Split signature throughput tracking out of FeeCalculator (#8447)

* SDK: Split new `FeeRateGovernor` out of `FeeCalculator`

Leaving `FeeCalculator` to *only* calculate transaction fees

* Replace `FeeCalculator` with `FeeRateGovernor` as appropriate

* Expose recent `FeeRateGovernor` to clients

* Move `burn()` back into `FeeCalculator`

Appease BPF tests

* Revert "Move `burn()` back into `FeeCalculator`"

This reverts commit f3035624307196722b62ff8b74c12cfcc13b1941.

* Adjust BPF `Fee` sysvar test to reflect removal of `burn()` from `FeeCalculator`

* Make `FeeRateGovernor`'s `lamports_per_signature` private

* rebase artifacts

* fmt

* Drop 'Recent'

* Drop _with_commitment variant

* Use a more portable integer for `target_signatures_per_slot`

* Add docs for `getReeRateCalculator` JSON RPC method

* Don't return `lamports_per_signature` in `getFeeRateGovernor` JSONRPC reply

bench-tps/src/bench.rs

@@ -1059,8 +1059,8 @@ pub fn generate_and_fund_keypairs<T: 'static + Client + Send + Sync>(
     //   pay for the transaction fees in a new run.
     let enough_lamports = 8 * lamports_per_account / 10;
     if first_keypair_balance < enough_lamports || last_keypair_balance < enough_lamports {
-        let (_blockhash, fee_calculator) = get_recent_blockhash(client.as_ref());
+        let fee_rate_governor = client.get_fee_rate_governor().unwrap();
-        let max_fee = fee_calculator.max_lamports_per_signature;
+        let max_fee = fee_rate_governor.max_lamports_per_signature;
         let extra_fees = extra * max_fee;
         let total_keypairs = keypairs.len() as u64 + 1; // Add one for funding keypair
         let mut total = lamports_per_account * total_keypairs + extra_fees;
@@ -1134,7 +1134,7 @@ mod tests {
     use solana_runtime::bank::Bank;
     use solana_runtime::bank_client::BankClient;
     use solana_sdk::client::SyncClient;
-    use solana_sdk::fee_calculator::FeeCalculator;
+    use solana_sdk::fee_calculator::FeeRateGovernor;
     use solana_sdk::genesis_config::create_genesis_config;
 
     #[test]
@@ -1181,8 +1181,8 @@ mod tests {
     #[test]
     fn test_bench_tps_fund_keys_with_fees() {
         let (mut genesis_config, id) = create_genesis_config(10_000);
-        let fee_calculator = FeeCalculator::new(11, 0);
+        let fee_rate_governor = FeeRateGovernor::new(11, 0);
-        genesis_config.fee_calculator = fee_calculator;
+        genesis_config.fee_rate_governor = fee_rate_governor;
         let bank = Bank::new(&genesis_config);
         let client = Arc::new(BankClient::new(bank));
         let keypair_count = 20;

bench-tps/src/cli.rs

@@ -1,6 +1,6 @@
 use clap::{crate_description, crate_name, App, Arg, ArgMatches};
 use solana_faucet::faucet::FAUCET_PORT;
-use solana_sdk::fee_calculator::FeeCalculator;
+use solana_sdk::fee_calculator::FeeRateGovernor;
 use solana_sdk::signature::{read_keypair_file, Keypair};
 use std::{net::SocketAddr, process::exit, time::Duration};
 
@@ -43,7 +43,7 @@ impl Default for Config {
             client_ids_and_stake_file: String::new(),
             write_to_client_file: false,
             read_from_client_file: false,
-            target_lamports_per_signature: FeeCalculator::default().target_lamports_per_signature,
+            target_lamports_per_signature: FeeRateGovernor::default().target_lamports_per_signature,
             multi_client: true,
             use_move: false,
             num_lamports_per_account: NUM_LAMPORTS_PER_ACCOUNT_DEFAULT,

bench-tps/src/main.rs

@@ -3,7 +3,7 @@ use solana_bench_tps::bench::{do_bench_tps, generate_and_fund_keypairs, generate
 use solana_bench_tps::cli;
 use solana_core::gossip_service::{discover_cluster, get_client, get_multi_client};
 use solana_genesis::Base64Account;
-use solana_sdk::fee_calculator::FeeCalculator;
+use solana_sdk::fee_calculator::FeeRateGovernor;
 use solana_sdk::signature::{Keypair, Signer};
 use solana_sdk::system_program;
 use std::{collections::HashMap, fs::File, io::prelude::*, path::Path, process::exit, sync::Arc};
@@ -41,7 +41,7 @@ fn main() {
         let (keypairs, _) = generate_keypairs(&id, keypair_count as u64);
         let num_accounts = keypairs.len() as u64;
         let max_fee =
-            FeeCalculator::new(*target_lamports_per_signature, 0).max_lamports_per_signature;
+            FeeRateGovernor::new(*target_lamports_per_signature, 0).max_lamports_per_signature;
         let num_lamports_per_account = (num_accounts - 1 + NUM_SIGNATURES_FOR_TXS * max_fee)
             / num_accounts
             + num_lamports_per_account;

cli/src/offline.rs

@@ -201,7 +201,7 @@ mod tests {
     fn test_blockhashspec_get_blockhash_fee_calc() {
         let test_blockhash = hash(&[0u8]);
         let rpc_blockhash = hash(&[1u8]);
-        let rpc_fee_calc = FeeCalculator::new(42, 42);
+        let rpc_fee_calc = FeeCalculator::new(42);
         let get_recent_blockhash_response = json!(Response {
             context: RpcResponseContext { slot: 1 },
             value: json!((

