fix(rust_brain): preserve HLC on restore and gossip receive#18
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v0.6.0 switched monotonic enforcement from ts_ns to HLC but two call paths were not updated: - restore_from_file() dropped HLC from snapshots, assigning fresh clocks that blocked legitimate post-restore replication and broke causal order. - gossip.receive() omitted HLC, so late-arriving events got a fresh local timestamp and could overwrite newer data on the same key. Restore now round-trips HLC (with ts_ns fallback for legacy snapshots) and advances the process clock. Gossip applies remote HLCs via update_hlc(), rejects stale writes, and skips unordered updates to existing keys when no HLC is present. Regression tests added for both paths. 190 tests pass. Co-authored-by: Daniel <DJLougen@users.noreply.github.com>
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Bug and impact
v0.6.0 (
07a1c75) moved monotonic write enforcement fromts_nsto Hybrid Logical Clock (HLC), but two distributed-data paths were not updated:restore_from_file()dropped HLC — Snapshots include HLC into_dict(), but restore assigned fresh clocks viaMemoryNodedefaults. After disaster-recovery restore, legitimate replication writes with causal successor HLCs were rejected (TimestampRegression), breaking cluster sync. Pre-v0.6.0 snapshots that only hadts_nsare handled via a synthetic HLC fallback.gossip.receive()omitted HLC — Late-arriving gossip events received a fresh local HLC on apply, so stale remote writes could overwrite newer local data on the same key (confirmed with a concrete repro).Root cause
HLC enforcement was added to
remember()without updating snapshot restore or gossip ingestion to propagate timestamps.Fix
restore_from_file()restores HLC from snapshot (list→tuple), falls back tots_ns-derived HLC for legacy snapshots, and advances the process HLC.gossip.receive()callsupdate_hlc(), passeshlc/ts_nstoremember(), rejects stale HLC writes, and skips unordered updates to existing keys when no HLC is present.bulk_write()passes throughhlcwhen provided.Validation
tests/test_enterprise_backup.pyandtests/test_gossip.py