [client](#client) can include -in a [transaction](#instruction). +The smallest unit of a [program](terminology.md#program) that a [client](terminology.md#client) can include in a [transaction](terminology.md#instruction). -#### keypair +## keypair -A [public key](#public-key) and corresponding [private key](#private-key). +A [public key](terminology.md#public-key) and corresponding [secret key](terminology.md#secret-key). -#### lamport +## lamport -A fractional [native token](#native-token) with the value of approximately -0.0000000000582 [sol](#sol) (2^-34). +A fractional [native token](terminology.md#native-token) with the value of approximately 0.0000000000582 [sol](terminology.md#sol) \(2^-34\). -#### loader +## loader -A [program](#program) with the ability to interpret the binary encoding of -other on-chain programs. +A [program](terminology.md#program) with the ability to interpret the binary encoding of other on-chain programs. -#### leader +## leader -The role of a [fullnode](#fullnode) when it is appending [entries](#entry) to -the [ledger](#ledger). +The role of a [fullnode](terminology.md#fullnode) when it is appending [entries](terminology.md#entry) to the [ledger](terminology.md#ledger). -#### leader schedule +## leader schedule -A sequence of [fullnode](#fullnode) [public keys](#public-key). The cluster -uses the leader schedule to determine which fullnode is the [leader](#leader) -at any moment in time. +A sequence of [fullnode](terminology.md#fullnode) [public keys](terminology.md#public-key). The cluster uses the leader schedule to determine which fullnode is the [leader](terminology.md#leader) at any moment in time. -#### ledger +## ledger -A list of [entries](#entry) containing [transactions](#transaction) signed by -[clients](#client). +A list of [entries](terminology.md#entry) containing [transactions](terminology.md#transaction) signed by [clients](terminology.md#client). -#### ledger segment +## ledger segment -Portion of the ledger which is downloaded by the replicator where storage proof -data is derived. +Portion of the ledger which is downloaded by the replicator where storage proof data is derived. -#### ledger vote +## ledger vote -A [hash](#hash) of the [fullnode's state](#fullnode-state) at a given [tick -height](#tick-height). It comprises a validator's affirmation that a -[block](#block) it has received has been verified, as well as a promise not to -vote for a conflicting [block](#block) (i.e. [fork](#fork)) for a specific -amount of time, the [lockout](#lockout) period. +A [hash](terminology.md#hash) of the [fullnode's state](terminology.md#fullnode-state) at a given [tick height](terminology.md#tick-height). It comprises a validator's affirmation that a [block](terminology.md#block) it has received has been verified, as well as a promise not to vote for a conflicting [block](terminology.md#block) \(i.e. [fork](terminology.md#fork)\) for a specific amount of time, the [lockout](terminology.md#lockout) period. -#### light client +## light client -A type of [client](#client) that can verify it's pointing to a valid -[cluster](#cluster). It performs more ledger verification than a [thin -client](#thin-client) and less than a [fullnode](#fullnode). +A type of [client](terminology.md#client) that can verify it's pointing to a valid [cluster](terminology.md#cluster). It performs more ledger verification than a [thin client](terminology.md#thin-client) and less than a [fullnode](terminology.md#fullnode). -#### lockout +## lockout -The duration of time for which a [fullnode](#fullnode) is unable to -[vote](#ledger-vote) on another [fork](#fork). +The duration of time for which a [fullnode](terminology.md#fullnode) is unable to [vote](terminology.md#ledger-vote) on another [fork](terminology.md#fork). -#### native token +## native token -The [token](#token) used to track work done by [nodes](#node) in a cluster. +The [token](terminology.md#token) used to track work done by [nodes](terminology.md#node) in a cluster. -#### node +## node -A computer participating in a [cluster](#cluster). +A computer participating in a [cluster](terminology.md#cluster). -#### node count +## node count -The number of [fullnodes](#fullnode) participating in a [cluster](#cluster). +The number of [fullnodes](terminology.md#fullnode) participating in a [cluster](terminology.md#cluster). -#### PoH +## PoH -See [Proof of History](#proof-of-history). +See [Proof of History](terminology.md#proof-of-history). -#### point +## point -A weighted [credit](#credit) in a rewards regime. In the validator [rewards regime](staking-rewards.md), the number of points owed to a stake during redemption is the product of the [vote