fix(rust_brain): preserve HLC on snapshot restore and gossip receive#38
Draft
cursor[bot] wants to merge 1 commit into
Draft
fix(rust_brain): preserve HLC on snapshot restore and gossip receive#38cursor[bot] wants to merge 1 commit into
cursor[bot] wants to merge 1 commit into
Conversation
After v0.6.0 added HLC monotonic enforcement, restore_from_file() and gossip.receive() still assigned fresh HLC timestamps. Post-restore causal writes were rejected (TimestampRegression) causing silent data loss; gossip without HLC could overwrite fresher data. - Add _parse_hlc() for snapshot/wire normalization with legacy fallback - Restore HLC and advance global clock on snapshot restore - Pass HLC through bulk_write and gossip receive with stale rejection - Hold lock during restore_from_file and gc_expired to prevent races Co-authored-by: Daniel <DJLougen@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Bug and impact
After v0.6.0 added HLC-based monotonic enforcement,
restore_from_file()andgossip.receive()still assigned fresh HLC timestamps instead of preserving/applying the stored ones.Concrete trigger: Snapshot a node with
hlc=(5000, 10, "nodeA"), restore, then apply a causal successor writehlc=(5000, 11, "nodeA"). The restore assigns a fresh wall-clock HLC, so the successor is rejected withTimestampRegression— silent data loss on disaster recovery and replication.Gossip without HLC could also overwrite fresher local data on existing keys.
Root cause
restore_from_file()rebuiltMemoryNodewithout reading thehlcfield from snapshots.gossip.receive()calledremember()without passinghlc,ts_ns, oredges.Fix
_parse_hlc()for snapshot/wire normalization with legacyts_nsfallback_hlc.update()on snapshot restorebulk_writeand gossip receive with stale-update rejectionrestore_from_file()andgc_expired()to prevent racesValidation
pytest tests/test_enterprise_backup.py tests/test_gossip.py tests/test_rust_brain.py tests/test_rust_brain_concurrency.py— 37 passed