Commit Graph

16 Commits

Author SHA1 Message Date
jordan
c97aaa8e5b fleet remediation: make the workspace gate runnable, then fix what it caught
`cargo test --workspace` could not run at all: dependency resolution failed with
"aws-types@1.3.16 requires rustc 1.91.1" on the 1.91.0 default toolchain, so the
gate the project documents was dead. Making it run exposed a compile break and
two wrong tests that had been invisible for months. Now green end to end:
143 suites, 3155 tests, exit 0.

Toolchain
- rust-toolchain.toml pins the DEV toolchain to 1.91.1. The published MSRV stays
  `rust-version = "1.91"` (the engine builds on 1.91.0); only tidalctl's AWS SDK
  chain needs the patch release, and it now declares that itself.

Consumer crates migrated to the current engine API (clean cutover)
- iknowyou-engine: `AgentPolicy` gained five m10 read/profile-override fields;
  the literal now spreads `..AgentPolicy::default()` as the engine's own doc
  example does, so future fields do not break it again.
- forage-engine: `RetrieveResult` gained p1 `reasons`. The app builds its own
  candidate pool, so it now tags what it knows: PreferenceMatch for the
  preference-vector blend, SemanticMatch (with the seed item) for
  similar-to-saved, ExplorationBudget for pinned discoveries.
- forage-engine: `url_to_item_id` folded into the u32 item universe. The engine
  narrows item IDs to a u32 slot in durable per-user state and rejects anything
  above u32::MAX rather than alias two items forever, so every add_item with a
  64-bit FNV hash failed. 9 of 28 smoke tests were failing on this alone.
- forage-engine: bridge items read the top-2 preference CLUSTERS via
  `query_vectors`, not the single centroid from `preference_vectors().get()`.
  Since m12 that accessor returns only the strongest cluster, so a tech+jazz user
  whose interests split into two clusters looked single-interest and never
  bridged. Falls back to top-2 dimensions when a user has one cluster.

Reconcile tests corrected to the shipped contract
- tidal/tests/m8p3_reconcile_production.rs asserted `3 + 5 == 8` for a windowed
  count after heal. `take_crdt_snapshot` deliberately keys signal contributions
  to ONE canonical contributor (ShardId::SINGLE) because signals are relayed from
  a single writer, so per-node attribution double-counted every replicated event
  on every reconcile. Merge is therefore LWW on (last_update_ns, score) plus
  PN-counter per-node max: nodes converge on the more complete accumulator. The
  old expectation was asserting the bug that fix removed.
- Rewrote to assert convergence, count survival (not 0), and no inflation, and
  added `repeated_reconcile_of_converged_nodes_does_not_creep` - the regression
  guard for the creep itself, which nothing covered.

Pre-commit hook unified
- hooks/pre-commit dropped `-D warnings`: each crate's `[lints]` table is the
  source of truth (`clippy::all`/`unwrap_used` deny, `pedantic` warn), and the
  flag promoted ~58 deliberate pedantic warnings in integration tests to errors,
  making every Rust commit impossible.
- It now lints all five tidal crates instead of path-matching `tidal/`, which
  silently skipped tidal-server, tidal-net, tidal-stress, tidalctl and
  applications/ - the rot above lived in exactly those crates. Ported the
  CODING_GUIDELINES file-length, println, and unsafe-SAFETY checks from the
  divergent untracked copy that this replaces.
- CONTRIBUTING.md now documents the real commands and the toolchain/MSRV split.

Fleet recovery and soak
- scripts/restore-fleet.sh: the fail-closed selective restore, promoted out of an
  ignored tmp/ directory into the repository. Preflights retained storage,
  digest-pinned images, parked state, and aggregate plus per-PV-node scheduler
  headroom before the first scale; writes a durable transcript under
  tmp/restore-logs/ with structured start/error/rollback/complete events.
- k8s manifests park the standalone store, the RF3 cluster, and the soak monitor
  at zero replicas with restore-fleet.sh as the only supported scale-up path.
- soak-eval/soak-watch and the nightly CronJob fail closed on stale or missing
  restart evidence instead of silently skipping the restart-aware half of the gate.
- docs/ops/capacity-planning.md corrects the RAM envelope to the real hot-tier
  formula and separates analytic totals from the measured process envelope.
2026-08-16 12:38:14 -06:00
jx12n
1b5bcbacd7 fix(net): classify ship deadline as timeout, not partition (write-burst false-partition)
A client-side ship DEADLINE means the RPC did not round-trip within
request_timeout — which a slow-but-ALIVE follower produces under a sustained
1536-D ack=quorum apply burst (transport runtime momentarily starved by the
CPU-heavy HNSW apply on its single segment-receiver thread) exactly as a
genuinely blackholed peer does. Counting that as record_failure was the
write-burst false-partition: 5 such opened both followers' breakers, the commit
index stalled, ack=quorum 503'd, and retries re-burst the same starved peers
with no self-heal.

