InsideEdgeInsideEdge
Download App

Phase 14 · Real-time Communication

Topics

Real-time Scaling Challenges

Part of the Backend Developer Roadmap.

Summary

The specific difficulties of scaling WebSocket connections horizontally — since a client stays connected to one specific server instance, broadcasting to all clients requires coordination across instances.

How to Learn This

  • 1Diagram the problem: a message needs to reach clients connected to different server instances.
  • 2Learn how a Redis pub/sub adapter solves this for Socket.io across multiple instances.
  • 3Understand sticky sessions and why load balancers need special config for WebSocket traffic.

Previous

Pub/Sub Pattern

Next

Real-time Chat App

More topics in Real-time Communication

WebSocketsSocket.ioServer-Sent EventsLong PollingPub/Sub Pattern
InsideEdge

Stuck on this topic? Ask an Insider

Get 1:1 guidance from people who've walked this exact path — free on the InsideEdge app.

Download
InsideEdge