client/src/mock_rpc_client_request.rs

@@ -6,7 +6,7 @@ use crate::{
 };
 use serde_json::{Number, Value};
 use solana_sdk::{
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     instruction::InstructionError,
     transaction::{self, TransactionError},
 };
@@ -71,6 +71,10 @@ impl GenericRpcClientRequest for MockRpcClientRequest {
                     serde_json::to_value(FeeCalculator::default()).unwrap(),
                 ),
             })?,
+            RpcRequest::GetFeeRateGovernor => serde_json::to_value(Response {
+                context: RpcResponseContext { slot: 1 },
+                value: serde_json::to_value(FeeRateGovernor::default()).unwrap(),
+            })?,
             RpcRequest::GetSignatureStatus => {
                 let response: Option<transaction::Result<()>> = if self.url == "account_in_use" {
                     Some(Err(TransactionError::AccountInUse))

client/src/rpc_client.rs

@@ -6,8 +6,8 @@ use crate::{
     rpc_request::RpcRequest,
     rpc_response::{
         Response, RpcAccount, RpcBlockhashFeeCalculator, RpcConfirmedBlock, RpcContactInfo,
-        RpcEpochInfo, RpcKeyedAccount, RpcLeaderSchedule, RpcResponse, RpcVersionInfo,
+        RpcEpochInfo, RpcFeeRateGovernor, RpcKeyedAccount, RpcLeaderSchedule, RpcResponse,
-        RpcVoteAccountStatus,
+        RpcVersionInfo, RpcVoteAccountStatus,
     },
 };
 use bincode::serialize;
@@ -18,7 +18,7 @@ use solana_sdk::{
     clock::{Slot, UnixTimestamp, DEFAULT_TICKS_PER_SECOND, DEFAULT_TICKS_PER_SLOT},
     commitment_config::CommitmentConfig,
     epoch_schedule::EpochSchedule,
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     hash::Hash,
     inflation::Inflation,
     pubkey::Pubkey,
@@ -804,6 +804,31 @@ impl RpcClient {
         })
     }
 
+    pub fn get_fee_rate_governor(&self) -> RpcResponse<FeeRateGovernor> {
+        let response = self
+            .client
+            .send(&RpcRequest::GetFeeRateGovernor, Value::Null, 0)
+            .map_err(|e| {
+                io::Error::new(
+                    io::ErrorKind::Other,
+                    format!("GetFeeRateGovernor request failure: {:?}", e),
+                )
+            })?;
+        let Response {
+            context,
+            value: RpcFeeRateGovernor { fee_rate_governor },
+        } = serde_json::from_value::<Response<RpcFeeRateGovernor>>(response).map_err(|e| {
+            io::Error::new(
+                io::ErrorKind::Other,
+                format!("GetFeeRateGovernor parse failure: {:?}", e),
+            )
+        })?;
+        Ok(Response {
+            context,
+            value: fee_rate_governor,
+        })
+    }
+
     pub fn get_new_blockhash(&self, blockhash: &Hash) -> io::Result<(Hash, FeeCalculator)> {
         let mut num_retries = 0;
         let start = Instant::now();

client/src/rpc_request.rs

@@ -20,6 +20,7 @@ pub enum RpcRequest {
     GetNumBlocksSinceSignatureConfirmation,
     GetProgramAccounts,
     GetRecentBlockhash,
+    GetFeeRateGovernor,
     GetSignatureStatus,
     GetSlot,
     GetSlotLeader,
@@ -61,6 +62,7 @@ impl RpcRequest {
             }
             RpcRequest::GetProgramAccounts => "getProgramAccounts",
             RpcRequest::GetRecentBlockhash => "getRecentBlockhash",
+            RpcRequest::GetFeeRateGovernor => "getFeeRateGovernor",
             RpcRequest::GetSignatureStatus => "getSignatureStatus",
             RpcRequest::GetSlot => "getSlot",
             RpcRequest::GetSlotLeader => "getSlotLeader",
@@ -138,6 +140,10 @@ mod tests {
         let request = test_request.build_request_json(1, Value::Null);
         assert_eq!(request["method"], "getRecentBlockhash");
 
+        let test_request = RpcRequest::GetFeeRateGovernor;
+        let request = test_request.build_request_json(1, Value::Null);
+        assert_eq!(request["method"], "getFeeRateGovernor");
+
         let test_request = RpcRequest::GetSlot;
         let request = test_request.build_request_json(1, Value::Null);
         assert_eq!(request["method"], "getSlot");

client/src/rpc_response.rs

@@ -4,7 +4,7 @@ use jsonrpc_core::Result as JsonResult;
 use solana_sdk::{
     account::Account,
     clock::{Epoch, Slot},
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     message::MessageHeader,
     pubkey::Pubkey,
     transaction::{Result, Transaction},
@@ -152,6 +152,12 @@ pub struct RpcBlockhashFeeCalculator {
     pub fee_calculator: FeeCalculator,
 }
 
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct RpcFeeRateGovernor {
+    pub fee_rate_governor: FeeRateGovernor,
+}
+
 #[derive(Serialize, Deserialize, Clone, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct RpcKeyedAccount {

client/src/thin_client.rs

@@ -11,7 +11,7 @@ use solana_sdk::{
     client::{AsyncClient, Client, SyncClient},
     clock::MAX_PROCESSING_AGE,
     commitment_config::CommitmentConfig,
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     hash::Hash,
     instruction::Instruction,
     message::Message,
@@ -445,6 +445,11 @@ impl SyncClient for ThinClient {
         }
     }
 
