node-http-proxy/examples/balancer/simple-balancer.js

var http = require('http'),
    httpProxy = require('../../lib/http-proxy');
//
// A simple round-robin load balancing strategy.
// 
// First, list the servers you want to use in your rotation.
//
var addresses = [
  {
    host: 'ws1.0.0.0',
    port: 80
  },
  {
    host: 'ws2.0.0.0',
    port: 80
  }
];
var proxy = httpProxy.createServer();

http.createServer(function (req, res) {
  //
  // On each request, get the first location from the list...
  //
  var target = { target: addresses.shift() };

  //
  // ...then proxy to the server whose 'turn' it is...
  //
  console.log('balancing request to: ', target);
  proxy.web(req, res, target);

  //
  // ...and then the server you just used becomes the last item in the list.
  //
  addresses.push(target);
}).listen(8000);

// Rinse; repeat; enjoy.