M0-M12 are shipped and the HA cluster runs in production on k3s, so the
pre-release disclaimer no longer describes the project. Removes it from the
canonical doc set and corrects the readiness text that had gone stale.
- README.md: replace the "Pre-release / not yet recommended for production"
banner with a production-ready statement; drop "(experimental)" from the
cluster status bullet; state the post-1.0 versioning posture (additive in
minor releases, breaking changes get a documented migration path).
- CLAUDE.md / QUICKSTART.md / docs/guides/server-deployment.md /
docs/runbooks/cluster.md: same withdrawal; reframe the cluster opt-in as a
guard against standing up a multi-node fabric by accident rather than a
readiness warning.
- CHANGELOG.md: record the stability posture under [Unreleased], superseding
the historical 0.1.0 "no stability guarantees" note (left intact as history).
- k8s/statefulset.yaml: the "NOT production HA, tracked as m8p10" comment was
stale (m8p10 shipped); point at k8s/cluster/ for the HA deployment instead.
Also corrects text that was factually wrong since m11p3/m11p4: the
multi-process cluster gate, its CLI help, and the served OpenAPI description
all still claimed quorum-ack writes and automatic failure detection did not
exist. They do.
Historical records (docs/reviews/, docs/profiling/, past CHANGELOG entries,
the kubernetes.md rc7 fix note) are left unchanged.
Verified against a running binary, not just the build: the opt-in gate's
refusal message, the startup WARN, /health 200, and the served
/openapi.json description all carry the new text. cargo fmt clean; clippy
-D warnings clean on tidaldb and the tidal-server lib; 1943 engine + 155
server lib tests pass; scripts/check-docs.sh OK.
Claude-Session: https://claude.ai/code/session_01QdqSDw1tUhK1JT9Pb1vryP
Fixes a regression the reseed-loop fix (c8ea05b "Fix 1") introduced: a node
that seed-joins and converges via a SNAPSHOT INSTALL never auto-promotes
Learner -> Voter. It catches up fully (applied == leader frontier, lag 0) but
sits a Learner forever; `mp_seed_join_snapshot_catchup` caught it (base
580142d passes, c8ea05b on fails — bisected).
Root cause: the leader's durable per-peer `learner_mark` (which the
auto-promotion gate reads: `flushed - learner_mark <= learner_promote_lag`)
advances ONLY from a follower frontier-report, which the receiver emits AFTER
applying a streamed event. Before Fix 1 a joiner seeded its frontier from
`last_wal_seq()` (0 on the empty WAL a checkpoint restore leaves), so it
re-pulled the whole log from seqno 1 and THOSE stream applies emitted the
reports that advanced `learner_mark`. Fix 1 seeds the frontier to
`snapshot_seq` to stop the prod reseed loop, so the leader has nothing to
ship, no stream applies, and the joiner never tells the leader it is caught
up.
Fix: in the m12p5 heartbeat idle-readiness drive
(`note_leader_frontier_for_readiness`) report this node's caught-up frontier
back to the leader via the existing `ReportApplied` channel. The heartbeat
flows on an idle cluster and carries the current term, so the report is both
recurring (survives the join/registration race) and term-correct (the
term-checked `update_peer_for_term` fold accepts it — a boot-time report
stamped term 0 does not). SCOPED to a Learner: a Voter's frontier already
reaches the leader via ship-acks and DOES feed `compute_commit`, so folding
one off the heartbeat could perturb the same-term commit gate (Raft fig-8); a
learner mark never feeds `compute_commit`, so this is provably commit-safe.
`notify_applied` dedups, so a steady follower never spams.
Verified: mp_seed_join_snapshot_catchup PASS (joiner promotes, 4-voter
quorum); safety preserved — mp_quarantined (divergent quarantine+reseed, no
wipe), mp_graceful_rolling_restart_under_load_no_reseed (0-reseed), the
failover oracle (no false quarantine), tidal-server lib 154/154, engine
durability 4/4, clippy -D clean. The 5600-item voter-reseed e2e are inert to
this Learner-scoped change (host RAM cannot run them locally; verified live).
The rc4 live deploy converged tidaldb-2 but through ~4 needless self-restarts: a
caught-up shard whose persisted frontier is briefly behind the leader's ADVANCED
baseline (the leader kept writing while the node was down) latches a
snapshot_required marker on the first heartbeat's decide_join, which ARMS a
self-restart. The shard then catches up via the stream — note_term_joined
journals the durable term marker and clear_stale_reseed_marker_if_caught_up
clears the marker — but the already-armed self-restart still fires (Fix 3 defers
it 5s, then exits). The reboot reseeds NOTHING (the leader answers needed=false
for a caught-up shard), so it is futile and flaps readiness.