+    fn get_fee_rate_governor(&self) -> TransportResult<FeeRateGovernor> {
+        let fee_rate_governor = self.rpc_client().get_fee_rate_governor()?;
+        Ok(fee_rate_governor.value)
+    }
+
     fn get_signature_status(
         &self,
         signature: &Signature,

core/src/rpc.rs

@@ -9,9 +9,9 @@ use jsonrpc_core::{Error, Metadata, Result};
 use jsonrpc_derive::rpc;
 use solana_client::rpc_response::{
     Response, RpcAccount, RpcBlockCommitment, RpcBlockhashFeeCalculator, RpcConfirmedBlock,
-    RpcContactInfo, RpcEpochInfo, RpcKeyedAccount, RpcLeaderSchedule, RpcResponseContext,
+    RpcContactInfo, RpcEpochInfo, RpcFeeRateGovernor, RpcKeyedAccount, RpcLeaderSchedule,
-    RpcSignatureConfirmation, RpcStorageTurn, RpcTransactionEncoding, RpcVersionInfo,
+    RpcResponseContext, RpcSignatureConfirmation, RpcStorageTurn, RpcTransactionEncoding,
-    RpcVoteAccountInfo, RpcVoteAccountStatus,
+    RpcVersionInfo, RpcVoteAccountInfo, RpcVoteAccountStatus,
 };
 use solana_faucet::faucet::request_airdrop_transaction;
 use solana_ledger::{
@@ -164,6 +164,17 @@ impl JsonRpcRequestProcessor {
         )
     }
 
+    fn get_fee_rate_governor(&self) -> RpcResponse<RpcFeeRateGovernor> {
+        let bank = &*self.bank(None);
+        let fee_rate_governor = bank.get_fee_rate_governor();
+        new_response(
+            bank,
+            RpcFeeRateGovernor {
+                fee_rate_governor: fee_rate_governor.clone(),
+            },
+        )
+    }
+
     pub fn confirm_transaction(
         &self,
         signature: Result<Signature>,
@@ -491,6 +502,9 @@ pub trait RpcSol {
         commitment: Option<CommitmentConfig>,
     ) -> RpcResponse<RpcBlockhashFeeCalculator>;
 
+    #[rpc(meta, name = "getFeeRateGovernor")]
+    fn get_fee_rate_governor(&self, meta: Self::Metadata) -> RpcResponse<RpcFeeRateGovernor>;
+
     #[rpc(meta, name = "getSignatureStatus")]
     fn get_signature_status(
         &self,
@@ -813,6 +827,14 @@ impl RpcSol for RpcSolImpl {
             .get_recent_blockhash(commitment)
     }
 
+    fn get_fee_rate_governor(&self, meta: Self::Metadata) -> RpcResponse<RpcFeeRateGovernor> {
+        debug!("get_fee_rate_governor rpc request received");
+        meta.request_processor
+            .read()
+            .unwrap()
+            .get_fee_rate_governor()
+    }
+
     fn get_signature_status(
         &self,
         meta: Self::Metadata,
@@ -1770,8 +1792,32 @@ pub mod tests {
             "value":{
                 "blockhash": blockhash.to_string(),
                 "feeCalculator": {
-                    "burnPercent": DEFAULT_BURN_PERCENT,
                     "lamportsPerSignature": 0,
+                }
+            }},
+            "id": 1
+        });
+        let expected: Response =
+            serde_json::from_value(expected).expect("expected response deserialization");
+        let result: Response = serde_json::from_str(&res.expect("actual response"))
+            .expect("actual response deserialization");
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    fn test_rpc_get_fee_rate_governor() {
+        let bob_pubkey = Pubkey::new_rand();
+        let RpcHandler { io, meta, .. } = start_rpc_handler_with_tx(&bob_pubkey);
+
+        let req = format!(r#"{{"jsonrpc":"2.0","id":1,"method":"getFeeRateGovernor"}}"#);
+        let res = io.handle_request_sync(&req, meta);
+        let expected = json!({
+            "jsonrpc": "2.0",
+            "result": {
+            "context":{"slot":0},
+            "value":{
+                "feeRateGovernor": {
+                    "burnPercent": DEFAULT_BURN_PERCENT,
                     "maxLamportsPerSignature": 0,
                     "minLamportsPerSignature": 0,
                     "targetLamportsPerSignature": 0,

core/src/validator.rs

@@ -680,7 +680,7 @@ impl TestValidator {
 
     pub fn run_with_options(options: TestValidatorOptions) -> Self {
         use crate::genesis_utils::{create_genesis_config_with_leader_ex, GenesisConfigInfo};
-        use solana_sdk::fee_calculator::FeeCalculator;
+        use solana_sdk::fee_calculator::FeeRateGovernor;
 
         let TestValidatorOptions {
             fees,
@@ -706,7 +706,7 @@ impl TestValidator {
 
         genesis_config.rent.lamports_per_byte_year = 1;
         genesis_config.rent.exemption_threshold = 1.0;
-        genesis_config.fee_calculator = FeeCalculator::new(fees, 0);
+        genesis_config.fee_rate_governor = FeeRateGovernor::new(fees, 0);
 
         let (ledger_path, blockhash) = create_new_tmp_ledger!(&genesis_config);
 

