fix(rust_brain): preserve HLC timestamps on restore, bulk_write, and gossip - #80
Draft
cursor[bot] wants to merge 1 commit into
Draft
fix(rust_brain): preserve HLC timestamps on restore, bulk_write, and gossip#80cursor[bot] wants to merge 1 commit into
cursor[bot] wants to merge 1 commit into
Conversation
…gossip restore_from_file() assigned fresh HLC timestamps instead of reading the hlc field from snapshots. After crash recovery, gossip replays and causal successor writes with pre-crash HLC were rejected with TimestampRegression, causing silent data loss in distributed deployments. - Add _parse_hlc() helper for snapshot/wire HLC normalization - restore_from_file: restore hlc, update global HLC, hold lock during restore - bulk_write: pass through hlc from row payloads - gossip.receive: apply peer HLC, skip stale/missing-hlc updates on existing keys - Add regression tests in test_hlc_snapshot_gossip.py 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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
restore_from_file(),bulk_write(), andgossip.receive()did not preserve or apply Hybrid Logical Clock (HLC) timestamps introduced in v0.6.0. After snapshot restore, gossip replays and causal successor writes with pre-crash HLC values were rejected withTimestampRegression, causing silent data loss in distributed deployments.Concrete trigger: Node writes
k1withhlc=(5000, 10, "nodeA"), snapshots, crashes, restores. Restore assigns a fresh HLC(wall, 0, uuid)instead of the snapshot value. A peer gossipinghlc=(5000, 11, "nodeA")(causally later) is rejected because5000 < wall.Root cause
restore_from_file()createdMemoryNodewithout reading thehlcfield from snapshot JSONbulk_write()did not passhlcthrough toremember()gossip.receive()did not passhlcand did not update the global HLC clockFix
_parse_hlc()helper for snapshot/wire HLC normalization (with legacy fallback for pre-v0.6.0 snapshots)restore_from_file: restorehlc, call_hlc.update(), hold lock during restorebulk_write: pass throughhlcfrom row payloadsgossip.receive: apply peer HLC, skip stale/missing-hlc updates on existing keysValidation
test_hlc_snapshot_gossip.py,test_enterprise_backup.py,test_gossip.py,test_rust_brain.py,test_rust_brain_concurrency.py