credits](#vote-credit) earned and the number of lamports staked. +A weighted [credit](terminology.md#credit) in a rewards regime. In the validator [rewards regime](proposals/staking-rewards.md), the number of points owed to a stake during redemption is the product of the [vote credits](terminology.md#vote-credit) earned and the number of lamports staked. -#### private key +## program -The private key of a [keypair](#keypair). +The code that interprets [instructions](terminology.md#instruction). -#### program +## program id -The code that interprets [instructions](#instruction). +The public key of the [account](terminology.md#account) containing a [program](terminology.md#program). -#### program id +## Proof of History -The public key of the [account](#account) containing a [program](#program). +A stack of proofs, each which proves that some data existed before the proof was created and that a precise duration of time passed before the previous proof. Like a [VDF](terminology.md#verifiable-delay-function), a Proof of History can be verified in less time than it took to produce. -#### Proof of History +## public key -A stack of proofs, each which proves that some data existed before the proof -was created and that a precise duration of time passed before the previous -proof. Like a [VDF](#verifiable-delay-function), a Proof of History can be -verified in less time than it took to produce. +The public key of a [keypair](terminology.md#keypair). -#### public key +## replicator -The public key of a [keypair](#keypair). +Storage mining client, stores some part of the ledger enumerated in blocks and submits storage proofs to the chain. Not a full-node. -#### replicator +## root -Storage mining client, stores some part of the ledger enumerated in blocks and -submits storage proofs to the chain. Not a full-node. +A [block](terminology.md#block) or [slot](terminology.md#slot) that has reached maximum [lockout](terminology.md#lockout) on a validator. The root is the highest block that is an ancestor of all active forks on a validator. All ancestor blocks of a root are also transitively a root. Blocks that are not an ancestor and not a descendant of the root are excluded from consideration for consensus and can be discarded. -#### root +## runtime -A [block](#block) or [slot](#slot) that has reached maximum [lockout](#lockout) -on a validator. The root is the highest block that is an ancestor of all active -forks on a validator. All ancestor blocks of a root are also transitively a -root. Blocks that are not an ancestor and not a descendant of the root are -excluded from consideration for consensus and can be discarded. +The component of a [fullnode](terminology.md#fullnode) responsible for [program](terminology.md#program) execution. +## secret key -#### runtime +The private key of a [keypair](terminology.md#keypair). -The component of a [fullnode](#fullnode) responsible for [program](#program) -execution. +## slot -#### shred +The period of time for which a [leader](terminology.md#leader) ingests transactions and produces a [block](terminology.md#block). -A fraction of a [block](#block); the smallest unit sent between -[fullnodes](#fullnode). +## sol -#### slot +The [native token](terminology.md#native-token) tracked by a [cluster](terminology.md#cluster) recognized by the company Solana. -The period of time for which a [leader](#leader) ingests transactions and -produces a [block](#block). +## stake -#### smart contract +Tokens forfeit to the [cluster](terminology.md#cluster) if malicious [fullnode](terminology.md#fullnode) behavior can be proven. -A set of constraints that once satisfied, signal to a program that some -predefined account updates are permitted. +## storage proof -#### sol +A set of sha hash state which is constructed by sampling the encrypted version of the stored ledger segment at certain offsets. -The [native token](#native-token) tracked by a [cluster](#cluster) recognized -by the company Solana. +## storage proof challenge -#### stake +A transaction from a replicator that verifiably proves that a validator confirmed a fake proof. -Tokens forfeit to the [cluster](#cluster) if malicious [fullnode](#fullnode) -behavior can be proven. +## storage proof claim -#### storage proof +A transaction from a validator which is after the timeout period given from the storage proof confirmation and which no successful challenges have been observed which rewards the parties of the storage proofs and confirmations. -A set of sha hash state which is constructed by sampling the encrypted version -of the stored ledger segment at certain offsets. +## storage proof confirmation -#### storage proof challenge +A transaction by a validator