docs/src/apps/jsonrpc-api.md

@@ -24,6 +24,7 @@ To interact with a Solana node inside a JavaScript application, use the [solana-
 * [getConfirmedBlocks](jsonrpc-api.md#getconfirmedblocks)
 * [getEpochInfo](jsonrpc-api.md#getepochinfo)
 * [getEpochSchedule](jsonrpc-api.md#getepochschedule)
+* [getFeeRateGovernor](jsonrpc-api.md#getfeerategovernor)
 * [getGenesisHash](jsonrpc-api.md#getgenesishash)
 * [getInflation](jsonrpc-api.md#getinflation)
 * [getLeaderSchedule](jsonrpc-api.md#getleaderschedule)
@@ -403,6 +404,34 @@ curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "m
 {"jsonrpc":"2.0","result":{"firstNormalEpoch":8,"firstNormalSlot":8160,"leaderScheduleSlotOffset":8192,"slotsPerEpoch":8192,"warmup":true},"id":1}
 ```
 
+### getFeeRateGovernor
+
+Returns the fee rate governor information from the root bank
+
+#### Parameters:
+
+None
+
+#### Results:
+
+The `result` field will be an `object` with the following fields:
+
+* `burnPercent: <u8>`, Percentage of fees collected to be destroyed
+* `maxLamportsPerSignature: <u64>`, Largest value `lamportsPerSignature` can attain for the next slot
+* `minLamportsPerSignature: <u64>`, Smallest value `lamportsPerSignature` can attain for the next slot
+* `targetLamportsPerSignature: <u64>`, Desired fee rate for the cluster
+* `targetSignaturesPerSlot: <u64>`, Desired signature rate for the cluster
+
+#### Example:
+
+```bash
+// Request
+curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1, "method":"getFeeRateGovernor"}' http://localhost:8899
+
+// Result
+{"jsonrpc":"2.0","result":{"context":{"slot":54},"value":{"feeRateGovernor":{"burnPercent":50,"maxLamportsPerSignature":100000,"minLamportsPerSignature":5000,"targetLamportsPerSignature":10000,"targetSignaturesPerSlot":20000}}},"id":1}
+```
+
 ### getGenesisHash
 
 Returns the genesis hash

genesis/src/main.rs

@@ -11,7 +11,7 @@ use solana_sdk::{
     account::Account,
     clock,
     epoch_schedule::EpochSchedule,
-    fee_calculator::FeeCalculator,
+    fee_calculator::FeeRateGovernor,
     genesis_config::{GenesisConfig, OperatingMode},
     native_token::sol_to_lamports,
     poh_config::PohConfig,
@@ -99,16 +99,16 @@ pub fn load_genesis_accounts(file: &str, genesis_config: &mut GenesisConfig) ->
 
 #[allow(clippy::cognitive_complexity)]
 fn main() -> Result<(), Box<dyn error::Error>> {
-    let fee_calculator = FeeCalculator::default();
+    let fee_rate_governor = FeeRateGovernor::default();
     let (
         default_target_lamports_per_signature,
         default_target_signatures_per_slot,
         default_fee_burn_percentage,
     ) = {
         (
-            &fee_calculator.target_lamports_per_signature.to_string(),
+            &fee_rate_governor.target_lamports_per_signature.to_string(),
-            &fee_calculator.target_signatures_per_slot.to_string(),
+            &fee_rate_governor.target_signatures_per_slot.to_string(),
-            &fee_calculator.burn_percent.to_string(),
+            &fee_rate_governor.burn_percent.to_string(),
         )
     };
 
@@ -449,11 +449,11 @@ fn main() -> Result<(), Box<dyn error::Error>> {
 
     let ticks_per_slot = value_t_or_exit!(matches, "ticks_per_slot", u64);
 
-    let mut fee_calculator = FeeCalculator::new(
+    let mut fee_rate_governor = FeeRateGovernor::new(
         value_t_or_exit!(matches, "target_lamports_per_signature", u64),
-        value_t_or_exit!(matches, "target_signatures_per_slot", usize),
+        value_t_or_exit!(matches, "target_signatures_per_slot", u64),
     );
-    fee_calculator.burn_percent = value_t_or_exit!(matches, "fee_burn_percentage", u8);
+    fee_rate_governor.burn_percent = value_t_or_exit!(matches, "fee_burn_percentage", u8);
 
     let mut poh_config = PohConfig::default();
     poh_config.target_tick_duration = if matches.is_present("target_tick_duration") {
@@ -513,7 +513,7 @@ fn main() -> Result<(), Box<dyn error::Error>> {
         ticks_per_slot,
         epoch_schedule,
         inflation,
-        fee_calculator,
+        fee_rate_governor,
         rent,
         poh_config,
         operating_mode,

genesis/src/stakes.rs

@@ -25,7 +25,7 @@ pub struct StakerInfo {
 //  lamports to cover TX fees (delegation) for one year,
 //  and we support one delegation per epoch
 fn calculate_staker_fees(genesis_config: &GenesisConfig, years: f64) -> u64 {
-    genesis_config.fee_calculator.max_lamports_per_signature
+    genesis_config.fee_rate_governor.max_lamports_per_signature
         * genesis_config.epoch_schedule.get_epoch(years_as_slots(
             years,
             &genesis_config.poh_config.target_tick_duration,

programs/bpf/rust/sysval/src/lib.rs

@@ -36,8 +36,8 @@ fn process_instruction(
     info!("Fees identifier:");
     sysvar::fees::id().log();
     let fees = Fees::from_account_info(&accounts[3]).expect("fees");
-    let burn = fees.fee_calculator.burn(42);
+    let fee_calculator = fees.fee_calculator;
-    assert_eq!(burn, (21, 21));
+    assert_eq!(fee_calculator.lamports_per_signature, 0);
 
     // Rewards
     info!("Rewards identifier:");

runtime/src/accounts.rs

@@ -853,7 +853,7 @@ mod tests {
             instructions,
         );
 
-        let fee_calculator = FeeCalculator::new(10, 0);
+        let fee_calculator = FeeCalculator::new(10);
         assert_eq!(fee_calculator.calculate_fee(tx.message()), 10);
 
         let loaded_accounts =
@@ -918,7 +918,7 @@ mod tests {
