myxce/.wolf/bugs/bug-1423.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

4.3 KiB

id status status_updated status_note component severity timestamp last_seen occurrences files tags related legacy
bug-1423 fixed 2026-09-24 controller hang 2026-07-09T13:58:16.000Z 2026-09-19T09:00:00Z 1
src/controller/ha.c
ha
raft
election
liveness-deadlock
vote-request
dead-peer
quorum
permanent-stall
bug-1417
bug-1418
bug-1421
true

bug-1423: 30-round sequential HA soak FAIL at round 5: post-failover submit did not get 3 acks after 5 retry…

Description

30-round sequential HA soak FAIL at round 5: post-failover submit did not get 3 acks after 5 retry attempts (15s+). Root-caused as a genuine permanent election deadlock, not a client-side false positive: ctrl-3 won PreVote and entered CTRL_ELECTING (real election, term=10) with ctrl-1 dead and ctrl-2 alive, then never showed another HA state-machine event for 2+ minutes (until the harness killed the cluster on FAIL) — stuck in CTRL_ELECTING forever. Meanwhile ctrl-2 endlessly retried its own PreVote every ~15-17s, correctly denied every time by ctrl-3 on freshness grounds, but that denial never unstuck ctrl-3's already-in-flight real election.

Environment

Not recorded (migrated from buglog.json).

Reproduction

Not recorded (migrated from buglog.json).

Root cause

raft_cb_send_vote_request (ha.c, sends the real RequestVote RPC to each peer) has two failure branches — endpoint_connect() failing and iomgr_monitor() failing — that are exactly what happens when the RPC target is a dead/unreachable peer (here, ctrl-1, killed at the start of round 5). The endpoint_connect failure branch only called the legacy handle_request_vote_reply() when c == NULL (unit-test mode) — in PRODUCTION (c always non-NULL) a connect failure to a dead peer was silently dropped with NO notification to the raft library at all. The iomgr_monitor failure branch called handle_request_vote_reply() unconditionally, including in production — but per vote_reply_dispatch's own design comment, handle_request_vote_reply is the LEGACY/ctx-done-signaling path; 'raft_on_vote_reply remains the SOLE production promotion driver' (vote_reply_dispatch calls ha_record_vote_reply + raft_on_vote_reply, NOT handle_request_vote_reply). Net effect: a candidate's vote request to a dead peer never registers as a 'reply' with the production raft library's raft_state_t.replies_received counter. raft.c's Step 6 fast-path ('all peers have replied, no quorum → become follower and retry', gated on replies_received == n_peers-1) can therefore NEVER trigger whenever any configured peer is down — with quorum=2 in a 3-node cluster and one peer dead, replies_received caps at 1 (only the live peer's real reply, if any) and can never reach n_peers-1=2. Recovery then depends ENTIRELY on the raw per-campaign election_timeout (5-10s, ha_jittered_election_delay) firing via delaymgr — in the observed failure, no election_timeout_fn trace appeared in the log at all for the full 2+ minute window, leaving the candidate permanently wedged.

Fix

Routed both raft_cb_send_vote_request failure branches (connect failure and monitor failure) through vote_reply_dispatch(ha, ectx, votes_idx, term, vote_granted=0, 0, 0) in production (c != NULL) — the exact same call a genuine vote reply makes (ha_record_vote_reply + raft_on_vote_reply), so a dead/unreachable peer now correctly counts as 'replied, not granted' immediately on connect/monitor failure instead of only via the timeout. Test mode (c == NULL) keeps the legacy handle_request_vote_reply call unit tests depend on. Added a forward declaration of the previously-file-local-only vote_reply_dispatch near the top of ha.c so raft_cb_send_vote_request (defined much earlier in the file) can call it. Verified: full controller_unit_test suite clean (755 PASS / 0 Fail, exit 0) both before and after removing temporary diagnostic logging used during root-cause; re-ran the exact failing scenario — 30-round sequential HA soak PASS (93 jobs, zero loss, all 3 nodes led) and 30-round chaotic HA soak PASS (93 jobs, zero committed divergence, zero committed job loss) — both previously hit this stall reliably (round 5 of the sequential run, 100% reproduction before the fix).

Verification

Not recorded (migrated from buglog.json).

References

  • Related: bug-1417, bug-1418, bug-1421