# 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