connection-pool-management

name	connection-pool-management
description	Pool sizing, connection lifetime, health checks, and resource exhaustion prevention.

Connection Pool Management

Managing database connections efficiently to maximize throughput and prevent resource exhaustion.

Context

You are configuring connection pools. Size appropriately; monitor usage.

Domain Context

• Pool Size: How many concurrent connections? Too few = waits; too many = resource exhaustion
• Connection Lifetime: How long should connection live? Connections age, become stale
• Health Checks: Validate connections before reuse
• Idle Timeout: Close unused connections; free resources
• Queuing: What happens when all connections are busy?

Instructions

1. Min/Max Size: Min = base connections; Max = peak + buffer
2. Max = (Number of Cores * 2) + Extra for I/O: Rule of thumb
3. Connection Lifetime: 30 minutes common; depends on database
4. Idle Timeout: 5 minutes; reclaim unused connections
5. Health Checks: Ping connection before using; catch stale connections
6. Queue Size: What happens if all connections busy? Queue or error?
7. Monitoring: Track pool utilization, wait times

Anti-Patterns

• Pool too small; queries wait forever
• Pool too large; resource exhaustion, slow start
• No health checks; stale connections cause errors
• No idle timeout; connections accumulate, eventually exhaust
• Not monitoring; don't know if pool is too small

Further Reading

• HikariCP documentation (Java)
• Connection pool best practices (AWS)
• Database connection tuning guides