Fix Connection Pool in Postgres: Too Many Connections Solution (2026)
How to Fix “Connection Pool” in Postgres (2026 Guide) The Short Answer To fix the “Connection Pool” issue in Postgres, which is caused by too many connections, you can immediately reduce the connection pool size by running the command ALTER SYSTEM SET max_connections = 100; and then restarting the server. This will temporarily alleviate the issue, but for a more permanent solution, follow the step-by-step guides below. Why This Error Happens Reason 1: The most common cause of the “Connection Pool” issue is when the application or database configuration exceeds the maximum allowed connections, which is typically set to 100 by default. This can happen when multiple users or applications are accessing the database simultaneously, leading to an exhaustion of the connection pool. Reason 2: An edge case that can cause this issue is when there are idle connections that are not being closed properly, leading to a buildup of unused connections that still occupy slots in the pool. This can happen due to poor application design or misconfiguration of the connection pooling mechanism. Impact: The result of too many connections is that the connection pool becomes exhausted, leading to errors and preventing new connections from being established. This can have significant performance implications and even cause the database to become unresponsive. Step-by-Step Solutions Method 1: The Quick Fix Go to Settings > postgresql.conf Toggle max_connections to a lower value, such as 50, to reduce the connection pool size. Refresh the database configuration by running SELECT pg_reload_conf(); to apply the changes. Method 2: The Command Line/Advanced Fix To increase the connection pool size, you can use the following command: ...