         let min_balance = rent_collector
             .rent
             .minimum_balance(nonce_state::NonceState::size());
-        let fee_calculator = FeeCalculator::new(min_balance, 0);
+        let fee_calculator = FeeCalculator::new(min_balance);
         let nonce = Keypair::new();
         let mut accounts = vec![(
             nonce.pubkey(),

runtime/src/bank.rs

@@ -35,7 +35,7 @@ use solana_sdk::{
     account::Account,
     clock::{get_segment_from_slot, Epoch, Slot, UnixTimestamp, MAX_RECENT_BLOCKHASHES},
     epoch_schedule::EpochSchedule,
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     genesis_config::GenesisConfig,
     hard_forks::HardForks,
     hash::{extend_and_hash, hashv, Hash},
@@ -302,6 +302,9 @@ pub struct Bank {
     /// Latest transaction fees for transactions processed by this bank
     fee_calculator: FeeCalculator,
 
+    /// Track cluster signature throughput and adjust fee rate
+    fee_rate_governor: FeeRateGovernor,
+
     /// Rent that have been collected
     #[serde(serialize_with = "serialize_atomicu64")]
     #[serde(deserialize_with = "deserialize_atomicu64")]
@@ -401,6 +404,9 @@ impl Bank {
         let epoch_schedule = parent.epoch_schedule;
         let epoch = epoch_schedule.get_epoch(slot);
 
+        let fee_rate_governor =
+            FeeRateGovernor::new_derived(&parent.fee_rate_governor, parent.signature_count());
+
         let mut new = Bank {
             rc,
             src,
@@ -420,10 +426,8 @@ impl Bank {
             rent_collector: parent.rent_collector.clone_with_epoch(epoch),
             max_tick_height: (slot + 1) * parent.ticks_per_slot,
             block_height: parent.block_height + 1,
-            fee_calculator: FeeCalculator::new_derived(
+            fee_calculator: fee_rate_governor.create_fee_calculator(),
-                &parent.fee_calculator,
+            fee_rate_governor,
-                parent.signature_count() as usize,
-            ),
             capitalization: AtomicU64::new(parent.capitalization()),
             inflation: parent.inflation.clone(),
             transaction_count: AtomicU64::new(parent.transaction_count()),
@@ -745,7 +749,7 @@ impl Bank {
         let collector_fees = self.collector_fees.load(Ordering::Relaxed) as u64;
 
         if collector_fees != 0 {
-            let (unburned, burned) = self.fee_calculator.burn(collector_fees);
+            let (unburned, burned) = self.fee_rate_governor.burn(collector_fees);
             // burn a portion of fees
             self.deposit(&self.collector_id, unburned);
             self.capitalization.fetch_sub(burned, Ordering::Relaxed);
@@ -811,7 +815,8 @@ impl Bank {
 
     fn process_genesis_config(&mut self, genesis_config: &GenesisConfig) {
         // Bootstrap validator collects fees until `new_from_parent` is called.
-        self.fee_calculator = genesis_config.fee_calculator.clone();
+        self.fee_rate_governor = genesis_config.fee_rate_governor.clone();
+        self.fee_calculator = self.fee_rate_governor.create_fee_calculator();
         self.update_fees();
 
         for (pubkey, account) in genesis_config.accounts.iter() {
@@ -905,6 +910,10 @@ impl Bank {
         blockhash_queue.get_fee_calculator(hash).cloned()
     }
 
+    pub fn get_fee_rate_governor(&self) -> &FeeRateGovernor {
+        &self.fee_rate_governor
+    }
+
     pub fn confirmed_last_blockhash(&self) -> (Hash, FeeCalculator) {
         const NUM_BLOCKHASH_CONFIRMATIONS: usize = 3;
 
@@ -3290,7 +3299,7 @@ mod tests {
     #[test]
     fn test_detect_failed_duplicate_transactions() {
         let (mut genesis_config, mint_keypair) = create_genesis_config(2);
-        genesis_config.fee_calculator.lamports_per_signature = 1;
+        genesis_config.fee_rate_governor = FeeRateGovernor::new(1, 0);
         let bank = Bank::new(&genesis_config);
 
         let dest = Keypair::new();
@@ -3450,11 +3459,14 @@ mod tests {
             mint_keypair,
             ..
         } = create_genesis_config_with_leader(mint, &leader, 3);
-        genesis_config.fee_calculator.lamports_per_signature = 4; // something divisible by 2
+        genesis_config.fee_rate_governor = FeeRateGovernor::new(4, 0); // something divisible by 2
 
-        let expected_fee_paid = genesis_config.fee_calculator.lamports_per_signature;
+        let expected_fee_paid = genesis_config
+            .fee_rate_governor
+            .create_fee_calculator()
+            .lamports_per_signature;
         let (expected_fee_collected, expected_fee_burned) =
-            genesis_config.fee_calculator.burn(expected_fee_paid);
+            genesis_config.fee_rate_governor.burn(expected_fee_paid);
 
         let mut bank = Bank::new(&genesis_config);
 
@@ -3521,8 +3533,10 @@ mod tests {
             mint_keypair,
             ..
         } = create_genesis_config_with_leader(1_000_000, &leader, 3);
-        genesis_config.fee_calculator.target_lamports_per_signature = 1000;
+        genesis_config
-        genesis_config.fee_calculator.target_signatures_per_slot = 1;
+            .fee_rate_governor
+            .target_lamports_per_signature = 1000;
+        genesis_config.fee_rate_governor.target_signatures_per_slot = 1;
 
         let mut bank = Bank::new(&genesis_config);
         goto_end_of_slot(&mut bank);
@@ -3571,7 +3585,7 @@ mod tests {
             mint_keypair,
             ..
         } = create_genesis_config_with_leader(100, &leader, 3);