Fix: gate the self-restart on the marker still being LATCHED at the fire point —
re-check after the (slow) quorum poll and again in the Fix 3 deferred timer
(where the catch-up actually completes within the grace). A marker that healed
via stream catch-up aborts the restart; only a marker that CANNOT self-heal (a
genuine compacted gap, still latched) proceeds to reseed at the next boot. This
converges a caught-up shard IN PLACE (no reboot), while preserving the real
reseed for a genuinely-behind shard.
Verified: tidal-server clippy -D warnings clean; the cluster_reseed e2e
(quarantine reseed still fires, rolling restart still 0-reseed) and the live
rollout confirm the genuine-reseed path is unaffected.
The live rc3 deploy on tidaldb-2 (which hosts all 3 shards) revealed a second
loop the install-only term-marker synthesis (prior commit) does not reach: a
shard that was reseeded in an earlier loop iteration has an EMPTY WAL
(tail_term=0) but a frontier that already COVERS the leader's baseline. On the
next boot the leader answers needed=false (its WAL covers the frontier), so the
shard never installs, never gets a synthesized term marker, and decide_join —
comparing (tail_term, frontier) with tail_term first — classifies it
ReseedRequired forever. tidaldb-2 went 35 CrashLoops -> shard 2 converged via Fix
2 but shards 0/1 kept looping (restarts still climbing, ready=false).
Two complementary fixes:
- decide_join: in the `own < prev_log` arm, a frontier at/above the leader's
baseline is CAUGHT UP (it holds every committed entry, only the term-marker
record is missing) -> Clean, not a futile reseed. A frontier short of the
baseline is genuinely behind -> ReseedRequired. Divergence is unaffected: a
future-term marker and an un-replicated leader-acked suffix both quarantine
BEFORE this arm, so the frontier-covers-baseline Clean never reaches a
divergent node (verified: mp_quarantined still quarantines).
- note_term_joined: when the WAL-tail term is stale on a clean join, durably
append the kind-3 term marker (guarded, so once per stale term — never a WAL
write per heartbeat), generalizing the install-boot synthesis to caught-up
shards that never install. Falls back to the in-memory fold on append failure
(decide_join's frontier arm keeps the node Clean regardless).
Tests: decide_join now asserts caught-up->Clean, behind->ReseedRequired,
divergent->Quarantine. Verified: cluster_reseed 4/4 (rolling restart 0-reseed x2,
quarantine reseed, failover oracle — no false quarantine), tidal-server lib
154/154, engine durability 4/4.
Root cause: after a checkpoint-based snapshot install the engine WAL is empty,
so wal_term_mark() reports tail_term=0. decide_join compares (tail_term, frontier)
lexicographically — tail_term FIRST — so 0 < leader_term classifies the reseeded
shard ReseedRequired on EVERY boot regardless of the correctly-seeded frontier,
re-latching the marker and self-restarting forever. Observed live on tidaldb-2:
30 CrashLoopBackOff restarts, leader tidaldb-1 term 5, baseline=536647, the
frontier seeded correctly (from_seqno=536647) yet the loop persists because the
(tail_term, frontier) compare never reaches the frontier.
Fix 1 (already in tree): seed the post-open frontier from sentinel.snapshot_seq,
not last_wal_seq() (which a checkpoint restore leaves at 0).
Fix 2 (loop-breaker): durably synthesize the artifact's kind-3 TERM_MARKER WAL
record in the post-open reseed seed, at the artifact's captured term + the
reseed-leader region (threaded through an extended 18-byte install sentinel,
back-compat with 10/8-byte). Makes wal_term_mark() truthful on this boot AND
every reboot (blob records are NOT checkpoint-filtered on recovery), so
decide_join returns Clean. Truthful, not a bypass: the artifact IS the leader's
authoritative state at (term, seq); a genuinely-divergent node (no install
sentinel) still surfaces tail_term > term -> Quarantine. Crash-idempotent via a
monotonic-by-term guard.
Fix 3: node-level reseed-restart coordinator — the single process-wide exit fires
once, only after every hosted shard requests a restart or a bounded grace
elapses, so one shard's self-restart never aborts a co-hosted sibling's
in-flight install (S>1). No-op on the S=1 production topology.
Fix 4: is_ready() returns 503 while any reseed marker (SnapshotRequired or
Quarantine) is latched, closing the plain-restart serve-while-behind gap;
readiness is bounded staleness, not "ready the instant the process is up".
