RDSNonCPUUtilization #

Meaning #

Alert is triggered when an RDS instance has more active queries than available vCPU.

Impact #

Performances are degraded because some queries could not be executed.

Diagnosis #

Tips

This situation usually occured when SQL queries are blocked by software reason (e.g. Locks) or hardware saturation (e.g. IOPS)

Identify the waits type of active queries on RDS Performance insights.

Select Top waits and Top database to quickly identify wait reason and database.

Mitigation #

1. If Lock:relation, identify and fix the lock reason

   For other wait type, looks at https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Tuning.html

2. Kill the SQL queries

Additional resources #

• https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Tuning.html
• https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_PerfInsights.Overview.ActiveSessions.html