---
id: "bug-1307"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "data-loss"
timestamp: "2026-06-30T15:05:00.000Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/controller/ha.c"]
tags: ["data-safety-regression", "task-5.7", "chaotic-soak", "leader-completeness-violation", "confirmed-via-soak", "committed-job-loss", "election-liveness", "bug-1296-followup", "committed-divergence"]
related: ["bug-1296", "bug-1281", "bug-1282", "bug-1286", "bug-851"]
legacy: true
---

# bug-1307: Task 5.7 election-resonance jitter (74784b2) introduced data-safety REGRESSION: 6-round chaotic…

## Description
Task 5.7 election-resonance jitter (74784b2) introduced data-safety REGRESSION: 6-round chaotic soak shows 7 committed divergences (LSNs 8,12,16,19) + 4 committed job losses (job 0-0-1782831451-1). Previous run (pre-5.7, commit 81cb09a) had ZERO divergences and ZERO job losses through 6 rounds. LSN 19 divergence is present=3 (ALL 3 members have different content at same LSN — silent divergence, textbook bug-851). Election liveness improved (all 6 rounds complete vs stalled at round 7), but the jitter defeats the election-safety balance: faster-starting node wins before catching up on committed prefix → Leader Completeness violation.

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

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

## Root cause
Task 5.7 jittered watchdog ([T,2T] randomized) lets a less-complete node start and win an election before catching up on the full committed prefix from the dead primary. With the original fixed watchdog, both survivors fired RDHUP simultaneously → cross-denied → the library's priority stagger resolved the tie safely (the fresher node won after deterministic desynchronization). With jitter, one node can fire much earlier (near T) and the other much later (near 2T) → the early node campaigns with an incomplete log → voters grant based on stale view → winner truncates committed entries it never held. The 5.3 in_catch_up release (which drops the vote-deny when the primary is dead) opens a window where a still-catching-up candidate can win — with the new jitter timings this window is hit frequently.

## Fix
CONFIRMED FIXED via live re-soak (2026-07-03): ran the exact reproducing scenario — 6-round chaotic soak (overlapping kill-the-primary, real ext4 at ~/tmp, ASAN controller binary) — that originally showed 7 committed divergences + 4 job losses. This run: 21 jobs submitted, 0 committed_divergence, 0 committed_job_loss, PASS across all 6 rounds (terms 3->9, all 3 nodes rotated through primary). Matches the earlier circumstantial evidence (raft-ha-core-safety Phase 5 fully complete + prior soak-clean sessions) with a fresh, direct confirmation run — no residual doubt.

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

## References
- Related: bug-1296, bug-1281, bug-1282, bug-1286, bug-851