- CircuitBreaker::record_timeout: opens ONLY when the peer shows no recent proof
  of life (no round-tripped success/backpressure within reset_duration); neutral
  no-op when liveness is fresh; re-opens (never wedges) HalfOpen; never refreshes
  the liveness stamp (no reply arrived).
- PeerPool::send_to routes tonic DeadlineExceeded/Cancelled -> record_timeout;
  genuine severance still surfaces as connect-level Unavailable/transport reset
  -> record_failure and still opens the breaker.
- ship_timeout_breaker.rs: end-to-end proof over a REAL tonic WalShipping server
  (handler succeeds once then hangs past the client deadline) + 6 unit tests.

Also: re-scope G-S Scalability guarantee to read-throughput with the Ref-A
tidal-t5-readtput owner-test (write 2.5x is structurally impossible on 3-node
full-placement RF3); bump k8s image to m12-rc6 (live, commit 0919b0a); rustfmt
soak_eval / soak-eval / s3 / tidalctl.
2026-06-19 16:25:50 -06:00
jx12n
7cb9724911 chore(soak): re-scope nightly soak 500->200 rps (measured sustainable) + fix image drift
500 rps failed the capacity gate every night (peach mix is write-heavy; the
write path is structurally capped on 3-node RF3 full placement). A settled-
cluster capacity sweep measured the mix clean (0.00% error, 0 follower
restarts) at 100/150/200/250 rps; set the nightly target to 200 rps with margin
for a 1h x 30-night endurance run. SLO gates unchanged.

Also fix the image drift: the manifest pinned stress:m12-soak-eval (never
pushed -> ImagePull NotFound), while the live cronjob already ran the pullable
stress:m12-rc7-seedretry. The manifest now matches the live, pullable image.
2026-06-19 02:23:16 -06:00
jx12n
580142df49 feat(m12): election-divergence-fix + soak-eval streak + release tooling
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.
2026-06-18 13:08:53 -06:00
jx12n
a946c6128c fix(m12-rc13): read-SLA collapse + WAL_RETENTION_SEGMENTS 16 + tidalctl S3 DR
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
2026-06-17 15:47:37 -06:00
jx12n
727fbfcb6b fix(m12p6): 6-bug k3s 3-shard cluster repair (rc8+rc9)
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.
2026-06-16 22:34:21 -06:00
jx12n
a0399550d6 feat(m12p6): persist HNSW graph + bounded SIGTERM drain — boot loads, no rebuild
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.
2026-06-15 13:09:20 -06:00
jx12n
4db3f1e597 fix(m12p6): complete T4 TLS scale-up — two-tier PKI + join_boot grpc_tls fallback
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.
2026-06-14 22:41:59 -06:00
jx12n
8e39ee1078 fix(m12p6): T4 TLS scale-up enablement — https seed-join via ready-only Service + up-front rustls provider
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.
2026-06-14 20:29:37 -06:00
jx12n
31ee612f27 feat(m12p4): sharded ingestion — scatter-gather pool + cross-shard unified reads (L4)
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
2026-06-14 15:17:35 -06:00
jx12n
81093a6779 bench(1536): production-shape capacity — read path is cheap, quorum write is the ceiling
Switched content_vector to 1536-dim (text-embedding-3-small, thepeach production
width) and ran the realistic peach mix (feed-profile reads + signal writes) on the
m11p6 mTLS cluster.

Result: 1536-dim costs ~nothing on throughput vs 128-dim — knee still ~2,976 rps
(128-dim was 2,981). The write bottleneck is quorum-commit on the 2-worker leader
pool, not vector size. The vector READ path (feed-profile retrieve — the
db.retrieve(profile) path thepeach E2/R8 calls) stays p99 3-11ms through 1500 rps,
never the bottleneck. Memory is the only dim-sensitive resource (567-751 MiB/pod
at 20k items, ~12x 128-dim) — capacity-plan RAM, not throughput.

Recommended sustained target: <=1,000 signal-ingest rps (~1,200 full mix) — 40% of
knee, 2.5x headroom, survives single-node failover, write p99 ~45ms within SLA.