Tests: decide_join loop/fix/bounded-reseed unit; install-sentinel 18-byte
round-trip + back-compat; engine durability (term marker survives a checkpoint
advanced past it + crash-reopen); reseed-restart gate (5 cases); reseed_install
carries the term. Verified: cluster_reseed 4/4 (zero-loss rolling restart x2,
quarantine reseed, failover oracle), reseed_install 3/3, m12_reseed_term_marker
4/4, cluster_membership mp_idle/mp_dns/mp_remove x2, tidal-server lib 154/154.
mp_scale_3_5_3 and mp_seed_join_snapshot_catchup OOM on this host (22GB colima
VM); their /health/startup failure is process-down, not the is_ready path Fix 4
touches.
Durable `leader_acked` frontier in `ShardReplica` tracks the highest seqno
acked under `ack=leader` (journal-only, un-replicated); `decide_join` now
quarantines on THIS node's own frontier rather than comparing stream numbers
across stream boundaries — eliminates false-quarantine churn on rolling
restarts. `SHUTDOWN_HANDOFF_WAIT` (3s) drains the leader's tail to quorum
before step-down so the next leader inherits a clean prefix. New
`load_leader_acked`/`persist_leader_acked` helpers; `cluster_reseed.rs` gains
the divergence-fix regression suite; `replication_ops.rs` threads the signal.
Soak-eval: `tidal_stress::soak_eval` + `soak-eval` binary implement the
30-night streak (ledger.tsv × restarts.tsv → streak.tsv); monitor and nightly
CronJob k8s YAMLs updated; phase-9 doc clarifies the dual-stream streak
definition (ledger PASS AND zero pod restarts in window). `run-reliability.sh`
gates the election-divergence suite before any k8s push.
Release tooling: `docker/release/` multi-stage Dockerfile + DR image;
`scripts/build-release.sh` single repeatable cross-compile+buildx path.
Read-SLA fix (rc12→rc13 — cpu-cgroup starvation → multi-second p99 + churning
elections):
- offload.rs: add SEARCH_GATE semaphore (core_count+1 permits, 50ms shed to 429)
so per-shard searches gate on CPU, not reactor threads; concurrent scatter_merge
fan-out (join_all) replaces the serial blocking offload_region_read loop
- node.rs: scatter_merge → async; per-shard futures run via offload_search
(each acquires one SEARCH_GATE permit, moves it into spawn_blocking so the
permit is held for the search's full CPU lifetime)
- main.rs: explicit tokio runtime with worker_threads floored at 4, independent
of the cgroup quota — keeps the control plane (heartbeat/election/apply) on its
own workers even when quota < 4
- k8s statefulset: CPU limit 2→3 (was: available_parallelism()=2 → only 2 async
workers; search burst starved the reactor)
- tidal/wal/compaction.rs: WAL_RETENTION_SEGMENTS 4→16 (64 MiB→256 MiB per-shard
catch-up window; a briefly-down follower across a rolling restart streams up
instead of forcing snapshot reseed; disk floor 768 MiB/pod, self-trimming)
- cluster_reseed.rs: OFFLINE_ITEMS 1800→5600 to exceed the new 16-segment
retention window (19 segs > 17); fix sequential quarantine/reseed race via
await_status_bool
tidalctl S3/R2 backup DR:
- tidalctl/Cargo.toml: aws-config, aws-sdk-s3, aws-credential-types, tokio, tempfile
- commands/s3.rs: S3Target + export_dir (upload every file, manifest last as
atomicity marker) + import_to_dir (download prefix into temp staging dir)
- commands/backup.rs: run_backup/run_restore accept Option<&S3Target>; S3 export
is additive after local fsync barrier; S3 import stages into TempDir then runs
the unchanged verified restore on it
- main.rs: --s3-endpoint / --s3-bucket / --s3-prefix flags; all-or-nothing
endpoint+bucket validation; usage updated
tidal-stress/k8s: recall-rc12-spread-job, soak-nightly-cronjob, soak-monitor,
soak-results-pvc, t5-readtput-job manifests
Fixes the rc9 over-correction: forcing baseline for ALL nodes (including
caught-up ones) caused needless reseed cascades. Now only divergent nodes
(frontier > baseline) use baseline as the reseed seqno; at/below-baseline
nodes use frontier+1 so the leader picks cheap catch-up vs snapshot.