which indicates the set of real and fake proofs submitted by a storage miner. The transaction would contain a list of proof hash values and a bit which says if this hash is valid or fake. -A transaction from a replicator that verifiably proves that a validator -confirmed a fake proof. - -#### storage proof claim - -A transaction from a validator which is after the timeout period given from the -storage proof confirmation and which no successful challenges have been -observed which rewards the parties of the storage proofs and confirmations. - -#### storage proof confirmation - -A transaction by a validator which indicates the set of real and fake proofs -submitted by a storage miner. The transaction would contain a list of proof -hash values and a bit which says if this hash is valid or fake. - -#### storage validation capacity +## storage validation capacity The number of keys and samples that a validator can verify each storage epoch. -#### sysvar +## sysvar -A synthetic [account](#account) provided by the runtime to allow programs to -access network state such as current tick height, rewards [points](#point) values, etc. +A synthetic [account](terminology.md#account) provided by the runtime to allow programs to access network state such as current tick height, rewards [points](terminology.md#point) values, etc. -#### thin client +## thin client -A type of [client](#client) that trusts it is communicating with a valid -[cluster](#cluster). +A type of [client](terminology.md#client) that trusts it is communicating with a valid [cluster](terminology.md#cluster). -#### tick +## tick -A ledger [entry](#entry) that estimates wallclock duration. +A ledger [entry](terminology.md#entry) that estimates wallclock duration. -#### tick height +## tick height -The Nth [tick](#tick) in the [ledger](#ledger). +The Nth [tick](terminology.md#tick) in the [ledger](terminology.md#ledger). -#### token +## token A scarce, fungible member of a set of tokens. -#### tps +## tps -[Transactions](#transaction) per second. +[Transactions](terminology.md#transaction) per second. -#### transaction +## transaction -One or more [instructions](#instruction) signed by the [client](#client) and -executed atomically. +One or more [instructions](terminology.md#instruction) signed by the [client](terminology.md#client) and executed atomically. -#### transactions entry +## transactions entry -A set of [transactions](#transaction) that may be executed in parallel. +A set of [transactions](terminology.md#transaction) that may be executed in parallel. -#### validator +## validator -The role of a [fullnode](#fullnode) when it is validating the -[leader's](#leader) latest [entries](#entry). +The role of a [fullnode](terminology.md#fullnode) when it is validating the [leader's](terminology.md#leader) latest [entries](terminology.md#entry). -#### VDF +## VDF -See [verifiable delay function](#verifiable-delay-function). +See [verifiable delay function](terminology.md#verifiable-delay-function). -#### verifiable delay function +## verifiable delay function -A function that takes a fixed amount of time to execute that produces a proof -that it ran, which can then be verified in less time than it took to produce. +A function that takes a fixed amount of time to execute that produces a proof that it ran, which can then be verified in less time than it took to produce. -#### vote +## vote -See [ledger vote](#ledger-vote). +See [ledger vote](terminology.md#ledger-vote). -#### vote credit +## vote credit -A reward tally for validators. A vote credit is awarded to a validator in its -vote account when the validator reaches a [root](#root). +A reward tally for validators. A vote credit is awarded to a validator in its vote account when the validator reaches a [root](terminology.md#root). -#### warmup period +## warmup period + +Some number of epochs after stake has been delegated while it progressively becomes effective. During this period, the stake is considered to be "activating". More info about: [warmup and cooldown](cluster/stake-delegation-and-rewards.md#stake-warmup-cooldown-withdrawal) -Some number of epochs after stake has been delegated while it progressively -becomes effective. During this period, the stake is considered to be -"activating". More info about: -[warmup and cooldown](stake-delegation-and-rewards.md#stake-warmup-cooldown-withdrawal) diff --git a/book/src/transaction.md b/book/src/transaction.md index 51c41fe319..f2535a8f09 100644 --- a/book/src/transaction.md +++ b/book/src/transaction.md @@ -1,41 +1,16 @@ # Anatomy of a Transaction -Transactions encode lists of instructions that are executed -sequentially, and only committed if all the instructions