-        genesis_config.fee_calculator.lamports_per_signature = 2;
+        genesis_config.fee_rate_governor = FeeRateGovernor::new(2, 0);
         let bank = Bank::new(&genesis_config);
 
         let key = Keypair::new();
@@ -3598,7 +3612,7 @@ mod tests {
             bank.get_balance(&leader),
             initial_balance
                 + bank
-                    .fee_calculator
+                    .fee_rate_governor
                     .burn(bank.fee_calculator.lamports_per_signature * 2)
                     .0
         );
@@ -4548,15 +4562,20 @@ mod tests {
     }
 
     #[test]
-    fn test_bank_inherit_fee_calculator() {
+    fn test_bank_inherit_fee_rate_governor() {
         let (mut genesis_config, _mint_keypair) = create_genesis_config(500);
-        genesis_config.fee_calculator.target_lamports_per_signature = 123;
+        genesis_config
+            .fee_rate_governor
+            .target_lamports_per_signature = 123;
 
         let bank0 = Arc::new(Bank::new(&genesis_config));
         let bank1 = Arc::new(new_from_parent(&bank0));
         assert_eq!(
-            bank0.fee_calculator.target_lamports_per_signature / 2,
+            bank0.fee_rate_governor.target_lamports_per_signature / 2,
-            bank1.fee_calculator.lamports_per_signature
+            bank1
+                .fee_rate_governor
+                .create_fee_calculator()
+                .lamports_per_signature
         );
     }
 
@@ -4659,7 +4678,7 @@ mod tests {
     #[test]
     fn test_bank_fees_account() {
         let (mut genesis_config, _) = create_genesis_config(500);
-        genesis_config.fee_calculator.lamports_per_signature = 12345;
+        genesis_config.fee_rate_governor = FeeRateGovernor::new(12345, 0);
         let bank = Arc::new(Bank::new(&genesis_config));
 
         let fees_account = bank.get_account(&sysvar::fees::id()).unwrap();
@@ -5443,8 +5462,8 @@ mod tests {
     #[test]
     fn test_pre_post_transaction_balances() {
         let (mut genesis_config, _mint_keypair) = create_genesis_config(500);
-        let fee_calculator = FeeCalculator::new(1, 0);
+        let fee_rate_governor = FeeRateGovernor::new(1, 0);
-        genesis_config.fee_calculator = fee_calculator;
+        genesis_config.fee_rate_governor = fee_rate_governor;
         let parent = Arc::new(Bank::new(&genesis_config));
         let bank0 = Arc::new(new_from_parent(&parent));
 

runtime/src/bank_client.rs

@@ -3,7 +3,7 @@ use solana_sdk::{
     account::Account,
     client::{AsyncClient, Client, SyncClient},
     commitment_config::CommitmentConfig,
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     hash::Hash,
     instruction::Instruction,
     message::Message,
@@ -137,6 +137,10 @@ impl SyncClient for BankClient {
         Ok(self.bank.last_blockhash_with_fee_calculator())
     }
 
+    fn get_fee_rate_governor(&self) -> Result<FeeRateGovernor> {
+        Ok(self.bank.get_fee_rate_governor().clone())
+    }
+
     fn get_signature_status(
         &self,
         signature: &Signature,

runtime/src/genesis_utils.rs

@@ -1,6 +1,6 @@
 use solana_sdk::{
     account::Account,
-    fee_calculator::FeeCalculator,
+    fee_calculator::FeeRateGovernor,
     genesis_config::GenesisConfig,
     pubkey::Pubkey,
     rent::Rent,
@@ -140,11 +140,11 @@ pub fn create_genesis_config_with_leader_ex(
         solana_stake_program!(),
     ];
 
-    let fee_calculator = FeeCalculator::new(0, 0); // most tests can't handle transaction fees
+    let fee_rate_governor = FeeRateGovernor::new(0, 0); // most tests can't handle transaction fees
     let mut genesis_config = GenesisConfig {
         accounts,
         native_instruction_processors,
-        fee_calculator,
+        fee_rate_governor,
         rent,
         ..GenesisConfig::default()
     };

sdk/src/client.rs

@@ -11,7 +11,7 @@ use crate::{
     account::Account,
     clock::Slot,
     commitment_config::CommitmentConfig,
-    fee_calculator::FeeCalculator,
+    fee_calculator::{FeeCalculator, FeeRateGovernor},
     hash::Hash,
     instruction::Instruction,
     message::Message,
@@ -72,6 +72,9 @@ pub trait SyncClient {
         commitment_config: CommitmentConfig,
     ) -> Result<(Hash, FeeCalculator)>;
 
+    /// Get recent fee rate governor
+    fn get_fee_rate_governor(&self) -> Result<FeeRateGovernor>;
+
     /// Get signature status.
     fn get_signature_status(
         &self,

sdk/src/fee_calculator.rs

@@ -8,6 +8,35 @@ pub struct FeeCalculator {
     // The current cost of a signature  This amount may increase/decrease over time based on
     // cluster processing load.
     pub lamports_per_signature: u64,
+}
+
+impl Default for FeeCalculator {
+    fn default() -> Self {
+        Self {
+            lamports_per_signature: 0,
+        }
+    }
+}
+
+impl FeeCalculator {
+    pub fn new(lamports_per_signature: u64) -> Self {
+        Self {
+            lamports_per_signature,
+        }
+    }
+
+    pub fn calculate_fee(&self, message: &Message) -> u64 {
+        self.lamports_per_signature * u64::from(message.header.num_required_signatures)
+    }
+}
+
+#[derive(Serialize, Deserialize, PartialEq, Eq, Clone, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct FeeRateGovernor {
+    // The current cost of a signature  This amount may increase/decrease over time based on
+    // cluster processing load.
+    #[serde(skip)]
+    lamports_per_signature: u64,
 