Also skips the HNSW graph checkpoint on SIGTERM when the shard is reseed-
pending: the in-memory index reflects suspect/divergent data the next boot
discards, so saving it risks a "Failed to read vectors" failure on the
post-reseed open. Durable checkpoints and WAL flush still run.
close_shared() gains a save_graphs bool; shutdown_inner_impl() is the
shared implementation; node.rs passes !reseed_pending.
Root-caused and fixed five sharding bugs exposed on the real k3s 3-shard
cluster (rc5→rc7), plus a divergent-rejoin reseed loop found in rc9:
1. reseed shard-awareness (Bug 3, keystone): `run_boot_install_for_region`
visits each hosted group's own shard subdir; per-group leader discovery
appends `?shard=N` so a divergent shard heals from its own leader (not
shard-0's WAL/term — cross-shard contamination).
2. leader self-join term (Bug 4): `become_leader_for_term` now calls
`note_self_won_term` so the elected shard's `joined_term` is set and
`cluster_promote` routes rebalances correctly (was: topology-era mis-read
→ legacy fenced promote → 500).
3. boot self-heal self-pull guard (Bug 2): `leader_shard != my_shard` gate
prevents a node pulling its own stream (its stream isn't a registered peer)
→ eliminates the `PeerUnreachable(self)` loop.
4. scatter-merge degraded partial (Bug 1): failed shard logs + continues
instead of `?`-failing the whole read; bounded read-admission semaphore
(`offload.rs`) sheds as 429 instead of piling into a 36s p99.
5. WAL retention (Bug 5): `compact_wal_retained` keeps `WAL_RETENTION_SEGMENTS=4`
most-recent sealed segments; online path gets the same retention clamp.
Prevents brief-restart forced-reseed.
6. divergent-rejoin reseed loop (Bug 6, rc9): `note_quarantined` latches
`from_seqno = stream_baseline` (not `frontier + 1`) so `wal_covers`
returns `needed=true` and the snapshot installs instead of looping.
Also: `TidalDb::close_shared` for deterministic HNSW save on cluster SIGTERM
(HNSW graph was not saved when request-scoped Arc clones were alive at shutdown);
updated profiling doc with full rc8/rc9 fix narrative; k8s recall job YAMLs.
Boot now LOADS the per-slot HNSW graph instead of rebuilding it. Clean
shutdown writes {data_dir}/vector/<kind>__<slot>.usearch; the next open loads
it when it matches the durable corpus (seconds), falling back to a full rebuild
only when the graph is missing/stale/corrupt. Eliminates the multi-minute boot
rebuild (~50-70 min at 1M/1536-D) that let the WAL compact past a restarting
node and triggered the reseed cascade.
Graceful SIGTERM now actually runs the close: bounded_drain caps the post-signal
HTTP drain (TIDAL_SHUTDOWN_DRAIN_MS, default 15s) then runs the deterministic
close regardless — sibling keep-alive connections no longer block the drain past
the k8s 60s grace into a SIGKILL (which cannot run Drop). ClusterNode and
ShardReplica::shutdown are now &self (db handle is an ArcSwapOption) so the close
fires even when a stuck connection task holds an Arc.
Fix USearch insert to be a true upsert (remove+add): it was unconditional add,
which a multi:false index rejects on a reseeding follower's post-snapshot WAL
replay -> applied_events stalls -> catch-up deadlock -> unrecoverable cluster.
Also: circuit-breaker peer last-contact tracking; real k3s 1536-dim deploy +
recall findings (recall@10 0.9869, read p99 8.71ms @ 200rps @ 100k) in
docs/profiling/m12-cluster-deploy-findings.md; new tidal-stress k8s jobs and
m12p6 graph-persistence + SIGTERM tier-3 regression tests.
Completes the seed-join-over-TLS enablement begun in 8e39ee1. A real
kubectl scale 3->5 on a real mTLS k8s cluster (kind) exercised the seed-join
path over TLS for the first time and surfaced two more blockers beyond 8e39ee1's
https-seed / ready-only-Service / up-front-rustls-provider fixes — both of which
crash-looped every scale-up joiner with the same opaque 'could not join within
120s'. The plaintext in-process harness is blind to all of them.
- certs.yaml: a real TWO-TIER PKI. The leaf was issued DIRECTLY from a selfSigned
Issuer (a self-signed CA:FALSE end-entity whose ca.crt is a copy of the leaf);
the joiner's strict webpki verifier rejected the peer cert as UnknownIssuer.
Now: selfSigned Issuer -> CA cert (CA:TRUE) -> ca: Issuer signs the leaf.