complete -successfully. All account updates are reverted upon the failure of a -transaction. Each transaction details the accounts used, including which -must sign and which are credit only, a recent blockhash, the -instructions, and any signatures. +Transactions encode lists of instructions that are executed sequentially, and only committed if all the instructions complete successfully. All account states are reverted upon the failure of a transaction. Each Transaction details the accounts used, including which must sign and which are credit only, a recent blockhash, the instructions, and any signatures. ## Accounts and Signatures -Each transaction explicitly lists all account public keys referenced by the -transaction's instructions. A subset of those public keys are each accompanied -by a transaction signature. Those signatures signal on-chain programs that -the account holder has authorized the transaction. Typically, the program -uses the authorization to permit debiting the account or modifying its -data. - -The transaction also marks some accounts as *credit-only accounts*. The -runtime permits credit-only accounts to be credited concurrently. If a -program attempts to debit a credit-only account or modify its account -data, the transaction is rejected by the runtime. +Each transaction explicitly lists all accounts that it needs access to. This includes accounts that are transferring tokens, accounts whose user data is being modified, and the program accounts that are being called by the instructions. Each account that is not an executable program can be marked as a requiring a signature and/or as credit only. All accounts marked as signers must have a valid signature in the transaction's list of signatures before the transaction is considered valid. Any accounts marked as credit only may only have their token value increased, and their user data is read only. Accounts are locked by the runtime, ensuring that they are not modified by a concurrent program while the transaction is running. Credit only accounts can safely be shared, so the runtime will allow multiple concurrent credit only locks on an account. ## Recent Blockhash -A Transaction includes a recent blockhash to prevent duplication and to -give transactions lifetimes. Any transaction that is completely -identical to a previous one is rejected, so adding a newer blockhash -allows multiple transactions to repeat the exact same action. -Transactions also have lifetimes that are defined by the blockhash, as -any transaction whose blockhash is too old will be rejected. +A Transaction includes a recent blockhash to prevent duplication and to give transactions lifetimes. Any transaction that is completely identical to a previous one is rejected, so adding a newer blockhash allows multiple transactions to repeat the exact same action. Transactions also have lifetimes that are defined by the blockhash, as any transaction whose blockhash is too old will be rejected. ## Instructions -Each instruction specifies a single program account (which must be -marked executable), a subset of the transaction's accounts that should -be passed to the program, and a data byte array instruction that is -passed to the program. The program interprets the data array and -operates on the accounts specified by the instructions. The program can -return successfully, or with an error code. An error return causes the -entire transaction to fail immediately. +Each instruction specifies a single program account \(which must be marked executable\), a subset of the transaction's accounts that should be passed to the program, and a data byte array instruction that is passed to the program. The program interprets the data array and operates on the accounts specified by the instructions. The program can return successfully, or with an error code. An error return causes the entire transaction to fail immediately. + diff --git a/book/src/validator/README.md b/book/src/validator/README.md new file mode 100644 index 0000000000..add49f3c75 --- /dev/null +++ b/book/src/validator/README.md @@ -0,0 +1,12 @@ +# Anatomy of a Validator + +![Validator block diagrams](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/validator.svg) + +## Pipelining + +The validators make extensive use of an optimization common in CPU design, called _pipelining_. Pipelining is the right tool for the job when there's a stream of input data that needs to be processed by a sequence of steps, and there's different hardware responsible for each. The quintessential example is using a washer and dryer to wash/dry/fold several loads of laundry. Washing must occur before drying and drying before folding, but each of the three