---
title: "Readiness Check"
method: GET
path: "/health/ready"
---

# Readiness Check

`GET /health/ready`

Readiness probe for Kubernetes (`readinessProbe`). NOT the liveness probe.

`/health` above stays the LIVENESS probe: static, no I/O, so a merely busy
event loop never gets the pod killed. This endpoint answers the different
question k8s asks for readiness - "should this pod receive traffic?" - and
it can answer no. Before it existed, a pod with a dead database or an
unapplied migration passed readiness, joined the Service endpoints, took
live class traffic, and made `kubectl rollout status` report success.

Checks (see app/health/readiness.py for the full rationale):
  - database: a real `SELECT 1` over its own short-lived connection, hard-
    bounded by libpq `connect_timeout` + `statement_timeout` (~2s), and
    deliberately NOT taken from the main pool so a load spike cannot fail
    readiness on every pod at once.
  - migrations: the DB's alembic revision vs the migration head shipped in
    this image. DB BEHIND code fails (the code will read columns that do
    not exist). DB AHEAD of code does NOT fail - during an expand/migrate
    deploy, and during a rollback, the old pods are intentionally running
    against a newer schema, and failing them would cause the outage the
    zero-downtime rollout is meant to avoid.

Contract: 200 when servable, 503 when not. k8s only reads the status code;
the JSON body names the failing check for humans. Never raises - an
unexpected exception is turned into a 503 with a reason, because a 500
stack trace from the probe looks like an app bug and hides the cause.

Plain `def` on purpose: the DB layer here is synchronous SQLAlchemy +
psycopg2, so Starlette runs this in the threadpool. Do not make it
`async def` without an async driver - blocking the single uvicorn worker's
event loop under a full class of students is worse than having no probe.

## Response `200`

Successful Response

- unknown

---

[API](https://skmtc.dev/fluentea/apis/aurqa-language-learning-platform-refactored.md) · [All operations](https://skmtc.dev/fluentea/apis/aurqa-language-learning-platform-refactored/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/fluentea/aurqa-language-learning-platform-refactored/revisions/45cbba31aa7d/schema)