Database pool saturation¶

Alert: HubuumDatabasePoolSaturated.

Meaning¶

A process has used more than 90% of its configured pool for ten minutes.

Diagnose¶

Identify the instance and runtime role. Check acquisition failures, query latency, PostgreSQL locks and connection capacity. Inspect slow work before increasing pool size; aggregate database connection limits across replicas.

Recover¶

Reduce or pause the identified workload, resolve blocking queries, or restore database capacity. Avoid raising all replica pools together without a database capacity calculation.

Inspect and confirm¶

Evaluate the alert expression in Prometheus, selecting the affected deployment:

max by (deployment, instance) (hubuum_db_pool_connections{state="checked_out"}) / max by (deployment, instance) (hubuum_db_pool_connections{state="configured"}) > 0.9

Inspect non-secret settings with an administrator token:

curl --fail --silent -H "Authorization: Bearer $HUBUUM_TOKEN" \
  "$HUBUUM_API/api/v1/admin/config" | jq .

Check the affected process logs for the same time window. For a single host:

cd /opt/hubuum
sudo docker compose logs --since 15m hubuum-api hubuum-api-standby

Use sudo podman compose for Podman, or the equivalent workload logs in a distributed installation. Keep credentials and raw resource details in controlled logs, not metric labels or alert titles.

Escalate to the deployment owner when the symptom persists after the documented recovery, affects every replica, or indicates an integrity problem. Confirm the underlying operation succeeds and observe a full alert window with current scrapes. A vanished series alone does not prove recovery.

Tune thresholds and for durations in the shared rule file to the deployment's workload. Review service objectives and aggregation and the metrics guide before changing queries.