myxce/.wolf/bugs/bug-778.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 KiB

id status status_updated status_note component severity timestamp last_seen occurrences files tags related fix_commits legacy
bug-778 fixed 2026-09-24 controller data-loss 2026-06-19T13:40:00Z 2026-09-19T09:00:00Z 2
src/controller/persist.c:1336 (apply_wal_entry) + src/controller/ha.c ha_apply_single_entry (~1570-1588)
ha
wal
crc-chain
last_crc
apply_wal_entry
persist_wal_write_replicated
cold-restart
data-loss
bug-661
standby-replication
recovery
root-caused
bug-777
bug-661
64ab210
true

bug-778: persist_recover RECOVER_TRUNCATED: 'CRC chain break ... prev_crc=00000000 expected=' at the…

Description

persist_recover RECOVER_TRUNCATED: 'CRC chain break ... prev_crc=00000000 expected=' at the first replicated job entry on cold restart; committed jobs unrecoverable (joblist=0). ROOT CAUSE of bug-777's cold-restart data loss.

Environment

Not recorded (migrated from buglog.json).

Reproduction

Not recorded (migrated from buglog.json).

Root cause

On the standby replicated-apply path, ha_apply_single_entry first calls persist_wal_write_replicated() which correctly sets p->last_crc to the standby's SELF-computed chain crc (the stream carries no crc; the on-disk CRC chain is node-local, prev_crc==last_crc). It THEN builds a synthetic wal_entry_hdr with hdr.crc=0 and calls apply_wal_entry(), whose line 1336 p->last_crc = hdr->crc OVERWRITES the correct chain link with 0. The next replicated write computes prev_crc=(seg_offset==0?WAL_CRC_NONE:last_crc)=0 and stamps prev_crc=0 on disk. So the on-disk CRC chain breaks at the 2nd replicated entry. Invisible while live (standby serves in-memory entities; never replays its own WAL), detonates on COLD RESTART where replay_wal validates the chain -> RECOVER_TRUNCATED -> recovers only the clean prefix -> committed jobs lost + the truncated verdict drives the promotion-fence availability wedge (the other half of bug-777). NOT an fd-position/offset race (pwrite+p->lock are correct); it is shared CRC-chain state (p->last_crc) written by two paths where the logical-apply step clobbers the physical-writer's link with 0.

Fix

FIXED 2026-06-19 (commit 64ab210). apply_wal_entry is now LOGICAL entity-restore only (signature (p,type,lsn,payload,payload_len); no header); it advances the current_lsn high-water but NEVER touches p->last_crc. The CRC chain has a single owner: persist_wal_write_replicated (live) + replay_wal/persist_recover (recovery). ha_apply_single_entry drops the fabricated crc=0 header. Verified: RED->GREEN test test_replicated_apply_chain_survives_cold_restart (real ha_apply_wal_catchup_entry path, cold-replay -> RECOVER_CLEAN); controller suite 0 failures; 3-node rolling-SIGKILL soak on real ext2/3 fs 5/5 (was wedge+loss at round 3); full cold restart recovers all 6 jobs (was 0), CLEAN verdicts, normal election. Test callers updated: test_repl_apply, test_ha_role_lifecycle, test_egress_filter.

Verification

Not recorded (migrated from buglog.json).

References

  • Related: bug-777, bug-661