chore(buglog): log bug-1878 (ctrlstatus appliedLsn 0 on primary) and bug-1879 (cold boot ~10 s without primary)

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

2026-09-28 07:12:31 +00:00

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bug-1879: fresh HA cluster has no primary for ~10 s: first election lost, not retried until liveness timeout

Description

Observed:

[14:47:32,960] ctrl-1 HA FSM: -> CTRL_ELECTING (async, n_peers=3)
[14:47:32,962] ctrl-1 HA FSM (raft): -> CTRL_STANDBY (term=1, first_boot=1)
[14:47:32,962] ctrl-1 myapp_run: CTRL_STANDBY — waiting for primary to connect and push config
[14:47:44,368] ctrl-1 WARN liveness_poll_fn: HA: liveness poll: no primary activity for 11s (timeout=10s) -> failover
[14:47:44,661] ctrl-1 HA FSM (raft): -> CTRL_PRIMARY (term=2, first_boot=0)

(pc13v; locally ctrl-2/ctrl-3 log ha_start_election_async: no local config (tag=0, n_peers=3) — participating as voter only) Expected: a fresh cluster elects its primary as soon as a quorum of nodes is up (about a second with start-all.sh's 0.5-1 s stagger). Impact: every cold start of an HA cluster has no primary for about 10 s (the standby liveness timeout): no job submission, config push or scheduling in that window, a spurious failover WARN, and the cluster always starts at term 2. Also the cause of the 10 s of standby 'waiting for config' seen in bug-1876. Found by: user reading ctrl-1's boot log and ctrlstatus (electedTerm 2) on pc13v after the bug-1872..1877 retest

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 @ 44173f74 (controller unchanged since; pc13v ran 4c134127)
Deployment: local 3-node HA (localhost:9991-9993, src/tools/deploy-ha.sh, nodes started 1 s apart by start-all.sh, xcecd_virtual) on this dev host; first seen on pc13v: NixOS 26.05, kernel 6.18.33, glibc 2.42-47, debug build, 3-node HA (ctrl-1..3, localhost:9901-9903) + scheduler + apiserver + real root xcecd, /tmp/xce-ha-deploy, 2026-09-28 14:47 +0800

Reproduction

/xce-deploy-ha (fresh deploy; only ctrl-1 gets the cluster config)
scripts/start-all.sh (starts ctrl-1, ctrl-2, ctrl-3 about 1 s apart)
grep -E 'CTRL_|liveness poll|voter only' logs/ctrl-*.log: ctrl-1 goes CTRL_STANDBY within ~50 ms, ctrl-2/3 are voter-only, and the first primary appears ~10 s later at term 2

Frequency: 2/2 cold starts (pc13v 14:47 and the local run 07:10, 2026-09-28)
Evidence: logs quoted above; the local deploy's logs were in /tmp/claude-1000/xce-deploy-coldboot/logs (not kept)

Root cause

Established from both runs: ctrl-1, the only node with a local config, starts its term-1 election before its peers are running, cannot reach a quorum, and drops to CTRL_STANDBY ("waiting for primary") within ~50 ms. ctrl-2 and ctrl-3 have no local config, so ha_start_election_async() makes them voters only -- they never stand. That is by design (confirmed by the user, 2026-09-28): on a cold boot only the node holding the initial configuration (ctrl-1) may become primary, so the retry has to come from ctrl-1. Nothing starts another election until ctrl-1's standby liveness poll (10 s) treats the missing primary as a failure and runs PreVote, which it then wins at once.

Unconfirmed: why the lost first-boot election leaves ctrl-1 in CTRL_STANDBY with only the 10 s liveness poll as a retry, instead of retrying after a short (randomized) election timeout as Raft does for a candidate that fails to win -- to be read in ha.c's raft_cb_become_follower()/first_boot path and myapp_run().

Fix

Proposed: when the config-holding node loses its first-boot election for lack of quorum, keep it a candidate and retry its own election after a short randomized election timeout (well under the 10 s standby liveness timeout) until it wins or another primary appears -- instead of settling into CTRL_STANDBY with only the liveness poll as a retry. Nodes without a config stay voters only.

Verification

Test: TODO: name + file; RED before the fix, GREEN after
Suites: TODO: suite results and build profile
Live: TODO: soak/deploy run, or n/a and why

References

Related: bug-1876 (the standby 'waiting for config' warnings this caused), bug-606 (PreVote staggering)

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