(scripts/gen-cluster-certs.sh already did this; the two were inconsistent.)
- join_boot.rs: grpc_tls_for() fallback. own_grpc_tls/self_tls_spec looked up the
joiner's OWN region in the knob file to find its TLS material, but a seed-joiner
is NEVER in the shared-ConfigMap regions: list -> None -> the seed client built
with NO CA (the real UnknownIssuer cause) and a plaintext synthesized topology.
Fall back to ANY region's block (every pod mounts the same cert files).
- join_boot.rs: STATUS_POLL_TIMEOUT 500ms -> 5s (env TIDAL_SEED_STATUS_TIMEOUT_MS);
a cold TLS handshake under contention blew the sub-second budget. Discovery now
logs each poll failure at WARN with the full error source chain (a silent loop
made every bug present as the same 120s timeout).
- statefulset.yaml: pin the m12-8e39ee1 server image (carries these fixes).
- k8s/cluster-t4-kind + tidal-stress/k8s/t4-*: local-kind T4 overlay + seed/load.
Verified GREEN on kind: idle scale 3->5, both joiners seed-join over mTLS, catch
up, and flip /health Ready in 13s via the idle-readiness heartbeat convergence;
auto-promote to Voter; full content parity; all 5 regions lag=0. clippy clean;
mp_seed_join_snapshot_catchup + mp_idle_cluster_..._without_traffic green;
tidal-server/tidal-net lib green. A separate, root-caused snapshot-frontier bug
on a DEEPLY-compacted WAL (node.rs:734 last_wal_seq=0 for a state-only artifact)
is documented as a follow-up — left unfixed because a naive patch broke the
in-process snapshot test (own-WAL<->stream numbering); the GREEN run uses a small
corpus (stream catch-up) to keep that path out of scope. See
docs/profiling/m12p5-idle-readiness-elasticity.md §6.
The m12p5 idle-readiness work converged on an idle cluster, but the real
T4 1M/1536 scale-up over mTLS still failed to admit new pods. Three real
blockers, all invisible to the plaintext in-process tests:
- CryptoProvider crash-loop: the seed-join/reseed boot path builds a
blocking reqwest (rustls) HTTPS client on a dedicated boot thread BEFORE
GrpcTransport::new installs the process-wide provider, so every TLS joiner
panicked. Install it at the top of main(); ensure_crypto_provider() is now
pub, idempotent, harmless on the plaintext standalone path.
- Wrong seed scheme + target: peer_url honors an explicit URL scheme
verbatim, so http:// dialed plaintext at the TLS :9500 port. Seed is now
https:// AND points at the ready-only client Service (ClusterIP VIP), not
the headless peers Service — so a joiner never round-robins onto a
not-ready pod (incl. itself) and burns the 120s discovery window.
- Too-tight poll budget: a cold status poll pays a full rustls handshake on
top of DNS+TCP; under CPU contention that alone blew the 500ms budget, so
the joiner timed out every poll for the whole window despite the peer being
reachable. Status-poll timeout is now 5s (env: TIDAL_SEED_STATUS_TIMEOUT_MS)
with a separate 2s connect timeout (dead seeds still fail fast) and
debug-level logging on every discovery failure mode.
Refactors riding along:
- on_heartbeat takes a HeartbeatContext struct (additive fields, no silent
u64 transposition) across tidal-net, election_driver, and both test hooks.
- ShardReplica::applied_for_leader_shard centralizes per-source-shard keying
(BUG 1) shared by the readiness drive and local_status.
- idle-readiness test now asserts convergence within ½ budget — a slow-path
regression (periodic self-heal / status-poll dependency) the binary budget
check would otherwise wave through.
New k8s T4 manifests: cluster-t4-kind kustomization + single-group topology
patch; tidal-stress t4 seed/load Jobs.
Leader heartbeat now carries its live flushed WAL frontier (leader_last_seq,
proto field 14) so a snapshot-installed joiner converges its sticky readiness
latch from the heartbeat — which flows even on a fully idle cluster — instead of
only from observed ship traffic or an external status poll. Fixes the
idle-readiness stall (WORKLOG 2026-06-13: an 11.5h /health 503 hang where a
caught-up joiner never joined the Service VIP).
