fix(rust_brain): preserve HLC on snapshot restore and gossip receive#40
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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>
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Bug and impact
After v0.6.0 added HLC monotonic enforcement,
restore_from_file()andgossip.receive()still assigned fresh HLC timestamps instead of preserving causal ordering from snapshots or peer events.Concrete trigger: Snapshot a node with
hlc=(5000, 10, "nodeA"), restore, then apply a causal successor writehlc=(5000, 11, "nodeA"). The write raisesTimestampRegressionbecause restore assigned a fresh wall-clock HLC — causing silent data loss in disaster-recovery and gossip replication paths.Gossip events without HLC could also overwrite fresher data by assigning a new timestamp.
Root cause
restore_from_file()constructedMemoryNodewithout reading thehlcfield from the snapshot JSON.gossip.receive()calledremember()without passinghlcfrom the event.Fix
_parse_hlc()for snapshot/wire normalization with legacy fallback_hlc.update()) on snapshot restorebulk_writeand gossip receive with stale rejectionrestore_from_fileandgc_expiredto 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