Real-Time on David Lang

WebSockets with Node.js: Real-Time Applications

Wed, 30 Jun 2021 00:00:00 +0000

WebSockets provide full-duplex communication over a single TCP connection-ideal for chat, live dashboards, and collaborative editing.

Socket.io Setup

const { Server } = require('socket.io');
const io = new Server(httpServer, { cors: { origin: process.env.CLIENT_URL } });

io.on('connection', (socket) => {
  socket.on('join-room', (roomId) => socket.join(roomId));

  socket.on('message', (payload) => {
    io.to(payload.roomId).emit('message', payload);
  });
});

Scaling Considerations

Use Redis adapter for Socket.io when running multiple server instances. Sticky sessions or shared pub/sub keep room state consistent.