WebSocket

Reconnection (Always Forget)

• Connections drop silently—TCP FIN may never arrive; don't assume onclose fires
• Exponential backoff: 1s, 2s, 4s, 8s... cap at 30s—prevents thundering herd on server recovery
• Add jitter: delay * (0.5 + Math.random())—prevents synchronized reconnection storms
• Track reconnection state—queue messages during reconnect, replay after
• Max retry limit then surface error to user—don't retry forever silently

Heartbeats (Critical)

• Ping/pong frames at protocol level—browser doesn't expose; use application-level ping
• Send ping every 30s, expect pong within 10s—no pong = connection dead, reconnect
• Server should ping too—detects dead clients, cleans up resources
• Idle timeout in proxies (60-120s typical)—heartbeat must be more frequent
• Don't rely on TCP keepalive—too infrequent, not reliable through proxies

Connection State