Commit Graph

5 Commits

Author SHA1 Message Date
dimgigov 54711d0190 FV-1, FV-13: Raft prevLogIndex/prevLogTerm + CI fix
- raft.tla: Add HasCompatiblePrefix check (prevLogIndex/prevLogTerm)
- raft.tla: Add RejectAppendEntries action for follower rejection
- raft.tla: Add conflict truncation + commitIndex/matchIndex adjustment
- raft.tla: Restore LogMatching invariant
- raft.tla: Guard AppendEntry to prevent term gaps in leader log
- models/raft.cfg: Add LogMatching to checked invariants
- .github/workflows/ci.yml: Replace container with setup-java + cache
- run_all.sh: Use -workers auto and -XX:+UseParallelGC
- Update PLAN.md, PLAN_DONE.md, ANALYSIS.md, README.md
2026-05-07 19:21:01 +03:00
dimgigov ce3b078979 docs: unified improvement plan for verification + software (53 tasks)
Covers both TLA+ specs and Nim code:
- P1: Raft prevLogIndex/LogMatching, replication data transfer,
  sharding migration (14 tasks)
- P2: backup.tla, crossmodal.tla, recovery.tla + Nim tests (14 tasks)
- P3: Liveness properties, write skew, 2PC crash recovery (12 tasks)
- P4: CI fixes, symmetry reduction, missing tests, inter-module
  integration (13 tasks)

Ties verification improvements directly to code improvements.
2026-05-07 18:39:59 +03:00
dimgigov e715454c4e docs(verify): add detailed improvement plan with 13 tasks across 4 priorities
Covers Raft prevLogIndex fix, 2PC recovery, MVCC write skew,
liveness properties, backup.tla, crossmodal.tla, CI fixes,
symmetry reduction, and Apalache migration.
2026-05-07 18:31:20 +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