Multiple pipelines and application servers each maintaining their own connection pools. `max_connections` set too low for the workload. Connection leak — connections not closed after use. Lack of a connection pooler (PgBouncer, RDS Proxy) in front of PostgreSQL

Step 1: Check current connections: `SELECT count(*), state FROM pg_stat_activity GROUP BY state;`. Step 2: Deploy PgBouncer or RDS Proxy as a connection pooler in front of PostgreSQL.. Step 3: Increase `max_connections` in `postgresql.conf` (requires restart) — also increase `shared_buffers`.. Step 4: Audit application connection pools — ensure idle connections are returned to the pool.. Step 5: Kill idle connections: `SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE state='idle' AND state_change < now() - interval '10 min';`

High severitycapacity

Power BI Refresh Error:
53300

Q: How do I prevent 53300 errors in automated pipelines?

Add retry logic with exponential backoff, validate data quality before loading, and monitor pipeline failures in MetricSign to catch this error early.

What does this error mean?

The maximum number of concurrent connections (`max_connections`) has been reached. New connections are rejected.

Common causes

1Multiple pipelines and application servers each maintaining their own connection pools
2`max_connections` set too low for the workload
3Connection leak — connections not closed after use
4Lack of a connection pooler (PgBouncer, RDS Proxy) in front of PostgreSQL

How to fix it

1Step 1: Check current connections: `SELECT count(*), state FROM pg_stat_activity GROUP BY state;`
2Step 2: Deploy PgBouncer or RDS Proxy as a connection pooler in front of PostgreSQL.
3Step 3: Increase `max_connections` in `postgresql.conf` (requires restart) — also increase `shared_buffers`.
4Step 4: Audit application connection pools — ensure idle connections are returned to the pool.
5Step 5: Kill idle connections: `SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE state='idle' AND state_change < now() - interval '10 min';`

Frequently asked questions

How do I prevent 53300 errors in automated pipelines?