operations is performed by a separate unit. To maximize efficiency, one creates a pipeline of _stages_. We'll call the washer one stage, the dryer another, and the folding process a third. To run the pipeline, one adds a second load of laundry to the washer just after the first load is added to the dryer. Likewise, the third load is added to the washer after the second is in the dryer and the first is being folded. In this way, one can make progress on three loads of laundry simultaneously. Given infinite loads, the pipeline will consistently complete a load at the rate of the slowest stage in the pipeline. + +## Pipelining in the Validator + +The validator contains two pipelined processes, one used in leader mode called the TPU and one used in validator mode called the TVU. In both cases, the hardware being pipelined is the same, the network input, the GPU cards, the CPU cores, writes to disk, and the network output. What it does with that hardware is different. The TPU exists to create ledger entries whereas the TVU exists to validate them. + diff --git a/book/src/validator/gossip.md b/book/src/validator/gossip.md new file mode 100644 index 0000000000..e4b9576cf9 --- /dev/null +++ b/book/src/validator/gossip.md @@ -0,0 +1,89 @@ +# Gossip Service + +The Gossip Service acts as a gateway to nodes in the control plane. Validators use the service to ensure information is available to all other nodes in a cluster. The service broadcasts information using a gossip protocol. + +## Gossip Overview + +Nodes continuously share signed data objects among themselves in order to manage a cluster. For example, they share their contact information, ledger height, and votes. + +Every tenth of a second, each node sends a "push" message and/or a "pull" message. Push and pull messages may elicit responses, and push messages may be forwarded on to others in the cluster. + +Gossip runs on a well-known UDP/IP port or a port in a well-known range. Once a cluster is bootstrapped, nodes advertise to each other where to find their gossip endpoint \(a socket address\). + +## Gossip Records + +Records shared over gossip are arbitrary, but signed and versioned \(with a timestamp\) as needed to make sense to the node receiving them. If a node receives two records from the same source, it updates its own copy with the record with the most recent timestamp. + +## Gossip Service Interface + +### Push Message + +A node sends a push message to tells the cluster it has information to share. Nodes send push messages to `PUSH_FANOUT` push peers. + +Upon receiving a push message, a node examines the message for: + +1. Duplication: if the message has been seen before, the node drops the message and may respond with `PushMessagePrune` if forwarded from a low staked node +2. New data: if the message is new to the node + * Stores the new information with an updated version in its cluster info and + + purges any previous older value + + * Stores the message in `pushed_once` \(used for detecting duplicates, + + purged after `PUSH_MSG_TIMEOUT * 5` ms\) + + * Retransmits the messages to its own push peers +3. Expiration: nodes drop push messages that are older than `PUSH_MSG_TIMEOUT` + +### Push Peers, Prune Message + +A nodes selects its push peers at random from the active set of known peers. The node keeps this selection for a relatively long time. When a prune message is received, the node drops the push peer that sent the prune. Prune is an indication that there is another, higher stake weighted path to that node than direct push. + +The set of push peers is kept fresh by rotating a new node into the set every `PUSH_MSG_TIMEOUT/2` milliseconds. + +### Pull Message + +A node sends a pull message to ask the cluster if there is any new information. A pull message is sent to a single peer at random and comprises a Bloom filter that represents things it already has. A node receiving a pull message iterates over its values and constructs a pull response of things that miss the filter and would fit in a message. + +A node constructs the pull Bloom filter by iterating over current values and recently purged values. + +A node handles items in a pull response the same way it handles new data in a push message. + +## Purging + +Nodes retain prior versions of values \(those updated by a pull or push\) and expired values \(those older than `GOSSIP_PULL_CRDS_TIMEOUT_MS`\) in `purged_values` \(things I recently had\). Nodes purge `purged_values` that are older than `5 * GOSSIP_PULL_CRDS_TIMEOUT_MS`. + +## Eclipse Attacks + +An eclipse attack is an attempt to take over the set of node connections with adversarial endpoints. + +This is relevant to our implementation in the