Node.js, multi-threading and Socket.io

Question

I\'m looking to get Socket.io to work multi-threaded with native load balancing (\"cluster\") in Node.js v.0.6.0 and later.

From what I understand, Socket.io uses Re

Answer 1

Actually your code should look like this:

var cluster = require('cluster');
var http = require('http');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }
} else {
  var sio = require('socket.io')
  , RedisStore = sio.RedisStore
  , io = sio.listen(8080, options);

  // Somehow pass this information to the workers
  io.set('store', new RedisStore);

  // Do the work here
  io.sockets.on('connection', function (socket) {
    socket.on('chat', function (data) {
      socket.broadcast.emit('chat', data);
    })
  });
}

Another option is to open Socket.IO to listen on multiple ports and have something like HAProxy load-balance stuff. Anyway you know the most important thing: using RedisStore to scale outside a process!

Resources:

http://nodejs.org/docs/latest/api/cluster.html
How can I scale socket.io?
How to reuse redis connection in socket.io?
Node: Scale socket.io / nowjs - scale across different instances
http://delicious.com/alessioaw/socket.io