docs(buglog): bug-1683, bug-1485, bug-1725 fixed with corrected root causes; log bug-1913

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

2026-10-03 14:51:27 +00:00

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bug-1913: after a late-joiner election the primary cannot commit client writes for ~2 heartbeat cycles

Description

Observed:

repl_broadcast: no standbys registered ... not replicated
...
WAL NACK from standby lsn=2 ... marking catch-up
repl_wait_majority_ack: timeout ... OP_upgradeConfig rejected (status=-110)

In some elections the vote connections are not converted into standby channels (raft_cb_become_leader), so both standbys register later through on_standby_connected (ha.c ~9643-9660). ha_arm_own_term_gate (ha.c ~5178) has already appended the own-term WAL_NOOP (lsn 1) while no standby was registered (repl.c ~306-311), and repl_add_standby does not resend it. Catch-up then runs from the 3 s heartbeat, one action per standby per cycle (config push first, WAL stream on the next cycle), so committed_lsn stays 0 for ~6 s. Any client write in that window (e.g. OP_upgradeConfig) is NACKed by both standbys and fails with -ETIMEDOUT after the 500 ms majority wait.

Expected: a newly elected primary commits its own-term no-op, and so accepts client writes, promptly after its standbys register, not two heartbeat cycles later. Impact: for ~6 s after such an election every client write is rejected with -110 (fail-loud, no data loss, no false success). Clients retry, but tests and operators see spurious failures right after failover (the root cause of bug-1485's versionTag=0 flake). A fix must respect the async-I/O rules (no blocking on the delaymgr/heartbeat path; streaming offloaded) in .kiro/steering/ha-async-io.md. Found by: test (root cause of bug-1485)

Environment

OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
Build: asan (xce.build)
Code: scheduler-framework @ 91782e40-dirty
Deployment: local 3-node HA (xceadmin live e2e fixture), CPU-loaded sandbox (40 busy loops on 32 cores) makes late-joiner elections frequent

Reproduction

Start a 3-node HA cluster (e.g. the live_ha_cluster fixture in src/xceadmin/tests/test_e2e_live_ha_push.py) under CPU load.
In the primary log, find an election with no "promoted" standby channels and a later "repl_add_standby"/late registration; push a config (xceadmin config push ... --controller <primary>) within ~6 s.
The push fails with controller returned status -110; the log shows the NACK and majority-ack timeout above.

Frequency: 7/28 runs of the HA push test under 40-spinner CPU load, 0/6 idle (2026-10-03); all 7 failures were late-joiner elections.
Evidence: not kept (scratchpad loop logs from the bug-1485 investigation).

Root cause

TODO: required for fixed/partial

Fix