fix(rust_brain): preserve HLC on snapshot restore and gossip receive#28
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restore_from_file dropped hlc fields added in v0.6.0, assigning fresh timestamps on restore. Post-crash causal writes and gossip replays with pre-crash HLC were rejected (silent data loss), while gossip events without HLC could overwrite fresher data. - Add _parse_hlc() for snapshot/wire normalisation with legacy fallback - restore_from_file: restore hlc and advance global _hlc per node - bulk_write: pass through hlc from row payloads - gossip.receive: apply hlc, reject stale updates, skip missing-hlc overwrites on existing keys - Tests: snapshot HLC round-trip, gossip stale/new/missing-hlc cases Co-authored-by: Daniel <DJLougen@users.noreply.github.com>
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Bug and impact
Critical data loss after snapshot restore. v0.6.0 added Hybrid Logical Clock (HLC) monotonic enforcement on writes.
restore_from_file()did not restore stored HLC timestamps — it assigned fresh process-local HLCs instead. After disaster recovery, any gossip replay or causal successor write carrying the pre-crash HLC was rejected withTimestampRegression, silently dropping updates.Gossip overwrite risk.
gossip.receive()also ignored incoming HLCs, so stale gossip without HLC could overwrite fresher data on existing keys.Root cause
restore_from_file()rebuiltMemoryNodewithout thehlcfield from the snapshot payload.bulk_write()did not pass throughhlcfrom row dicts.GossipProtocol.receive()calledremember()withouthlc,ts_ns, oredges.Fix
_parse_hlc()helper for wire/snapshot normalization (with legacy fallback fromts_ns).restore_from_file()and call_hlc.update()so the process clock stays ahead.hlcthroughbulk_write().Validation
TimestampRegression.(5000, 10, 'nodeA')preserved; successor write accepted.37 passedacrosstest_enterprise_backup,test_gossip,test_rust_brain,test_rust_brain_concurrency.