---
id: "bug-1028"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "unknown"
timestamp: "2026-06-23"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 2
files: ["src/controller/ha.c (ha_dispatch_repl_action_for_standby / catch-up streamer on the NEW term)", "config_repl.c (ha_stream_wal_to_standby)", "persist.c (standby apply) -- NOT data loss; committed prefix is byte-identical on disk (walcompare OK)."]
tags: ["failover", "availability", "liveness", "catch-up", "new-primary", "not-serving", "ha-commit-durability", "NOT-FIXED", "FIXED", "catch-up", "ha_stream_wal_to_standby", "persist_entry_term", "logOk"]
related: ["bug-828", "bug-854", "bug-795", "bug-991"]
legacy: true
---

# bug-1028: Post-failover AVAILABILITY: after a clean failover the new primary never becomes available to…

## Description
Post-failover AVAILABILITY: after a clean failover the new primary never becomes available to serve clients (wait-primary times out). New primary logs 'ha_dispatch_repl_action_for_standby: standby[0] lsn=5 < committed_lsn=6 -> stream WAL batches' every ~3s indefinitely; the lagging standby never advances to the new primary's own-term tip, and the client cannot reach a serving primary. Surfaced only AFTER bug-828 was fixed (the committed-job-loss previously masked this by failing the harness earlier at walcompare).

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

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

## Root cause
ha_stream_wal_to_standby (config_repl.c) stamped each streamed entry's term and the AppendEntries prev_log_term from raw on-disk hdr.term (the WAL header), but the standby's logOk (raft_on_append_entries_request) and the library's own send path both source terms from persist_entry_term (the authoritative in-memory per-LSN term index), which maps a legacy-0 entry to WAL_LEGACY_TERM(1). So for a legacy-0 predecessor entry (raw hdr.term==0), the streamer sent prev_log_term=0 while the standby computed its own term as 1 → logOk mismatch → the new-term NOOP (the post-promotion first entry) is perpetually rejected → no WalAck → applied_lsn stuck at pre-promotion value → the heartbeat state report advertises the stale lsn → the primary re-streams [lsn+1..committed] every heartbeat cycle. The committed prefix stays byte-identical because only term metadata diverges, not data. CONFIRMED: baseline walcompare shows committed-prefix DIVERGENCE (term mismatch → CRC-chain breaks on some members); with the fix the committed prefix is IDENTICAL.

## Fix
FIXED (2026-06-23). ha_stream_wal_to_standby gained a const persist_t* p parameter (decl in config_repl.h). All three hdr.term source sites in the streamer body (entry->term, prev_streamed_term on the main path, prev_streamed_term on the OOM-skip path) replaced with p ? persist_entry_term(p, hdr.lsn) : hdr.term (NULL-p path for count-only unit tests). Callers (ha_dispatch_repl_action_for_standby in ha.c, catchup_stream_range in config_repl.c) pass &c->persist. Unit test (test_wal_stream_term_from_index_not_raw_hdr) legacy-appends LSN 1 at term 0 + LSN 2 at term 3; streams standby_lsn=1,committed=2; asserts streamed entry term==3 and prev_log_term==WAL_LEGACY_TERM(1). RED→GREEN proven (Expected 1 Was 0 → PASS). Live: standby converge + committed prefix identical.

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

## References
- Related: bug-828, bug-854, bug-795, bug-991