- proto: HeartbeatRequest.leader_last_seq (field 14); 0 = pre-m12p5 leader → fall
back to the status-poll readiness path
- ElectionHooks::on_heartbeat threads leader_last_seq through net + driver
- ShardReplica::note_leader_frontier_for_readiness folds the frontier into the
lag gauge (monotonic per shard) and drives the readiness latch using a REAL
leader frontier (never the uninitialized-0 gauge, which would false-converge a
still-behind joiner); a joiner that WINS leadership converges trivially
- tier-3 regression: mp_idle_cluster_snapshot_joiner_flips_ready_without_traffic
— snapshot joiner flips /health ready on an idle cluster with zero writes and
no status poll, then proves content parity (honest convergence)
- certs: wildcard pod SAN (*.tidaldb-peers...) in k8s/cluster/certs.yaml and
scripts/gen-cluster-certs.sh so StatefulSet scale-up/down with --seed needs no
cert re-issue (T4 scale-to-5 broke mTLS on tidaldb-3/4); explicit per-pod
names kept as belt-and-suspenders
- docs/profiling/m12p5-idle-readiness-elasticity.md: root-cause + fix writeup
Scale write throughput across data-shard groups while keeping a single unified
read surface:
- scatter_gather.rs: pooled fan-out across shard groups (replaces per-request
client construction); cross-shard query results merged on one node
- cluster/node.rs: cross-shard read routing — a read on any node gathers from
every shard group's leader and unions results
- cluster/forward.rs: fix h2 204 forward-relay bug (relay_forwarded skips body
for 1xx/204/304 — synthesized JSON body on a 204 triggered HTTP/2 RST_STREAM
on the real mTLS plane)
- dto.rs: cross-shard query/result DTOs
- k8s/cluster/: enable 3-group `shards:` topology (statefulset, service-peers,
topology-configmap)
- k8s/cluster-local-kind/: local-kind overlay to run the T5 gate without Ref-A
- tidal-stress/k8s/stress-job-t5.yaml: 2-generator sharded throughput job
- tests: cluster_cross_shard_reads.rs + multiproc support; ran real on kind
- docs/profiling/m12p4-t5-sharded-throughput.md: T5 throughput findings
apply_crdt_state force-sets accumulated scores outside apply_event_local,
so it bypassed the single note_write() chokepoint that keeps the trending
top-K cache fresh. A node going quiescent right after a partition heal kept
serving the pre-reconciliation candidate set indefinitely. Invalidate the
cache in apply_crdt_state too, with a regression test that reconciles a new
high-score entity and requires it in the next candidate read.
Also: extract the for_you/related ANN candidate cap to a named constant
(ANN_PROFILE_CANDIDATE_LIMIT), keep the recall test's ef_search in lockstep
with its construction default (honored since m12p3), and clarify the
vector_search region doc (always null until m12p4 cross-shard reads).
End the "replicated XOR sharded" split: S shard groups, each a
replication group at RF with its own elected leader, leaders balanced
across nodes; any gateway hash-routes.
- One unified write surface: /items,/embeddings,/signals hash-route to
the owning shard group's leader (ShardRouter FNV-1a) AND replicate at
RF. x-tidal-ack/x-tidal-seq, quorum await, NotLeader/QuorumTimeout are
per-group; NotLeader names the group.
- Rebalance verbs (L3): POST /cluster/shards/{id}/transfer (fenced
leadership move) + /cluster/shards/{id}/replicas (add/remove replica).
A ?shard= selector threads through every per-shard admin verb and is
propagated on intra-group forwards (ShardReplica::admin_path). S=1 is
byte-for-byte (no selector, no shard in NotLeader body).
- Tier-3 exit gate (cluster_sharding.rs): 3 nodes × 3 shards × RF=3 over
real OS processes — SIGKILL a node under ack=quorum load → only its
shard-leaderships re-elect, reads never stop, zero acked loss across
random kill points; plus a rebalance-verb test. Harness:
MultiProcCluster::start_sharded.
- tidal-stress drives the single path (WritePath::Leader|Sharded gone),
spreading writes round-robin across gateways or pinning --leader-url.
- Throughput: local 3×3 sustains 3,000 quorum signal-writes/s @ 0% err,
~30% CPU, lag ~0 (generator-bound). ≥5,000/s + ≥2.5× scaling is Ref-A.
Known follow-up (tracked): per-group-aware node readiness and cross-node
read fan-out under PARTIAL placement.
ClusterNode hosts a BTreeMap<ShardId, Arc<ShardReplica>>: writes hash-route
to the owning shard leader, reads scatter over shard groups. In-group
shard==region preserved so the engine and tidal-net are untouched; S=1 stays
byte-for-byte (today's cluster is a 1-shard × RF=N group). Topology grows
shard-group awareness; membership, election, forward, reseed, and join_boot
thread ShardId through.
