myxce/.wolf/bugs/bug-661.md
Rongsong Shen d26ff8870d
feat(buglog): one Markdown record per bug, checked against a record standard
The buglog was one 27K-line JSON file whose fields covered only symptom,
root cause and fix, as free text: 2% of entries named the code version a
bug was found on, 12% the build profile, 36% a way to reproduce, and 58% of
the file was OpenWolf hook auto-detections ("Missing guard clause",
"Function not marked async" on .md files).

- .claude/skills/buglog/bug-record.md: the record standard. Eight
  sections (Summary as the title, Description, Environment, Reproduction;
  Root cause, Fix, Verification, References once fixed), each with the
  content it must contain -- e.g. Environment needs the OS, the libc the
  failing binary loads (from its ELF interpreter: glibc 2.42 in the nix
  shell vs 2.40 on the host), toolchain, build profile and commit.
- .wolf/bugs/<id>.md: 500 records migrated from buglog.json; every field
  verified to round-trip. They carry legacy: true and an explicit "not
  recorded" where the old log had no such field; component derived from
  file paths, severity from keywords (else unknown), fix_commits from
  hashes in status_note/fix that git resolves (91 of 463 fixed).
- .wolf/buglog-archive.json: the 710 hook auto-detections, verbatim.
- .wolf/buglog.json is now an index generated from the records, keeping
  the fields OpenWolf's hooks and `openwolf bug search` read.
- scripts/buglog.py rewritten: new (template + Environment collected from
  the machine and --binary), check, status (refuses a status the record
  doesn't support; fixed needs Root cause, Fix, Verification and
  --commit hashes git resolves), note, recur, set, show, list, triage,
  env, index. 29 unittest cases in scripts/tests/test_buglog.py.
- scripts/git-hooks/pre-commit runs `check --staged`: incomplete staged
  records, a legacy record hand-changed to fixed without the fix-time
  sections, a new record claiming legacy: true, or a stale index refuse
  the commit.
- scripts/gitea-sync.py reads the records: issue body = the record's
  sections plus linked fix commits (origin remote, GITEA_COMMIT_REPO to
  override), and a body hash so an issue's text is refreshed when the
  record changes.
- bug-1866 rewritten to the full standard as the worked example.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-28 03:40:11 +00:00

3.5 KiB

id status status_updated status_note component severity timestamp last_seen occurrences files tags related fix_commits legacy
bug-661 fixed 2026-09-24 f139e1c0 controller data-loss 2026-06-17T23:30:00Z 2026-09-19T09:00:00Z 2
src/controller/persist.c
src/controller/commit.c
src/controller/repl.c
controller
ha
durability
fsync
wal
commit-engine
data-loss
failover
leader-completeness
promotion-fence
async-fsync
deterministic-repro
wal-sync-ms
bug-339
bug-447
bug-396
f139e1c0
true

bug-661: 3-node failover test lost committed jobs: 7 earliest JobIds (WAL LSN<=20), majority-ACKed and…

Description

3-node failover test lost committed jobs: 7 earliest JobIds (WAL LSN<=20), majority-ACKed and survived first failover, permanently gone after a restarted node with near-empty WAL won election. joblist dropped from 10 to 3.

Environment

Not recorded (migrated from buglog.json).

Reproduction

Not recorded (migrated from buglog.json).

Root cause

'committed' does not imply 'durable'. WAL fsync is asynchronous (persist.c:173 fsync_worker, timer wal_sync_ms); persist_append and the standby WalAck path do NOT fdatasync before ACK. commit_on_ack (commit.c:303) advances committed_lsn on majority ACK = OS page cache only, durable on zero disks. On kill+restart, killed nodes lose the not-yet-fsynced tail; persist_recover hits CRC break at zeroed region (prev_crc=00000000, offset 40) and truncates replay to ~0 entries, yet the hollow node stays eligible, wins election under degraded required=1 quorum (PreVote+freshness gate cannot fence it because the committed entries were durable on nobody), self-promotes advertising committed_lsn=21 over an empty job table, and the node holding the real data converges DOWN. Violates Leader-Completeness assumption (majority-ACK != durable-on-majority) in src/controller/CLAUDE.md.

Fix

NOT YET FIXED. Discovery -> new spec ha-commit-durability (Path C, brief written). R1 fsync-before-ACK (standby fdatasync before WalAck, primary self-count only after local fdatasync, committed_lsn advances only on durable majority, group-commit to bound latency). R2 promotion fence (WAL CRC/replay failure => ineligible to lead until caught up, FATAL not silent truncate; never lead below known committed high-water even under degraded quorum). Live E2E reproduces via xce_test jobsub + primary kills on /xce-deploy-ha. DETERMINISTIC REPRO (task 1.3, 2026-06-18): bash src/tools/test-commit-durability.sh --deterministic launches the cluster with --wal-sync-ms 30000 (plumbed via deploy-ha.sh start.sh $* passthrough, EXTRA_CTRL_ARGS) so the primary's fsync_worker never fires in-window -> every committed entry is page-cache-only on the primary (majority_candidate_locked counts cap=highest_appended_lsn=current_lsn-1, NOT durable). It then drives rolling PRIMARY kills (each right after committing to that primary) + restart, so hollow nodes re-lead. RED CONFIRMED: 6-round run lost the 3 EARLIEST committed JobIds permanently (rounds 4 and 6 + final check), Results 5 passed/3 failed, exit=1 — matching the incident signature (earliest jobs gone). NOTE: a single double-kill does NOT repro — this codebase enforces strict majority (lone survivor will NOT self-elect: log shows 'no single-voter primary within 40s'); loss needs the ROLLING/term-accumulating path the incident used. Evidence log: dur-det-run.log in worktree.

Verification

Not recorded (migrated from buglog.json).

References

  • Related: bug-339, bug-447, bug-396