Building Scalable WebSockets for Live Streaming
Real-time interactivity is the core of live streaming, but scaling long-lived WebSocket connections across distributed systems presents unique challenges compared to standard HTTP traffic.
Table of contents:
Redis Pub/Sub Layer
Terminating WebSockets across multiple Node.js instances requires a fast interconnect. We use Redis Pub/Sub to broadcast messages to all instances, routing them to the correct client.
Connection Throttling
To prevent thundering herd problems when a popular stream goes live, we implement exponential backoff and connection batching on the client-side.
Eskimo Connections
WebSockets can drop silently. We implement robust ping/pong keepalives and aggressive reconnection logic to ensure a seamless experience for the viewer.