Proven by an in-process 2×2 RF=2 gRPC test plus S=1 parity, incl. tier-3
real-OS-process failover. clippy/fmt clean.
Kind-3 term markers in the WAL stream, STREAM-relative vote frontiers,
heartbeat-only divergence detection + quarantine, and fenced promote.
Elections converge in 0.6–1.0s; zero acked-write loss across all kill points.
Closes G5 (leaderless recovery) from the v0.9 wave.
WAL segment format: 8-byte TSEG header (magic + version byte + 3 reserved)
prepended to every new segment. Legacy headerless segments (m0-m11p3) read
as implicit v0 — no migration. Unknown magic/version surfaces as
WalError::SegmentFormatUnknown at open time; foreign files are never
repaired or truncated (fixes the silent data-loss path from the p3 rollout
incident where torn-tail repair zeroed a follower's unreadable segments).
Catch-up transport: FAILED_PRECONDITION ("snapshot required") and stream
errors that skip the shard now arm a timer retry (re-arm-on-skip is the
load-bearing liveness fix — without it a skipped pull never re-fires and
the follower stays permanently behind). Single retry pending per shard;
CatchupRunner owns the Arc'd state shared between the retry tasks and the
transport. Test: tidal-net/tests/catchup_retry.rs covers the retry path.
Stress: k8s stress-job-t2a/t2b yaml + ops/stress-test-p3-t2 runbook.
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.
Two correctness bugs in multi-process cluster mode (m8p10), both found live on a
real 3-pod k3s cluster while validating the deployment, both invisible to the
existing in-process / unauthenticated test suites:
1. Forwarded item/embedding writes dropped on the floor. create_item /
write_embedding gated the leader's peer broadcast on `if internal { return }`.
A write to a NON-leader gateway is forwarded to the leader with the internal
marker set (loop-prevention), so it hit that branch and terminated WITHOUT
broadcasting — the item landed only on the leader. Signals were unaffected
(the WAL relay ships regardless of the marker), which masked it. Fix: gate on
leadership, not the marker — a follower applying a marked broadcast/heal
terminates; the leader (external OR forwarded) always fans out. Forwarded
writes now return the {replicated_to,failed} report instead of a bodyless null.
2. Heal item/embedding backfill 401'd whenever TIDAL_API_KEY is set.
post_marked_blocking sent the internal marker but no Authorization header. The
marker is a trust signal, not an auth bypass (the bearer middleware runs
first), so every backfill POST was rejected 401 — a region that missed an item
while down stayed permanently inconsistent at lag 0. Unauthenticated tests
never caught it. Fix: thread TIDAL_API_KEY into RegionClusterState and attach
it (same key on every region) to the backfill POSTs.
Verified live: forwarded writes via follower gateways converge to all 3 regions;
a region scaled to 0 during an item write backfills on heal (item_failures=0).
Follow-up: add multiproc regression tests with auth for both paths.
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.
Resolves every finding in docs/reviews/M0-M10-code-review-2026-06-08-pass2.md
across the engine, network, server, and CLI crates: session restore,
replication/CRDT, WAL format and recovery, storage indexes, query/ranking
executors, cohort/community governance, and scatter-gather routing.
Adds regression tests:
- review_pass2_creator_search_filter
- review_pass2_d_replication
- review_pass2_query_for_session
- review_pass2_storage_indexes_bitmap_cache
- review_pass2_zone_a_sessions
Verified: cargo clippy -D warnings and full test suite green across all crates.
- Eliminate the tidal/ self-contained doc mirror; docs now have two canonical
homes (root *.md and docs/), with planning/specs/research/reviews moved up
- Remove stale .agents/skills and .ai mirrors; canonicalize skills under .claude/
- Add pre-commit hook + scripts/check-docs.sh doc-guard + scripts/install-hooks.sh
- Implement M0-M10 seven-dimension review findings across engine, net, server,
and tidalctl (durability, replication, query, WAL, storage, CLI hardening)
Resolves the 142 findings from tidal/docs/reviews/CODE_REVIEW_m0-m10.md across
the engine, server, net, and CLI surfaces:
- WAL/session-journal durability, checkpoint format, and crash-recovery hardening
- Replication shipper/receiver, tenant isolation, and migration paths
- Cluster scatter-gather, router, standalone server + health/offload endpoints
- tidalctl refactored into command modules with JSON output and WAL-state tooling
- Cohort, governance, signal-ledger, and vector-registry correctness fixes
- Expanded UAT/integration/durability test coverage across all milestones
Three changes closing M8 gaps identified during verification:
1. ROADMAP.md: Mark m8p8 and m8p10 as PARTIAL (not COMPLETE).
Added Known Gaps table (G1: in-process transport, G2: tier-3
tests, G3: hash inconsistency).
