dimgigov
19d0ff7366
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
2.1 KiB
2.1 KiB
BaraDB Formal Verification Changelog
[1.0.0] — 2026-05-07
Added
- raft.tla — Raft consensus: ElectionSafety, LeaderAppendOnly, StateMachineSafety, CommittedIndexValid
- twopc.tla — Two-Phase Commit: Atomicity, NoOrphanBlocks, CoordinatorConsistency, NoDecideWithoutConsensus, ParticipantStateValid
- mvcc.tla — MVCC / Snapshot Isolation: NoDirtyReads, ReadOwnWrites, WriteWriteConflict, CommittedMustStart, CommittedVersionsUnique
- replication.tla — Async/Sync/Semi-sync Replication: MonotonicLsn, AcksRemovePending, PendingAreKnown, AppliedLteCurrent
- gossip.tla — SWIM-like Gossip Protocol: AliveNotFalselyDead, IncarnationMonotonic, DeadConsistency
- deadlock.tla — Deadlock Detection: GraphIntegrity, NoSelfLoops
- sharding.tla — Consistent Hashing Sharding: VirtualNodeMapping, NodeAssignmentConsistency, VnodeOrdering
Improved
- raft.tla: Increased from 6 invariants (TypeOk included) to 5 verified properties with cleaner semantics
- twopc.tla: Added 3 new invariants (CoordinatorConsistency, NoDecideWithoutConsensus, ParticipantStateValid), increased model to MaxTxnId=3
- mvcc.tla: Added CommittedMustStart, CommittedVersionsUnique; removed incorrect ReadStability
- replication.tla: Added AppliedLteCurrent, SemiSyncQuorum; simplified SyncDurability for model checking
Infrastructure
- Added
VERSIONfile (v1.0.0) - Added
CHANGELOG.md - Added
run_all.shscript for batch TLC verification - Added CI job (
verify) for automated TLA+ model checking in GitHub Actions
Model Checker Configs
| Spec | Model Bounds | States Checked | Properties |
|---|---|---|---|
| raft | 3 nodes, MaxTerm=3, MaxLogLen=3 | 475,972 | 4 |
| twopc | 3 participants, MaxTxnId=3 | 2,125,825 | 5 |
| mvcc | 2 keys, 2 values, MaxTxnId=2 | 177,849 | 5 |
| replication | 3 replicas, MaxLsn=3, MaxSyncCount=2 | 3,687,939 | 4 + 1 temporal |
| gossip | 3 nodes, MaxIncarnation=3 | 1,257,121 | 3 |
| deadlock | 5 txns, MaxEdges=8 | 3,767,361 | 2 |
| sharding | 3 shards, 2 nodes, 5 vnodes | 186,305 | 3 |