# Connection pool exhausted: first 30 minutes checklist

Source: https://releasefailures.com/incidents/connection-pool-exhausted/
Content version: 1.0.0
Verified on: 2026-10-21
Licence: CC BY 4.0

Definition: A new code path leaks or holds connections and the pool runs out under load.
- [ ] FM-01 Read the connection pool and connection pooler saturation for the primary database and count connections that stay open.
- [ ] FM-02 Match the start of the saturation to the latest deploy, a newly enabled feature flag or a newly scheduled background job.
- [ ] FM-03 Disable the feature flag that controls the new code path or background job, even when the link to the flag is not yet proven.
- [ ] FM-04 Halt the new background job directly if no feature flag controls it.
- [ ] FM-05 If no flag or job explains the saturation, revert the deploy that introduced the code holding connections.
- [ ] FM-06 Free stale database connections by hand while the revert rolls out, and confirm the open connection count falls.
- [ ] FM-07 Check for connections that open and never close before spending time on network diagnosis.
- [ ] FM-08 Post a status update that names the failing operations, such as logins, pushes or write requests, and the time the impact began.