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 Redis to store its internal data. My understanding is this: instead of spawning a new Redis instance for every worker, we want to force the workers to use the same Redis instance as the master. Thus, connection data would be shared across all workers.

Something like this in the master:

RedisInstance = new io.RedisStore;

The we must somehow pass RedisInstance to the workers and do the following:

io.set('store', RedisInstance);

Inspired by this implementation using the old, 3rd party cluster module, I have the following non-working implementation:

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();

  }



  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);



} else {

  // Do the work here

  io.sockets.on('connection', function (socket) {

    socket.on('chat', function (data) {

      socket.broadcast.emit('chat', data);

    })

  });

}

Thoughts? I might be going completely in the wrong direction, anybody can point to some ideas?