Summary of Changes
Create a plugin mechanism in the accounts update path so that accounts data can be streamed out to external data stores (be it Kafka or Postgres). The plugin mechanism allows
Data stores of connection strings/credentials to be configured,
Accounts with patterns to be streamed
PostgreSQL implementation of the streaming for different destination stores to be plugged in.
The code comprises 4 major parts:
accountsdb-plugin-intf: defines the plugin interface which concrete plugin should implement.
accountsdb-plugin-manager: manages the load/unload of plugins and provide interfaces which the validator can notify of accounts update to plugins.
accountsdb-plugin-postgres: the concrete plugin implementation for PostgreSQL
The validator integrations: updated streamed right after snapshot restore and after account update from transaction processing or other real updates.
The plugin is optionally loaded on demand by new validator CLI argument -- there is no impact if the plugin is not loaded.
AccountsBackgroundService now knows about incremental snapshots. It is
now also in charge of deciding if an AccountsPackage is destined to be a
SnapshotPackage or not (or just used by AccountsHashVerifier).
!!! New behavior changes !!!
Taking snapshots (both bank and archive) **MUST** succeed.
This is required because of how the last full snapshot slot is
calculated, which is used by AccountsBackgroundService when calling
`clean_accounts()`.
File system calls are now unwrapped and will result in a crash. As Trent told me:
>Well I think if a snapshot fails due to some IO error, it's very likely that the operator is going to have to intervene before it works. We should exit error in this case, otherwise the validator might happily spin for several more hours, never successfully writing a complete snapshot, before something else brings it down. This would leave the validator's last local snapshot many more slots behind than it would be had we exited outright and potentially force the operator to abandon ledger continuity in favor of a quick catchup
Other errors will set the `exit` flag to `true`, and the node will gracefully shutdown.
Fixes#19167Fixes#19168
#### Problem
Snapshot names are overloaded, and there are multiple terms that mean the same thing. This is confusing. Here's a list of ones in the codebase that I've found:
```
- snapshot_dir
- snapshots_dir
- snapshot_path
- snapshot_output_dir
- snapshot_package_output_path
- snapshot_archives_dir
```
#### Summary of Changes
For all the ones that are about the directory where snapshot archives are stored, ensure they are `snapshot_archives_dir`. For the ones about the (bank) snapshots directory, set to `bank_snapshots_dir`.
Co-authored-by: Michael Vines <mvines@gmail.com>
Renaming these types to better communicate their usages, which will
further diverge as incremental snapshot support is added.
With the new names, AccountsPacakge now refers to the type between
AccountsBackgroundProcess and AccountsHashVerifier, and SnapshotPackage
refers to the type between AccountsHashVerifier and
SnapshotPackagerService.
Add a test for snapshots that spins up AccountsBackgroundService,
AccountsHashVerifier, and SnapshotPackagerService.
Currently there is not a test for snapshots that spins up the background
services fully. This means that there's not a current test that I can
use when adding incremental snapshot support to these three services.
Fixes#19014
Filtering out storages for incremental snapshots will be needed by the
background services for incremental snapshot support, but there is not a
Bank at that point. Since the filtering doesn't apply only to Bank, and
more to snapshots, move the functionality into snapshot_utils.
While reviewing PR #18565, as issue was brought up to refactor some code
around verifying the bank after rebuilding from snapshots. A new
top-level function has been added to get the latest snapshot archives
and load the bank then verify. Additionally, new tests have been
written and existing tests have been updated to use this new function.
Fixes#18973
While resolving the issue, it became clear there was some additional
low-hanging fruit this change enabled. Specifically, the functions
`bank_to_xxx_snapshot_archive()` now return their respective
`SnapshotArchiveInfo`. And on the flip side,
`bank_from_snapshot_archives()` now takes `SnapshotArchiveInfo`s instead
of separate paths and archive formats. This bundling simplifies bank
rebuilding.
This commit also renames `snapshot_interval_slots` to
`full_snapshot_archive_interval_slots`, updates the comments on the
fields, and make appropriate updates where SnapshotConfig is used.
This PR solves #18815. Note that I had to make the snapshot prefix
constants inside `snapshot_utils.rs` public at the crate level in order
to make this work. I'm not sure whether or not introducing this
dependency is entirely good, either way the `snapshot_utils.rs` file
needs a lot of rework so things will move around, I believe this does
the work in the meantime. Any feedback will be greatly appreciated.
This commit builds on PR #18504 by adding a test to core/tests/snapshot.rs for Incremental Snapshots. The test adds banks to bank forks in a loop and takes both full snapshots and incremental snapshots at intervals, and validates they are rebuild-able.
For background info about Incremental Snapshots, see #17088.
Fixes#18829 and #18972
This commit adds high-level functions for creating and loading-from
incremental snapshots, plus all low-level functions required to perform
those tasks. This commit **does not** add taking incremental snapshots
as part of a running validator, nor starting up a node with an
incremental snapshot; just laying ground work.
Additionally, `snapshot_utils` and `serde_snapshot` have been
refactored to use a common code paths for the different snapshots.
Also of note, some renaming has happened:
1. Snapshots are now either `full_` or `incremental_` throughout the
codebase. If not specified, the code applies to both.
2. Bank snapshots now are called "bank snapshots"
(before they were called "slot snapshots", "bank snapshots", or
just "snapshots"). The one exception is within `Bank`, where they
are still just "snapshots", because they are already "bank
snapshots".
3. Snapshot archives now have `_archive` in the code. This
should clear up an ambiguity between bank snapshots and snapshot
archives.
1. Added both options for measuring space usage using total accounts usage and for individual store shrink ratio using an enum. Validator CLI options: --accounts-shrink-optimize-total-space and --accounts-shrink-ratio
2. Added code for selecting candidates based on total usage in a separate function select_candidates_by_total_usage
3. Added unit tests for the new functions added
4. The default implementations is kept at 0.8 shrink ratio with --accounts-shrink-optimize-total-space set to true
Fixes#17544
