scalable socket.io with redis and node-http-proxy

gistfile1.js

// balancer node
var httpProxy = require('http-proxy');
var uuid = require('node-uuid');
var Cookies = require('cookies');
var redis = require('redis');
var connect = require('connect');
var express = require('express');
var RedisStore = require('connect-redis')(express);
var redisClient = redis.createClient();
var port = 8000;

// available servers
var targets = [
  { host: '127.0.0.1', port: 8090 },
  { host: '127.0.0.1', port: 8091 },
  { host: '127.0.0.1', port: 8092 },
  { host: '127.0.0.1', port: 8093 }];

// redis session store
var session = {
  secret: 'secret',
  key: 'express.sid',
  store: new RedisStore({ client: redisClient })
};

// build proxies
var proxies = targets.map(function(target) {
  return new httpProxy.HttpProxy({ target: target });
});

var proxiesHash = {};
var app = express.createServer(express.logger());

app.get('/socket.io/:ver', function (req, res) {
  var cookies = new Cookies( req, res);
  var cookie = cookies.get('ws');

  if (!cookie) {
    cookie = uuid.v1();
    cookies.set('ws', cookie);
  }

  if (!proxiesHash[cookie]) {
    var proxy = proxies.shift();
    proxiesHash[cookie] = proxy;
    proxies.push(proxy);
  }

  proxiesHash[cookie].proxyRequest(req, res);
});

// configure express
app.configure(function () {
  app.use(express.cookieParser());
  app.use(express.logger('dev'));
  app.use(express.methodOverride());
  app.use(express.session(session));
  app.use(connect.compress());
  app.use('view engine', 'html');
  app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
  app.use(express.static(__dirname + '/public'));
});

app.on('upgrade', function (req, socket, head) {
  var cookies = new Cookies(req);
  var cookie = cookies.get('ws');
  if (!proxiesHash[cookie]) return;
  proxiesHash[cookie].proxyWebSocketRequest(req, socket, head);
});

app.listen(port);

// ----------------------------------------------------------------
// server node
var redis = require('redis');
var sio = require('socket.io');
var RedisStore = sio.RedisStore;
var port = parseInt(process.argv[2]) || 8090;
var io = sio.listen(port);

io.set('store', new RedisStore({
  redisPub: redis.createClient(),
  redisSub: redis.createClient(),
  redisClient: redis.createClient()
}));

io.sockets.on('connection', function (socket) {
  socket.on('ping', function (data) {
    socket.broadcast.emit('pong', data);
  });
});

// --------------------------------------------------------------
// client node
var port = 8000;
var io = require('socket.io-client');
var socket = io.connect('http://localhost:' + port);

socket.on('connect', function () {
  socket.emit('ping', 'hi from client: ' + port);
});

socket.on('pong', function (data) {
  console.log(data);
});

// start balancer
node balancer.js

// start 2 servers on port 8090 and 8091
node server.js 8090
node server.js 8091

// access http://127.0.0.1:8080