SuperBizAgent-java/knowledge_base/rag-eval/database/mysql-connection-pool.md

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MySQL Connection Pool Runbook	MySQL connection pool pool exhausted max_connections HikariCP	Diagnose exhausted MySQL connection pools and distinguish application leaks from database limits.	database	mysql-connection-pool	Database > MySQL > Connection Pool	rag-eval	mysql connection pool database capacity	Use when MySQL clients report exhausted pools, connection acquisition timeout, max_connections pressure, or HikariCP saturation.

Database

MySQL

Connection Pool

When MySQL connection pool is exhausted, first compare application pool usage with database max_connections. For HikariCP, check active, idle, pending, and connection acquisition timeout metrics.

Recommended diagnosis:

1. Verify whether HikariCP active connections stay near maximum while pending threads grow.
2. Check MySQL Threads_connected, Threads_running, and max_connections.
3. Inspect slow SQL and long transactions that keep connections checked out.
4. If the database is healthy, look for application connection leaks or missing transaction boundaries.

Use this runbook as evidence for connection pool, max_connections, and HikariCP incidents.