node built-in cluster and http-proxy

app.js

/**
 * Module dependencies.
 */

var express = require('express')
  , routes = require('./routes')
  , http = require('http')
  , cluster = require('cluster')
  , numCPUs = require('os').cpus().length
  , argv = require('optimist').argv
  ;

var host = argv.host || 'localhost';
var port = argv.port || 3000;

var app = express();



app.configure(function(){
  app.set('views', __dirname + '/views');
  app.set('view engine', 'jade');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.static(__dirname + '/public'));
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(app.router);
});

app.configure('development', function(){
  app.use(express.errorHandler());
});

app.get('/', routes.index);

var cluster = require('cluster');

if(cluster.isMaster) {
  for (var i = 0; i < 4; i++) {
     cluster.fork();
   }
   cluster.on('death', function(worker) {
     console.log('worker ' + worker.pid + ' died');
   });
} else {
  http.createServer(app).listen(port, host);
  console.log('app pid : ' + process.pid);
}

proxy-app.js

/**
 * Module dependencies.
 */

var express = require('express')
  , routes = require('./routes')
  , http = require('http')
  , argv = require('optimist').argv
  ;

var host = argv.host || 'localhost';
var port = argv.port || 3000;
var app = module.exports = express();

app.configure(function(){
  app.set('views', __dirname + '/views');
  app.set('view engine', 'jade');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.static(__dirname + '/public'));
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(app.router);
  
});

app.configure('development', function(){
  app.use(express.errorHandler());
});


app.get('/', routes.index);

cluster = require('cluster');


if(cluster.isMaster) {
  for (var i = 0; i < 4; i++) {
     cluster.fork();
  }
  cluster.on('death', function(worker) {
   console.log('worker ' + worker.pid + ' died');
  });
} else {
  http.createServer(app).listen(port, host);
  console.log('proxy-app pid : ' + process.pid);
}

proxy.js

var express = require('express')
  , routes = require('./routes')
  , http = require('http')
  , httpProxy = require('http-proxy')
  , cluster = require('cluster')
  , numCPUs = require('os').cpus().length
  , cp = require('child_process')
  ;

var options = {
  router: {
    'localhost/foo': 'localhost:3002',
    'localhost': 'localhost:3001'
  }
}

if(cluster.isMaster) {
  cp.fork(__dirname + '/app.js', ['--port=3001', '--host=localhost']);
  cp.fork(__dirname + '/proxy/proxy-app.js', ['--port=3002', '--host=localhost']);
  for (var i = 0; i < 2; i++) {
    cluster.fork();
  }
  cluster.on('death', function(worker) {
    console.log('worker ' + worker.pid + ' died');
  });
} else {
  var proxyServer = httpProxy.createServer(options);
  proxyServer.listen(3000);
  console.log('proxy worder pid : ' + process.pid);
}