following ways. + +* Pull messages select a random node from the network. An eclipse attack on _pull_ would require an attacker to influence the random selection in such a way that only adversarial nodes are selected for pull. +* Push messages maintain an active set of nodes and select a random fanout for every push message. An eclipse attack on _push_ would influence the active set selection, or the random fanout selection. + +### Time and Stake based weights + +Weights are calculated based on `time since last picked` and the `natural log` of the `stake weight`. + +Taking the `ln` of the stake weight allows giving all nodes a fairer chance of network coverage in a reasonable amount of time. It helps normalize the large possible `stake weight` differences between nodes. This way a node with low `stake weight`, compared to a node with large `stake weight` will only have to wait a few multiples of ln\(`stake`\) seconds before it gets picked. + +There is no way for an adversary to influence these parameters. + +### Pull Message + +A node is selected as a pull target based on the weights described above. + +### Push Message + +A prune message can only remove an adversary from a potential connection. + +Just like _pull message_, nodes are selected into the active set based on weights. + +## Notable differences from PlumTree + +The active push protocol described here is based on [Plum Tree](https://haslab.uminho.pt/jop/files/lpr07a.pdf). The main differences are: + +* Push messages have a wallclock that is signed by the originator. Once the wallclock expires the message is dropped. A hop limit is difficult to implement in an adversarial setting. +* Lazy Push is not implemented because its not obvious how to prevent an adversary from forging the message fingerprint. A naive approach would allow an adversary to be prioritized for pull based on their input. + diff --git a/book/src/validator/runtime.md b/book/src/validator/runtime.md new file mode 100644 index 0000000000..d1747f54d6 --- /dev/null +++ b/book/src/validator/runtime.md @@ -0,0 +1,65 @@ +# The Runtime + +## The Runtime + +The runtime is a concurrent transaction processor. Transactions specify their data dependencies upfront and dynamic memory allocation is explicit. By separating program code from the state it operates on, the runtime is able to choreograph concurrent access. Transactions accessing only credit-only accounts are executed in parallel whereas transactions accessing writable accounts are serialized. The runtime interacts with the program through an entrypoint with a well-defined interface. The data stored in an account is an opaque type, an array of bytes. The program has full control over its contents. + +The transaction structure specifies a list of public keys and signatures for those keys and a sequential list of instructions that will operate over the states associated with the account keys. For the transaction to be committed all the instructions must execute successfully; if any abort the whole transaction fails to commit. + +#### Account Structure + +Accounts maintain a lamport balance and program-specific memory. + +## Transaction Engine + +The engine maps public keys to accounts and routes them to the program's entrypoint. + +### Execution + +Transactions are batched and processed in a pipeline. The TPU and TVU follow a slightly different path. The TPU runtime ensures that PoH record occurs before memory is committed. + +The TVU runtime ensures that PoH verification occurs before the runtime processes any transactions. + +![Runtime pipeline](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/runtime.svg) + +At the _execute_ stage, the loaded accounts have no data dependencies, so all the programs can be executed in parallel. + +The runtime enforces the following rules: + +1. Only the _owner_ program may modify the contents of an account. This means that upon assignment data vector is guaranteed to be zero. +2. Total balances on all the accounts is equal before and after execution of a transaction. +3. After the transaction is executed, balances of credit-only accounts must be greater than or equal to the balances before the transaction. +4. All instructions in the transaction executed atomically. If one fails, all account modifications are discarded. + +Execution of the program involves mapping the program's public key to an entrypoint which takes a pointer to the transaction, and an array of loaded accounts. + +### SystemProgram Interface + +The interface is best described by the `Instruction::data` that the user encodes. + +* `CreateAccount` - This allows the user to create an account with an allocated data array and assign it to a