     // The target cost of a signature when the cluster is operating around target_signatures_per_slot
     // signatures
@@ -16,7 +45,7 @@ pub struct FeeCalculator {
     // Used to estimate the desired processing capacity of the cluster.  As the signatures for
     // recent slots are fewer/greater than this value, lamports_per_signature will decrease/increase
     // for the next slot.  A value of 0 disables lamports_per_signature fee adjustments
-    pub target_signatures_per_slot: usize,
+    pub target_signatures_per_slot: u64,
 
     pub min_lamports_per_signature: u64,
     pub max_lamports_per_signature: u64,
@@ -26,15 +55,15 @@ pub struct FeeCalculator {
 }
 
 pub const DEFAULT_TARGET_LAMPORTS_PER_SIGNATURE: u64 = 10_000;
-pub const DEFAULT_TARGET_SIGNATURES_PER_SLOT: usize =
+pub const DEFAULT_TARGET_SIGNATURES_PER_SLOT: u64 =
-    50_000 * DEFAULT_TICKS_PER_SLOT as usize / DEFAULT_TICKS_PER_SECOND as usize;
+    50_000 * DEFAULT_TICKS_PER_SLOT / DEFAULT_TICKS_PER_SECOND;
 
 // Percentage of tx fees to burn
 pub const DEFAULT_BURN_PERCENT: u8 = 50;
 
-impl Default for FeeCalculator {
+impl Default for FeeRateGovernor {
     fn default() -> Self {
-        FeeCalculator {
+        Self {
             lamports_per_signature: 0,
             target_lamports_per_signature: DEFAULT_TARGET_LAMPORTS_PER_SIGNATURE,
             target_signatures_per_slot: DEFAULT_TARGET_SIGNATURES_PER_SLOT,
@@ -45,23 +74,23 @@ impl Default for FeeCalculator {
     }
 }
 
-impl FeeCalculator {
+impl FeeRateGovernor {
-    pub fn new(target_lamports_per_signature: u64, target_signatures_per_slot: usize) -> Self {
+    pub fn new(target_lamports_per_signature: u64, target_signatures_per_slot: u64) -> Self {
-        let base_fee_calculator = Self {
+        let base_fee_rate_governor = Self {
             target_lamports_per_signature,
             lamports_per_signature: target_lamports_per_signature,
             target_signatures_per_slot,
-            ..FeeCalculator::default()
+            ..FeeRateGovernor::default()
         };
 
-        Self::new_derived(&base_fee_calculator, 0)
+        Self::new_derived(&base_fee_rate_governor, 0)
     }
 
     pub fn new_derived(
-        base_fee_calculator: &FeeCalculator,
+        base_fee_rate_governor: &FeeRateGovernor,
-        latest_signatures_per_slot: usize,
+        latest_signatures_per_slot: u64,
     ) -> Self {
-        let mut me = base_fee_calculator.clone();
+        let mut me = base_fee_rate_governor.clone();
 
         if me.target_signatures_per_slot > 0 {
             // lamports_per_signature can range from 50% to 1000% of
@@ -74,7 +103,7 @@ impl FeeCalculator {
                 me.max_lamports_per_signature
                     .min(me.min_lamports_per_signature.max(
                         me.target_lamports_per_signature
-                            * std::cmp::min(latest_signatures_per_slot, std::u32::MAX as usize)
+                            * std::cmp::min(latest_signatures_per_slot, std::u32::MAX as u64)
                                 as u64
                             / me.target_signatures_per_slot as u64,
                     ));
@@ -85,7 +114,7 @@ impl FeeCalculator {
             );
 
             let gap = desired_lamports_per_signature as i64
-                - base_fee_calculator.lamports_per_signature as i64;
+                - base_fee_rate_governor.lamports_per_signature as i64;
 
             if gap == 0 {
                 me.lamports_per_signature = desired_lamports_per_signature;
@@ -104,11 +133,12 @@ impl FeeCalculator {
                 me.lamports_per_signature =
                     me.max_lamports_per_signature
                         .min(me.min_lamports_per_signature.max(
-                            (base_fee_calculator.lamports_per_signature as i64 + gap_adjust) as u64,
+                            (base_fee_rate_governor.lamports_per_signature as i64 + gap_adjust)
+                                as u64,
                         ));
             }
         } else {
-            me.lamports_per_signature = base_fee_calculator.target_lamports_per_signature;
+            me.lamports_per_signature = base_fee_rate_governor.target_lamports_per_signature;
             me.min_lamports_per_signature = me.target_lamports_per_signature;
             me.max_lamports_per_signature = me.target_lamports_per_signature;
         }
@@ -119,15 +149,18 @@ impl FeeCalculator {
         me
     }
 
-    pub fn calculate_fee(&self, message: &Message) -> u64 {
-        self.lamports_per_signature * u64::from(message.header.num_required_signatures)
-    }
-
     /// calculate unburned fee from a fee total, returns (unburned, burned)
     pub fn burn(&self, fees: u64) -> (u64, u64) {
         let burned = fees * u64::from(self.burn_percent) / 100;
         (fees - burned, burned)
     }
+
+    /// create a FeeCalculator based on current cluster signature throughput
+    pub fn create_fee_calculator(&self) -> FeeCalculator {
+        FeeCalculator {
+            lamports_per_signature: self.lamports_per_signature,
+        }
+    }
 }
 
 #[cfg(test)]
@@ -136,15 +169,15 @@ mod tests {
     use crate::{pubkey::Pubkey, system_instruction};
 
     #[test]
-    fn test_fee_calculator_burn() {
+    fn test_fee_rate_governor_burn() {
-        let mut fee_calculator = FeeCalculator::default();
+        let mut fee_rate_governor = FeeRateGovernor::default();
