Cloud SQL PostgreSQL and PGAdmin connections maxing

[tangedahl]

Hello!  I'm having an issue where when I am doing a lot of queries in PGAdmin against my Cloud SQL Postgres instance and i'm hitting my 25 connection max.  How can I have these active connections clean up or expire to avoid maxing out the active connection limit?  I'd rather do this than just increasing the allowable connections.

Thanks,
Eric

[ms4446]

To manage and clean up connections in your Cloud SQL Postgres instance without increasing the allowable connection limit, consider the following strategies:

Idle Connection Timeout:

You can configure idle_in_transaction_session_timeout and statement_timeout in your PostgreSQL settings to automatically terminate idle sessions and long-running queries. For example, setting idle_in_transaction_session_timeout to '5 minutes' and statement_timeout to '10 minutes' will end any session idle for more than 5 minutes or any query running longer than 10 minutes. This helps prevent unnecessary connections from lingering and consuming resources.

Connection Pooling:

Implementing a connection pooler like PgBouncer can significantly improve connection management by reusing connections and limiting the number of active database connections. Configuring PgBouncer in transaction or session mode optimizes connection usage. Additionally, employing connection pooling within your application code can further reduce the overall number of database connections, enhancing efficiency.

Manual Termination of Idle Connections:

You can manually monitor and terminate idle connections using the following SQL command:

SELECT pg_terminate_backend(pid)  
FROM pg_stat_activity  
WHERE state = 'idle' AND state_change < current_timestamp - interval '5 minutes';

Optimizing Application Connection Handling:
Ensure that your application and PGAdmin close connections when they are no longer needed. Proper connection management within your application, possibly through connection pooling, can help minimize the number of open connections, reducing the risk of maxing out the connection limit.

Query Optimization:
Regularly review and optimize your queries to ensure they are efficient and do not hold onto connections longer than necessary. Inefficient queries can unnecessarily consume resources, contributing to connection exhaustion.

Additional Considerations:
While adjusting max_locks_per_transaction might be beneficial in specific scenarios involving numerous table locks, it is not a primary solution for general connection management. Always test any configuration changes or new tools in a non-production environment before applying them to your production database.