Program. +* `Assign` - Allows the user to assign an existing account to a program. +* `Transfer` - Transfers lamports between accounts. + +### Program State Security + +For blockchain to function correctly, the program code must be resilient to user inputs. That is why in this design the program specific code is the only code that can change the state of the data byte array in the Accounts that are assigned to it. It is also the reason why `Assign` or `CreateAccount` must zero out the data. Otherwise there would be no possible way for the program to distinguish the recently assigned account data from a natively generated state transition without some additional metadata from the runtime to indicate that this memory is assigned instead of natively generated. + +To pass messages between programs, the receiving program must accept the message and copy the state over. But in practice a copy isn't needed and is undesirable. The receiving program can read the state belonging to other Accounts without copying it, and during the read it has a guarantee of the sender program's state. + +### Notes + +* There is no dynamic memory allocation. Client's need to use `CreateAccount` instructions to create memory before passing it to another program. This instruction can be composed into a single transaction with the call to the program itself. +* `CreateAccount` and `Assign` guarantee that when account is assigned to the program, the Account's data is zero initialized. +* Once assigned to program an Account cannot be reassigned. +* Runtime guarantees that a program's code is the only code that can modify Account data that the Account is assigned to. +* Runtime guarantees that the program can only spend lamports that are in accounts that are assigned to it. +* Runtime guarantees the balances belonging to accounts are balanced before and after the transaction. +* Runtime guarantees that instructions all executed successfully when a transaction is committed. + +## Future Work + +* \[Continuations and Signals for long running + + Transactions\]\([https://github.com/solana-labs/solana/issues/1485](https://github.com/solana-labs/solana/issues/1485)\) + diff --git a/book/src/validator/tpu.md b/book/src/validator/tpu.md new file mode 100644 index 0000000000..fef55db7b3 --- /dev/null +++ b/book/src/validator/tpu.md @@ -0,0 +1,4 @@ +# TPU + +![TPU Block Diagram](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/tpu.svg) + diff --git a/book/src/validator/tvu/README.md b/book/src/validator/tvu/README.md new file mode 100644 index 0000000000..15394008c3 --- /dev/null +++ b/book/src/validator/tvu/README.md @@ -0,0 +1,4 @@ +# TVU + +![TVU Block Diagram](https://github.com/solana-labs/solana/tree/6b18db969dd1616eff07de35e7b823c75339fea8/book/src/img/tvu.svg) + diff --git a/book/src/validator/tvu/blocktree.md b/book/src/validator/tvu/blocktree.md new file mode 100644 index 0000000000..2574532cec --- /dev/null +++ b/book/src/validator/tvu/blocktree.md @@ -0,0 +1,93 @@ +# Blocktree + +After a block reaches finality, all blocks from that one on down to the genesis block form a linear chain with the familiar name blockchain. Until that point, however, the validator must maintain all potentially valid chains, called _forks_. The process by which forks naturally form as a result of leader rotation is described in [fork generation](../../cluster/fork-generation.md). The _blocktree_ data structure described here is how a validator copes with those forks until blocks are finalized. + +The blocktree allows a validator to record every blob it observes on the network, in any order, as long as the blob is signed by the expected leader for a given slot. + +Blobs are moved to a fork-able key space the tuple of `leader slot` + `blob index` \(within the slot\). This permits the skip-list structure of the Solana protocol to be stored in its entirety, without a-priori choosing which fork to follow, which Entries to persist or when to persist them. + +Repair requests for recent blobs are served out of RAM or recent files and out of deeper storage for less recent blobs, as implemented by the store backing Blocktree. + +## Functionalities of Blocktree + +1. Persistence: the Blocktree lives in the front of the nodes verification + + pipeline, right behind network receive and signature verification. If the + + blob received is consistent with the leader schedule \(i.e. was signed by the + + leader for the indicated slot\), it is immediately stored. + +2. Repair: repair is the same as window repair above, but able to serve any + + blob that's been received. Blocktree stores blobs with signatures, + + preserving the chain of origination. + +3. Forks: Blocktree supports random access of