Commit Graph

4 Commits

Author SHA1 Message Date
Ulysse Pence 16f490e345
fix(deriver): increase deriver polling backoff (#1015)
* fix(deriver): increase deriver polling backoff

* removes comment

* Removes config changes
2026-08-14 16:38:20 -04:00
Rajat Ahuja bf494257b8
add read db (#773)
* feat: implement read DB and fix queue stale cleanup

* fix: use read_db in internal methods

* fix: mention read db in the CLAUDE.md

* fix: make TRACING checkout hook autocommit-safe; sample cleanup-gate jitter once

The DB.TRACING checkout hook ran `SELECT set_config(...)` at pool checkout,
before the dialect applies the read engine's AUTOCOMMIT isolation level. That
statement autobegins a transaction, and psycopg then refuses to switch the
connection into AUTOCOMMIT ("can't change 'autocommit' now: connection in
transaction status INTRANS"), so every read_only session 500s under TRACING and
the INTRANS connection leaks back to poison later write checkouts. Run the hook
in autocommit and restore the prior mode so it never leaves an open transaction;
set_config(..., is_local=false) is session-scoped and survives the boundary.
Add a regression test (fails without the fix) covering read_only + TRACING.

Also sample the stale-cleanup gate's jittered interval once per attempt instead
of re-rolling it every poll, so the spacing is a fixed deadline per cycle rather
than a random walk (and is testable at non-zero jitter ratios).

* fix: reset request_context in TRACING checkout-hook test

---------

Co-authored-by: Vineeth Voruganti <13438633+VVoruganti@users.noreply.github.com>
2026-06-10 13:28:36 -04:00
Vineeth Voruganti 9f26fdd2ea
Deriver Jitter (#765)
* fix(deriver): Remove connection retry logic and add jitter to polling interval

* chore(docs): Update changelog and document new configurations

* chore: increment version numbers
2026-06-02 11:48:36 -04:00
Vineeth Voruganti 396976db34
Connection Exponential Backoff (#758)
* feat(db): add connection retry, adaptive deriver polling, and pool metrics

Add resilience and visibility for DB connection handling under transaction-
pooler (Supavisor) saturation, where client-connection limits get exhausted
across many tenants.

- get_db/tracked_db now force an eager pool checkout with bounded exponential
  backoff (tenacity), retrying SQLAlchemy TimeoutError + OperationalError so
  transient pooler rejections degrade gracefully instead of 500ing. Toggle via
  DB_CONNECTION_RETRY_ENABLED (+ delay/backoff knobs); ~10s default budget.
- Deriver polling backs off when idle or erroring (base -> max, x2 each cycle)
  and snaps back to base on claimed work, cutting steady-state query load.
  Toggle via DERIVER_POLLING_BACKOFF_ENABLED (+ max/multiplier).
- Add scrape-time db_pool_connections Prometheus gauge (checked_out/checked_in/
  size/overflow, labeled api|deriver), registered in both the API lifespan and
  the deriver metrics server.
- Make SqlalchemyIntegration explicit in both Sentry inits; wrap connection
  acquisition in a db.pool.acquire span and capture live pool stats on
  retry-exhaustion.

* feat(db): add acquisition counter and in-flight query gauge

Build on the pool-connection metrics with two signals that turn detection
into diagnosis under transaction-pooler saturation:

- db_connection_acquisitions{outcome=ok|retried|exhausted}: counts how often
  connection checkout retries through pooler rejection — the alertable early
  warning before requests start failing.
- db_queries_in_flight: statements actually executing on the wire (via
  SQLAlchemy cursor-execute events, drift-proof across query errors). Pairs
  with checked_out: the gap reveals connections held but parked (the "idle in
  transaction during an external call" antipattern). Labeled namespace +
  instance_type only; gated on METRICS.ENABLED for zero overhead when off.

Add DB-free unit tests for retry outcomes, polling backoff, and in-flight
gauge drift handling.

* fix: address CodeRabbit review on PR #758

- db: roll back the session on a retryable checkout failure before
  retrying — a failed autobegin can leave it pending-rollback, making the
  next db.connection() raise instead of re-checking-out cleanly. Cheap
  Python-side cleanup when no connection was bound.
- metrics: guard DBPoolCollector.collect() so a pool-read/import hiccup
  can't raise and abort the whole /metrics scrape (Prometheus drops ALL
  metrics if any collector raises) — log and fall back to empty.

* fix(db): lazy retrying session + review fixes for connection backoff

Address Codex/CodeRabbit review on PR #758.

- Replace eager checkout with HonchoAsyncSession: a lazy AsyncSession that
  checks out its connection (with retry) on the first DB-touching call, not at
  construction. Request handlers doing non-DB work (embedding/file/LLM) before
  their first query no longer pin a connection across it, while the API path
  still gets checkout retry. Only the checkout is retried — the statement runs
  once via super(), so writes are never duplicated. Tracing's set_config moves
  into the same lazy acquire hook.
- Roll the session back on a retryable checkout failure before retrying, so a
  failed autobegin can't leave it pending-rollback.
- Lower default POOL_TIMEOUT to 5s and validate it stays under the retry budget
  for pooled (non-null) POOL_CLASS; update config.toml.example and v2/v3 docs.
- Clamp pool overflow gauge to >= 0 (was negative before the pool fills).
- Remove double-sleep in the deriver idle poll (true backoff cap, not 2x);
  make in-flight instrumentation registration idempotent.
- Tests: HonchoAsyncSession lazy/idempotent acquire, statement-runs-once,
  tracing, commit/rollback flag reset, get_db no-acquire-at-entry, polling-loop
  single-sleep, and the POOL_TIMEOUT/retry-budget validator.

* fix(db): cover all DB-touching session methods; clear flag on close/reset

Address Codex follow-up review on PR #758 (polish, no behavior-critical bug).

- HonchoAsyncSession: wrap get/get_one/stream/stream_scalars/delete in addition
  to execute/scalar/scalars/flush/merge/refresh/commit, so the "lazy checkout
  with retry on first DB use" guarantee has no holes. connection() stays
  unwrapped (acquire_connection_with_retry calls it — wrapping would recurse).
- Reset the acquired flag on close()/reset() too, so a session reused after
  close/reset re-acquires (and re-wraps retry) on its next DB use.
- Fix stale comments: connection retry now applies lazily to the request path
  via HonchoAsyncSession (config.py), and the FakeSession helper note.
- Tests: close/reset flag reset, and get/delete route through acquisition.
2026-06-01 12:57:07 -04:00