WebSocket connections enable real-time bidirectional communication but introduce scaling challenges absent in stateless HTTP. Each connection consumes server resources continuously. Horizontal scaling requires message routing across instances. Connection management grows complex at scale.
Connection Management
Each WebSocket connection maintains state on a specific server. Sticky sessions route reconnections to the same server. Connection pooling limits per-client connections. Heartbeats detect dead connections freeing resources. Plan connection limits per server to prevent resource exhaustion.
- Implement sticky sessions using load balancer affinity or tokens
- Use Redis Pub/Sub for message routing across multiple server instances
- Set connection timeouts and implement heartbeat mechanisms
- Monitor connection counts per server preventing overload
- Consider connection limits per user preventing resource abuse
Message Broadcasting
Broadcasting messages to thousands of connections requires efficient fan-out. Redis Pub/Sub distributes messages across servers. Message queues decouple message production from delivery. Room or channel abstractions limit broadcast scope. Optimize message serialization to reduce CPU overhead at scale.