Fixes the two defects a malformed probe exposed on the live cluster, plus the
coverage gap that let a stale assertion survive the same day it was falsified.
TASK 17 — validate before the WAL append. A 128-dim vector against a 1536-dim
slot was appended to the WAL FIRST, then validated, then answered 500 — so an
already-durable, unapplicable record shipped to both followers, halted both
receivers, and put shard 1 into a quorum-write outage. Validation now runs before
the append and returns 400 via invalid_input; nothing enters the log.
`storage::vector::validate_dimensions` is now the single comparison, replacing an
inline duplicate of the same rule in lifecycle/ops.rs:57-62 — two copies of a
dimension check drift, and the apply-path copy is the one that halts replication
when it disagrees.
The receiver's halt-vs-skip decision is now explicit instead of "halt on
anything". A record whose failure is deterministic and node-independent (schema
width) is skipped, counted on blobs_apply_failed_total and ERROR-logged, so the
frontier advances; a record that could become applicable after a binary upgrade
(unknown batch kind, capability skew) still halts, because skipping那 would
silently drop replicated data. Both branches are proven reachable by tests.
TASK 18 — the reseed latch outlived its discharge. A node hosting 3 shard groups
latched a marker per group but discharged on a single seqno, so two latches meant
permanent 503 on a node whose every shard read lag 0 — it hit all three pods
during the roll and each needed a manual delete. Gaps are now tracked per group
in a ReseedGapSet and cleared on evidence about themselves; a REFUSED
reseed_self_restart re-evaluates every 15s instead of waiting for a latch that
never arrives. /health's cause ladder was also lying: it printed "joiner boot not
yet converged" for a node whose groups had all converged, because the fallback
asserted a state it never tested. It now names the outstanding gaps, gained the
decommissioned-by-signal arm that is_ready checked but the ladder did not, and
its terminal arm says "reason unavailable" rather than inventing one.
COVERAGE — 14 of 23 integration suites were run by NO pipeline. Not theoretical:
cluster_routes still asserted the wire fabrication removed hours earlier
(applied_events == 0 with a lag derived from it) and nothing caught it because
nothing ran it. cluster_sharding (dense-rank, /sharded/* opt-in), vector_search
(distance contract) and cluster_poison_embedding (task 17's own gate) were in the
same position, so those guards would have rotted identically. Every suite now has
a runner: 8 in-process ones in a new `fast-suites` push step (measured 71s, runs
FIRST so a cheap failure precedes the 6.5-min gate), 6 multiproc ones in the
nightly. All 23 scheduled; all 4 never-before-run heavy suites verified passing
before being scheduled.
Also fixes cluster_chaos.rs:329, which the nightly's FIRST EVER run caught 13
minutes in — it demanded an unreachable peer report worst-case lag, i.e. it
required the fabrication task 04a deleted.
Verified: fmt clean; clippy 72 vs 73 baseline (one FEWER, zero added, measured on
touched trees at 431340f); lib 2115 passed; all 8 fast suites green;
cluster_chaos 5, cluster_sharding 5, cluster_poison_embedding 1,
cluster_cross_shard_reads 2, cluster_graph_persistence 1, cluster_multiproc 5,
cluster_e2e 2; doc-guard OK.
ack=quorum gates replicated writes on a majority of the replica set durably
holding them: followers push their durably-applied frontier (ReportApplied,
once per apply round, decoupled from ship acks), the leader folds frontier
reports + ship-ack hints + heal resumes into a leadership-scoped CommitIndex
(k-th-largest durable mark), and handlers await it through an async
watch-channel bridge (zero parked threads per waiter). Honest timeouts:
retryable 503 naming the laggards; x-tidal-seq on every cluster write.
Follower blob applies are batched under group-commit fsyncs (22x seeding).
Exit gate: 167/167 leader-SIGKILL kill points, zero acked-write loss.
Seven-dimension review pass (all confirmed findings fixed):
- WAL blob drain now ABORTS on the first write failure instead of reusing
the failed seqno mid-drain (a torn record buried mid-segment would
truncate every later acked record on replay)
- apply_replicated_blobs waits every staged append even after a mid-batch
failure, parses metadata once, and moves records into Arcs shared with
the WAL writer (no deep clone per record on the follower apply path)
- CommitIndex: zero-peer fast path now respects demotion (active checked
under lock before the single-replica return), k-th-largest uses
select_nth over a reused scratch buffer
- await_quorum: re-reads the index once after the deadline fires (no false
503 for a write that committed in the race window), warns when the
commit-watch bridge dies outside shutdown, zero-peer path checks active
- notify_applied report failures: WARN on the first failure of a streak,
INFO on recovery (a silently stalling frontier reads as unexplained
quorum 503s); receiver skips re-notifying unadvanced frontiers
- x-tidal-deduplicated: 1 marks dedup-suppressed signal writes (relayed
through forwards) so durability cursors can tell dedup from no-seqno
- docs: 167/167 kill-point record corrected in CHANGELOG; rolling-upgrade
order (leader first — a pre-m11p3 leader silently downgrades quorum
requests to leader-ack) in CHANGELOG + runbook §8; monitoring note for
report-loss diagnosis on the quorum-timeout alert
Verified: workspace clippy -D warnings (incl. cluster-e2e targets), full
tidaldb/tidal-net/tidal-server/tidalctl suites green, tier-3 multi-process
quorum suite green (8/8 kill points, zero acked loss, partition gate/recover).
m11p1 — decoupled ack/ship path: staged writes (seqno+WAL+relay-push,
microseconds) separate from group-commit fsync; ShipQueue batches+windows
outbound segments; receiver coalesces inbound chunks before applying.
Adds first tidaldb_cluster_* metrics.
m11p2 — leader WAL is now THE replicated log: fsynced batches feed a
bounded WalShipFeed and ship byte-identical to followers; WAL seqnos
survive restarts (relay-reset hazard gone). Item metadata and embeddings
journal kind-1/2 blob records on the same stream as signals; the m8p10
HTTP broadcast is deleted. StreamSegments catch-up is follower-pulled via
server-streaming RPC, triggered on gap detection, follower boot, and
leader heal nudge. Promote carries a stream baseline so peers skip
pre-stream history.
Splits monolithic cluster.rs into tidal-server/src/cluster/ modules. Adds redeliver-missed
relay, bounded HLC drift, lag tracking, and reconcile idempotence. Five new tier-3 test suites
(chaos, lifecycle, multiproc, region, routes, runbook) all green. Docs, CHANGELOG, and ROADMAP
updated with G4/G5/G6 known gaps.
