A standby applied replicated WAL entries via apply_wal_entry (the replay/
in-memory path) which restores entities + advances applied_lsn but NEVER writes
the entry to the standby's WAL segment. The standby then ACKed (feeding the
primary's commit majority) without persisting — a Raft durability violation:
entries counted toward a commit could be lost on standby restart, and standby
WAL files stayed empty (contradicting steering: log[i] = WAL segments for every
node). This is why ctrl-2/ctrl-3 received + acked the streamed own-term NOOP yet
kept empty seg-*.wal.
Fix: new persist_wal_write_replicated(p, lsn, type, payload, len) writes the
entry to the local WAL at the PRIMARY's lsn (no lsn-reassignment), with a
self-consistent intra-segment CRC chain (the streamed entry carries no term/crc;
each node chains independently and recovery validates intra-segment), fdatasyncs
for durability, advances current_lsn = max(current_lsn, lsn+1), rotates segments,
and does NOT re-broadcast. Wired into ha_apply_single_entry as
persist(durable) -> apply(in-memory) -> ACK; on persist failure: no apply, no ACK
(a standby never ACKs an entry it didn't persist). Covers single + batch
catch-up; OPCode_replEntry has no separate apply path (allow-list only), so all
live WAL apply now persists. Dedup guard (lsn+1<=current_lsn) makes re-streams
idempotent while still ACKing.
TDD: standby write -> drop persist_t -> reopen + persist_recover replays it
(single, 3-entry crc chain, post-dedup); checkpoint/oversized rejected. Full
controller suite green under ASAN; persist_wal_async / recovery / truncation /
streamer / wire untouched.
WAL payloads:
- Job state transitions (START/FINISH/FAIL/STOP/RESUME/UPDATE etc):
wal_jobstate_t {uint64_t jobid, uint32_t state} — restores exact state flags
- Queue state (QUEUE_CTRL): wal_queuehdr_t {uint32_t status} + name string —
re-applies admin open/close/active/inactive after config queues are built
- Worker CTRL: existing [uint32_t detail][capnp xce_worker_t] unchanged
New recovery functions:
- restore_job_state(c, jobid, state): looks up job, overwrites state flags
- restore_queue_state(c, name, status): looks up queue, overwrites status
apply_wal_entry: dispatches all WAL types including job state and queue
test_repl_apply.c: weak stubs for restore_job_state/restore_queue_state
so unit test binary links without job.c/queue.c
Upgrade apply_wal_entry() from P0 static no-op stub to the real public
standby replay path:
- Reject oversized payloads (> MAX_WAL_PAYLOAD_BYTES) with -EMSGSIZE
- Skip WAL_CHECKPOINT (100) entries silently — local-only markers, never
replicated to standbys; current_lsn is NOT advanced on skip
- Skip unknown types (> WAL_ENTRY_TYPE_MAX) with WARN log and rc=0 for
forward compatibility with WAL written by newer controller versions
- Advance current_lsn to hdr->lsn+1 and update last_crc under p->lock
for all accepted known entries
- Gate restore_job()/worker_from_capnp() calls on p->cluster != NULL so
unit tests work without a full cluster wired in
- Add NULL guard returning -EINVAL for missing p or hdr
Add public declaration in persist.h with forward-declare stubs for
restore_job/worker_from_capnp in persist.c (avoids heavy cluster.h chain).
Test suite: 5 new Unity tests in test_repl_apply.c covering all branches.
Weak stubs for restore_job/worker_from_capnp in the test file satisfy the
linker without linking job.c/worker.c's heavy dependency graph.
All 5 new tests pass; full controller suite green.
