myxce/.wolf
Rongsong Shen bfe69b1e85 docs(raft-ha-core-safety): root-cause 7.2 round-N blocker to an ABBA dispatch deadlock; route to raft-drive-async (bug-1282)
Using gdb (SIGQUIT all-thread backtrace on the wedged nodes), nailed the round-4
blocker to a deterministic ABBA lock-order deadlock in src/lib async dispatch —
identical on both wedged survivors:

- io_worker (netio.c:672): holds ep->lock, blocks on q->lock (vtask_enq->dataq_enq)
- vdispatcher dataq_deq (dataq.c:65): holds q->lock, blocks on ep->lock via the
  vtask_eligible (vtaskmgr.c:255) -> endpoint_is_task_blocked (netio.c:1001) cb

io_worker wedges -> node stops accepting/answering PreVotes -> two restarted
survivors can't elect -> round-4 stall. The release SIGSEGV is the same ep/q race
corrupting under churn.

Defect: dataq_deq runs its match callback while holding q->lock, and the callback
takes ep->lock — inverting io_worker's ep->lock->q->lock order. Minimal fix: make
ep->busy atomic + lockless in endpoint_is_task_blocked (or io_worker drops ep->lock
before dataq_enq, or one global lock order).

Ownership: src/lib async-I/O dispatch (vtaskmgr/dataq/netio) = raft-drive-async /
core libxce, a Non-Goal of this spec. Per upstream-ownership protocol, routed to
raft-drive-async (bug-1282); 7.2 stays blocked until the dispatch lock-order is
repaired, then re-run the gate. The gate worked as designed — 7.2 must be GREEN
before raft-drive-async flips dispatch flags ON, and it caught a real dispatch
deadlock. Task 5.4 (root-cause + assign ownership) is DONE. Consensus correctness
(Phase-2/5.2/5.3) is unaffected.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019dbTHR9CsEYK9RsqmQpQpC
2026-06-30 04:18:19 +00:00
..
hooks add wolf state 2026-06-25 14:30:46 +08:00
anatomy.md add wolf state 2026-06-25 14:30:46 +08:00
buglog.json docs(raft-ha-core-safety): root-cause 7.2 round-N blocker to an ABBA dispatch deadlock; route to raft-drive-async (bug-1282) 2026-06-30 04:18:19 +00:00
cerebrum.md add wolf state 2026-06-25 14:30:46 +08:00
config.json chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
cron-manifest.json chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
cron-state.json feat(libxce-failover): foundation — per-ctx failover state, redirect-hint fields, remove orphaned retry primitive (task 1.1) 2026-06-17 00:05:41 +00:00
daemon.log commit missed 2026-06-16 15:42:43 +08:00
designqc-report.json chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
identity.md chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
memory.md chore(raft-ha-core-safety): init spec scaffold (HA-core failover-safety gate) 2026-06-27 03:16:17 +00:00
OPENWOLF.md chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
reframe-frameworks.md chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
suggestions.json chore: checkpoint all prior work for clean state 2026-06-04 13:04:16 +00:00
token-ledger.json add wolf state 2026-06-25 14:30:46 +08:00