kb/db_connection_pool.md

Database Connection Pool Exhaustion

Symptoms

• too many connections, connection refused, or pool timeout errors
• Spikes in DB connections and wait time
• Slow queries or lock contention observed

Checks

• Inspect application pool size vs database max connections
• Review slow queries and transaction lengths
• Check connection leak metrics and proper closing
• Validate DB host/port/DNS and TLS settings
• Examine recent traffic/load changes

Fix

• Tune pool size and DB max connections
• Fix connection leaks and ensure pooling is enabled
• Optimize slow queries; add indexes where needed
• Scale database or replicas to handle load