---
id: "bug-1296"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "hang"
timestamp: "2026-06-30T13:21:00.000Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/controller/ha.c"]
tags: ["raft-ha-core-safety", "election-liveness", "prevote-cross-denial", "dueling-candidates", "task-5.6", "chaotic-soak", "round-7-stall"]
related: ["bug-1281", "bug-1282", "bug-1286", "bug-1292"]
fix_commits: ["81cb09a", "74784b2"]
legacy: true
---

# bug-1296: 10-round chaotic soak FAIL at round 7: all 3 nodes in RDHUP→PreVote→timeout→repeat livelock — zero…

## Description
10-round chaotic soak FAIL at round 7: all 3 nodes in RDHUP→PreVote→timeout→repeat livelock — zero pre_vote_reply_in events (not denials, silence). ctrl-3 sent 20+ PreVote rounds with NO reply received; ctrl-1 and ctrl-2 same loop. Rounds 1-6 PASS clean (all elections + job-verification succeeded); round 7 kills ctrl-2 (term=9 primary), restarts ctrl-3 (no convergence wait — chaotic). 2 surviving nodes (ctrl-1, ctrl-3) both start PreVote; neither processes the other's request → mutual timeout → RDHUP fires again → repeat forever.

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
TASK 5.6 dueling-candidate PreVote cross-denial — DISTINCT from the earlier PreVote-WINS + real-election split-vote (which had both nodes winning PreVote then deadlocking in RequestVote). Here PreVote itself starves: each node's PreVote handler likely drops/ignores inbound PreVote requests while in its own PreVote round (no reply sent, not even denial). The task 5.6 RDHUP guard (commit 25e741d+) only prevents restarting failover while in CTRL_ELECTING — it does NOT fix the core problem where two nodes enter simultaneous PreVote rounds and each starves the other's reply. The priority stagger (bug-606) helps when 3 nodes are alive (one grants to break symmetry), but with only 2 survivors (the third restarting without convergence in chaotic mode), both deny each other and the stagger is insufficient.

## Fix
FIXED 2026-06-30 (subsumed by tasks 5.6 commit 81cb09a + 5.7 commit 74784b2). The RDHUP->PreVote->timeout liveloc was the same fixed-watchdog resonance as bug covered by 5.7: per-campaign election watchdog re-randomized to [T,2T] (Ongaro 3.4) + don't-preempt-in-flight-election (5.6). CONFIRMED by a 10-round chaotic soak: 10/10 rounds elect a new primary in a single term increment (4->13), zero term escalation, round 7+ (the old liveloc point) all clean.

## Verification
_Not recorded (migrated from buglog.json)._

## References
- Related: bug-1281, bug-1282, bug-1286, bug-1292