Commit Graph

3 Commits

Author SHA1 Message Date
dimgigov 39e07b542d FV-3, FV-4: 2PC coordinator crash/recovery + participant timeout
- twopc.tla: Add coordinatorLog (persistent WAL for decisions)
- twopc.tla: Add CrashCoordinator action
- twopc.tla: Add RecoverCoordinator action (reads from coordinatorLog)
- twopc.tla: Add ParticipantTimeout (only if coordinatorLog = Nil)
- twopc.tla: Add RecoveryConsistency invariant
- models/twopc.cfg: Add RecoveryConsistency to checked invariants
- Update PLAN.md, ANALYSIS.md, README.md with new metrics
2026-05-07 19:40:09 +03:00
dimgigov 19d0ff7366 feat(verify): expand formal verification to 7 specs, add versioning, CI integration
Added 3 new TLA+ specs:
- gossip.tla — SWIM gossip membership & failure detection
- deadlock.tla — wait-for graph deadlock detection
- sharding.tla — consistent hashing shard assignment

Improved existing 4 specs:
- raft.tla: added CommittedIndexValid invariant
- twopc.tla: added CoordinatorConsistency, NoDecideWithoutConsensus,
  ParticipantStateValid; increased to MaxTxnId=3
- mvcc.tla: added CommittedMustStart, CommittedVersionsUnique
- replication.tla: added AppliedLteCurrent, SemiSyncQuorum

Infrastructure:
- VERSION file (1.0.0)
- CHANGELOG.md
- ANALYSIS.md (weak spots & improvement plan)
- run_all.sh script for batch TLC verification
- CI verify job in GitHub Actions
- Updated README with new specs and properties

Total: 7 specs, 26 invariants, 11.6M states checked, 0 errors
2026-05-07 18:26:55 +03:00
dimgigov e73bfb450c feat: formal verification suite — TLA+ specs for Raft, 2PC, MVCC, Replication
Verified with TLC model checker:
- Raft: 475k states, ElectionSafety + StateMachineSafety
- 2PC: 22k states, Atomicity + NoOrphanBlocks
- MVCC: 177k states, NoDirtyReads + ReadOwnWrites + WriteWriteConflict
- Replication: 3.6M states, MonotonicLsn + AcksRemovePending
2026-05-07 15:57:33 +03:00