Also: fixed the stale "deployed schema is 128" note in tidal-stress (now reflects
the configurable width). Full writeup: docs/ops/benchmark-1536-peach.md.
2026-06-13 21:40:58 -06:00
jx12n
df0e1b98de feat(deploy+stress): m11p6/mTLS deploy fixes — HTTPS probes + TLS-aware generator
Deploying the m11-44b768b image (p6 sharding + p7 mTLS + p8 ops + p9 correctness)
surfaced two blockers; both fixed here.

1. statefulset.yaml: the m11p7 change made the :9500 HTTP plane serve TLS, but the
   startup/liveness/readiness probes still used scheme HTTP — kubelet got a TLS
   handshake back ("malformed HTTP response \x15\x03\x03") and pods never went
   Ready. Set scheme: HTTPS on all three probes (kubelet skips cert verification
   for httpGet probes, so the cert's DNS-only SANs are fine). Image pinned to the
   m11-44b768b amd64 digest.

2. tidal-stress: the generator's reqwest client did default cert verification and
   had no way to trust the cluster's private CA, so https:// targets failed. Added
   --ca-cert <pem> (verified TLS against the mounted tidaldb-cluster-tls ca.crt)
   and --insecure (skip verification, escape hatch). New StressError::CaCert for
   the PEM read fault.

stress-job-m11p6-baseline.yaml: T2-A-equivalent quorum-write throughput run on the
new stack — https:// targets, ca.crt mounted from the tidaldb-cluster-tls Secret,
--ca-cert verified TLS. Drops the removed --write-path flag (m11p6 unified the
write path to hash-routing).
2026-06-13 18:39:30 -06:00
jx12n
25ec7630a1 feat(k8s): m11p5 cluster manifest — local-path PVCs, initContainer, T3 tooling
statefulset.yaml:
- Pin image to m11p5 digest (173e803...)
- Add initContainer init-datadir (busybox, uid 10001) to create /data/db before main
- Set storageClassName: local-path (5Gi) — Longhorn networked-fsync caused 74-85% error rate

T3 tooling:
- tidal-stress/k8s/stress-job-t3.yaml: 1500 rps quorum-write job for election gate
- tidal-stress/scripts/t3-kill-loop-v3.sh: HTTP-polling kill loop (port-forward + curl,
  200ms poll, ns-precision timing, no exec into tidaldb pods)

T3 result: 10/10 kills PASS, max 6157ms (gate < 10 000ms), zero acked loss.
2026-06-12 22:01:37 -06:00
jx12n
bf57be18e1 feat(m11): membership, snapshot install, and reseed (m11p5) 2026-06-12 19:55:54 -06:00
jx12n
d0a52e4530 feat(m11): catch-up timer retry + TSEG segment version header (m11p4)
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.
2026-06-11 17:05:20 -06:00
jx12n
f640764d89 feat(tidal-stress): open-loop capacity load generator (thepeach feed workload)
New workspace crate: an open-loop, coordinated-omission-corrected HTTP load
generator + capacity ramp for the standalone and multi-process cluster surfaces,
modeling a thepeach feed session (feed reads + view/like/skip signals + search,
signal-dominated per their user-graph spec). Throttleable target rate, ramp
presets (smoke/quick/peach-100k/max) or rps:secs specs, peach/reads/writes/custom
mixes, leader vs sharded write paths, per-op p50/p90/p99/p999/max latency, a
backpressure-aware status breakdown (429/408/503/4xx/5xx/transport), and a verdict
translated to supported DAU. Runs in-cluster as a k8s Job (tidal-stress/k8s/).

Open-loop scheduler (scheduler.rs) fires at a fixed arrival rate and measures
latency from each request's intended send time, so a server stall inflates the
percentiles a closed-loop test hides; it shed-and-counts rather than blocking when
the in-flight cap is reached. Pure-Rust (tokio + reqwest/rustls), no engine deps.

Findings on the live 3-region k3s cluster (docs/ops/stress-test-thepeach.md):
reads scale to thousands/s at <15ms p99; the replicated /signals path saturates at
~90 signals/s (single-leader funnel + 2-worker write pool + synchronous gRPC ship);
the sharded path sustains 3,669 signals/s at 0 errors and ~27% cluster CPU (≈ the
100k-DAU peak, knee not reached). Overload degrades gracefully (429; 0 pod
restarts). thepeach's planned in-process embedding sidesteps all of it (write ≈82ns).
2026-06-10 21:54:21 -06:00