2. SimulatedCluster transport now pluggable via ClusterConfig.transports.
Default (None) uses new ChannelTransport (crossbeam, same behavior).
When Some, accepts external transports (e.g., GrpcTransport from
tidal-net). Updated redeliver_missed to use &dyn Transport.
Zero regressions: all 1209 lib + 8 m8_uat tests pass unchanged.
3. Multi-process E2E test harness (tidal-server/tests/cluster_e2e.rs).
ClusterHarness spawns real tidal-server cluster OS processes,
allocates dynamic ports, generates topology YAML, polls health,
and cleans up via SIGTERM. Two tests: smoke (write + converge +
verify follower reads) and promote (leader change + continued writes).
Feature-gated behind cluster-e2e.
Add support for defining ranking profiles in schema YAML, allowing
deployments to override builtin profiles with deployment-specific
signal names and tuning parameters.
- Add override_register() to ProfileRegistry for clean builtin replacement
- Add with_profiles() to TidalDbBuilder to thread schema profiles
- Parse profiles section in config.rs with full sort/strategy/agg support
- Validate that profile signal references exist in schema at startup
- Change load_schema() to return (Schema, Vec<RankingProfile>)
This closes the gap where the builtin for_you profile referenced
signals (view, like, share) that don't exist in deployment schemas,
causing all feed scores to normalize to 1.0.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Clap now reads PORT from the environment, accepting either a bare port
number (e.g. 8080 -> 0.0.0.0:8080) or a full host:port. CLI --listen
flag still takes precedence. Deploy Dockerfile defaults PORT=9500 and
removes the hardcoded --listen argument.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Matches the response shape used by all other services in the
infrastructure (ok, service, cause on failure).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add /health/startup and /health/live probes, flip readiness to 503 on
SIGTERM so k8s stops routing before drain. Update standalone Dockerfile
for internal deployment: port 9500, schema mounted at runtime (not baked
in), persistent data dir, non-root user with fixed UID 10001.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Extract redeliver_missed(tx, db, log) helper into cluster_transport.rs
- heal_region now removes partition then immediately ships any missed
batch-log entries to the healed follower's channel
- await_convergence refactored to call the same helper (no logic change)
- tidal-server: reload_text_index before search in cluster mode
- tidal-server: write_signal returns Result instead of panicking on unknown signal
- tidal-server: leader shows lag_events=0 (writes directly, no receiver thread)
- tidal-server: fix cluster mode error propagation (ServerError::from)
- docs/runbooks/cluster.md: add full cluster operations runbook
- docker/: add Dockerfile for containerised cluster deployment
- README.md: add tidal-server HTTP API getting-started section
- Split oversized source files per CODING_GUIDELINES §9
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Fix 9 compilation errors across tidal-server and testing/cluster.rs so
that `cargo run -p tidal-server -- standalone` works end-to-end.
Bugs fixed:
- cluster.rs: wrong return types `RetrieveResult`→`Results` and
`SearchResult`→`SearchResults` on retrieve/search helpers
- state.rs: `RegionId` imported from private path; now uses
`tidaldb::replication::RegionId`
- state.rs: missing `Ok()` wrapper on `ServerState::cluster()` return
- state.rs: cluster match arms returned `TidalError` where `ServerError`
required; added `.map_err(ServerError::from)` on write_item,
write_embedding, retrieve, search
- error.rs: `Result<T>` alias lacked default E param; callers in router
used two-arg form `Result<T, AppError>` — changed to
`Result<T, E = ServerError>`
- router.rs: `with_state()` called before cluster routes were added,
making `app` `Router<()>`; restructured to call `with_state` once at end
- router.rs: `TidalErrorWrapper(TidalError)` used to map `QueryError`;
fixed with `|e| TidalErrorWrapper(e.into())`
- router.rs: `Search::limit()` takes `u32` but code cast to `usize`
- router.rs: `bm25_score`/`semantic_score` are `f32` in SearchResultItem
but `f64` in response struct; added `.map(f64::from)` conversion
Also split cluster.rs into cluster.rs + cluster_transport.rs to stay
under the 600-line limit required by CODING_GUIDELINES §9.
Verified all README curl examples work:
POST /items, POST /embeddings, POST /signals, GET /feed, GET /search,
GET /health all return correct HTTP status codes and JSON responses.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
