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.
AccountsHashVerifier will need access to both the full and incremental
snapshot archive interval slots config values, which is in the
SnapshotConfig.
Also, cleanup some `Option<>` params and their references.
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.
bank.get_leader_schedule_epoch(shred_slot)
is one epoch after epoch_schedule.get_epoch(shred_slot).
At epoch boundaries, shred is already one epoch after the root-slot. So
we need epoch-stakes 2 epochs ahead of the root. But the root bank only
has epoch-stakes for one epoch ahead, and as a result looking up epoch
staked-nodes from the root-bank fails.
To be backward compatible with the current master code, this commit
implements a fallback on working-bank if epoch staked-nodes obtained
from the root-bank is none.
If two threads simultaneously call into ClusterNodesCache::get for the
same epoch, and the cache entry is outdated, then both threads recompute
cluster-nodes for the epoch and redundantly overwrite each other.
This commit wraps ClusterNodesCache entries in Arc<Mutex<...>>, so that
when needed only one thread does the computations to update the entry.
* Current caching mechanism does not update cluster-nodes when the epoch
(and so epoch staked nodes) changes:
https://github.com/solana-labs/solana/blob/19bd30262/core/src/broadcast_stage/standard_broadcast_run.rs#L332-L344
* Additionally, the cache update has a concurrency bug in which the
thread which does compare_and_swap may be blocked when it tries to
obtain the write-lock on cache, while other threads will keep running
ahead with the outdated cache (since the atomic timestamp is already
updated).
In the new ClusterNodesCache, entries are keyed by epoch, and so if
epoch changes cluster-nodes will be recalculated. The time-to-live
eviction policy is also encapsulated and rigidly enforced.
The new cluster-nodes cache will:
* ensure cluster-nodes are recalculated if the epoch (and so the epoch
staked nodes) changes.
* encapsulate time-to-live eviction policy.
Cluster nodes are cached keyed by the respective epoch from which stakes
are obtained, and so if epoch changes cluster-nodes will be recomputed.
A time-to-live eviction policy is enforced to refresh entries in case
gossip contact-infos are updated.
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.
* wip - cost_update_services to log both us and cu for each instruction to determine possible ratio
* replace microsecond with compute_unit as cost unit
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