blobs, so can support a + + validator's need to rollback and replay from a Bank checkpoint. + +4. Restart: with proper pruning/culling, the Blocktree can be replayed by + + ordered enumeration of entries from slot 0. The logic of the replay stage + + \(i.e. dealing with forks\) will have to be used for the most recent entries in + + the Blocktree. + +## Blocktree Design + +1. Entries in the Blocktree are stored as key-value pairs, where the key is the concatenated slot index and blob index for an entry, and the value is the entry data. Note blob indexes are zero-based for each slot \(i.e. they're slot-relative\). +2. The Blocktree maintains metadata for each slot, in the `SlotMeta` struct containing: + * `slot_index` - The index of this slot + * `num_blocks` - The number of blocks in the slot \(used for chaining to a previous slot\) + * `consumed` - The highest blob index `n`, such that for all `m < n`, there exists a blob in this slot with blob index equal to `n` \(i.e. the highest consecutive blob index\). + * `received` - The highest received blob index for the slot + * `next_slots` - A list of future slots this slot could chain to. Used when rebuilding + + the ledger to find possible fork points. + + * `last_index` - The index of the blob that is flagged as the last blob for this slot. This flag on a blob will be set by the leader for a slot when they are transmitting the last blob for a slot. + * `is_rooted` - True iff every block from 0...slot forms a full sequence without any holes. We can derive is\_rooted for each slot with the following rules. Let slot\(n\) be the slot with index `n`, and slot\(n\).is\_full\(\) is true if the slot with index `n` has all the ticks expected for that slot. Let is\_rooted\(n\) be the statement that "the slot\(n\).is\_rooted is true". Then: + + is\_rooted\(0\) is\_rooted\(n+1\) iff \(is\_rooted\(n\) and slot\(n\).is\_full\(\) +3. Chaining - When a blob for a new slot `x` arrives, we check the number of blocks \(`num_blocks`\) for that new slot \(this information is encoded in the blob\). We then know that this new slot chains to slot `x - num_blocks`. +4. Subscriptions - The Blocktree records a set of slots that have been "subscribed" to. This means entries that chain to these slots will be sent on the Blocktree channel for consumption by the ReplayStage. See the `Blocktree APIs` for details. +5. Update notifications - The Blocktree notifies listeners when slot\(n\).is\_rooted is flipped from false to true for any `n`. + +## Blocktree APIs + +The Blocktree offers a subscription based API that ReplayStage uses to ask for entries it's interested in. The entries will be sent on a channel exposed by the Blocktree. These subscription API's are as follows: 1. `fn get_slots_since(slot_indexes: &[u64]) -> Vec`: Returns new slots connecting to any element of the list `slot_indexes`. + +1. `fn get_slot_entries(slot_index: u64, entry_start_index: usize, max_entries: Option) -> Vec`: Returns the entry vector for the slot starting with `entry_start_index`, capping the result at `max` if `max_entries == Some(max)`, otherwise, no upper limit on the length of the return vector is imposed. + +Note: Cumulatively, this means that the replay stage will now have to know when a slot is finished, and subscribe to the next slot it's interested in to get the next set of entries. Previously, the burden of chaining slots fell on the Blocktree. + +## Interfacing with Bank + +The bank exposes to replay stage: + +1. `prev_hash`: which PoH chain it's working on as indicated by the hash of the last + + entry it processed + +2. `tick_height`: the ticks in the PoH chain currently being verified by this + + bank + +3. `votes`: a stack of records that contain: + 1. `prev_hashes`: what anything after this vote must chain to in PoH + 2. `tick_height`: the tick height at which this vote was cast + 3. `lockout period`: how long a chain must be observed to be in the ledger to + + be able to be chained below this vote + +Replay stage uses Blocktree APIs to find the longest chain of entries it can hang off a previous vote. If that chain of entries does not hang off the latest vote, the replay stage rolls back the bank to that vote and replays the chain from there. + +## Pruning Blocktree + +Once Blocktree entries are old enough, representing all the possible forks becomes less useful, perhaps even problematic for replay upon restart. Once a validator's votes have reached max lockout, however, any Blocktree contents that are not on the PoH chain for that vote for can be pruned, expunged. + +Replicator nodes will be responsible for storing really old ledger contents, and validators need only persist their bank periodically. +