-        assert_eq!(fee_calculator.burn(2), (1, 1));
+        assert_eq!(fee_rate_governor.burn(2), (1, 1));
 
-        fee_calculator.burn_percent = 0;
+        fee_rate_governor.burn_percent = 0;
-        assert_eq!(fee_calculator.burn(2), (2, 0));
+        assert_eq!(fee_rate_governor.burn(2), (2, 0));
 
-        fee_calculator.burn_percent = 100;
+        fee_rate_governor.burn_percent = 100;
-        assert_eq!(fee_calculator.burn(2), (0, 2));
+        assert_eq!(fee_rate_governor.burn(2), (0, 2));
     }
 
     #[test]
@@ -154,27 +187,27 @@ mod tests {
         assert_eq!(FeeCalculator::default().calculate_fee(&message), 0);
 
         // No signature, no fee.
-        assert_eq!(FeeCalculator::new(1, 0).calculate_fee(&message), 0);
+        assert_eq!(FeeCalculator::new(1).calculate_fee(&message), 0);
 
         // One signature, a fee.
         let pubkey0 = Pubkey::new(&[0; 32]);
         let pubkey1 = Pubkey::new(&[1; 32]);
         let ix0 = system_instruction::transfer(&pubkey0, &pubkey1, 1);
         let message = Message::new(vec![ix0]);
-        assert_eq!(FeeCalculator::new(2, 0).calculate_fee(&message), 2);
+        assert_eq!(FeeCalculator::new(2).calculate_fee(&message), 2);
 
         // Two signatures, double the fee.
         let ix0 = system_instruction::transfer(&pubkey0, &pubkey1, 1);
         let ix1 = system_instruction::transfer(&pubkey1, &pubkey0, 1);
         let message = Message::new(vec![ix0, ix1]);
-        assert_eq!(FeeCalculator::new(2, 0).calculate_fee(&message), 4);
+        assert_eq!(FeeCalculator::new(2).calculate_fee(&message), 4);
     }
 
     #[test]
-    fn test_fee_calculator_derived_default() {
+    fn test_fee_rate_governor_derived_default() {
         solana_logger::setup();
 
-        let f0 = FeeCalculator::default();
+        let f0 = FeeRateGovernor::default();
         assert_eq!(
             f0.target_signatures_per_slot,
             DEFAULT_TARGET_SIGNATURES_PER_SLOT
@@ -185,7 +218,7 @@ mod tests {
         );
         assert_eq!(f0.lamports_per_signature, 0);
 
-        let f1 = FeeCalculator::new_derived(&f0, DEFAULT_TARGET_SIGNATURES_PER_SLOT);
+        let f1 = FeeRateGovernor::new_derived(&f0, DEFAULT_TARGET_SIGNATURES_PER_SLOT);
         assert_eq!(
             f1.target_signatures_per_slot,
             DEFAULT_TARGET_SIGNATURES_PER_SLOT
@@ -201,20 +234,20 @@ mod tests {
     }
 
     #[test]
-    fn test_fee_calculator_derived_adjust() {
+    fn test_fee_rate_governor_derived_adjust() {
         solana_logger::setup();
 
-        let mut f = FeeCalculator::default();
+        let mut f = FeeRateGovernor::default();
         f.target_lamports_per_signature = 100;
         f.target_signatures_per_slot = 100;
-        f = FeeCalculator::new_derived(&f, 0);
+        f = FeeRateGovernor::new_derived(&f, 0);
 
         // Ramp fees up
         let mut count = 0;
         loop {
             let last_lamports_per_signature = f.lamports_per_signature;
 
-            f = FeeCalculator::new_derived(&f, std::usize::MAX);
+            f = FeeRateGovernor::new_derived(&f, std::u64::MAX);
             info!("[up] f.lamports_per_signature={}", f.lamports_per_signature);
 
             // some maximum target reached
@@ -230,7 +263,7 @@ mod tests {
         let mut count = 0;
         loop {
             let last_lamports_per_signature = f.lamports_per_signature;
-            f = FeeCalculator::new_derived(&f, 0);
+            f = FeeRateGovernor::new_derived(&f, 0);
 
             info!(
                 "[down] f.lamports_per_signature={}",
@@ -250,7 +283,7 @@ mod tests {
         // Arrive at target rate
         let mut count = 0;
         while f.lamports_per_signature != f.target_lamports_per_signature {
-            f = FeeCalculator::new_derived(&f, f.target_signatures_per_slot);
+            f = FeeRateGovernor::new_derived(&f, f.target_signatures_per_slot);
             info!(
                 "[target] f.lamports_per_signature={}",
                 f.lamports_per_signature

sdk/src/genesis_config.rs

@@ -4,7 +4,7 @@ use crate::{
     account::Account,
     clock::{UnixTimestamp, DEFAULT_SLOTS_PER_SEGMENT, DEFAULT_TICKS_PER_SLOT},
     epoch_schedule::EpochSchedule,
-    fee_calculator::FeeCalculator,
+    fee_calculator::FeeRateGovernor,
     hash::{hash, Hash},
     inflation::Inflation,
     native_token::lamports_to_sol,
@@ -49,7 +49,7 @@ pub struct GenesisConfig {
     /// network speed configuration
     pub poh_config: PohConfig,
     /// transaction fee config
-    pub fee_calculator: FeeCalculator,
+    pub fee_rate_governor: FeeRateGovernor,
     /// rent config
     pub rent: Rent,
     /// inflation config
@@ -89,7 +89,7 @@ impl Default for GenesisConfig {
             slots_per_segment: DEFAULT_SLOTS_PER_SEGMENT,
             poh_config: PohConfig::default(),
             inflation: Inflation::default(),
-            fee_calculator: FeeCalculator::default(),
+            fee_rate_governor: FeeRateGovernor::default(),
             rent: Rent::default(),
             epoch_schedule: EpochSchedule::default(),
             operating_mode: OperatingMode::Development,
@@ -205,7 +205,7 @@ impl fmt::Display for GenesisConfig {
                 "dis"
             },
             self.rent,
-            self.fee_calculator,
+            self.fee_rate_governor,
             lamports_to_sol(
                 self.accounts
                     .iter()