Sample of NodeJS as a cluster

index.js

/*
 *  Cluster NodeJS
 */

var cluster = require('cluster');

if (cluster.isMaster) {

    var cpuCount = require('os').cpus().length;

    for (var i = 0; i < cpuCount; i += 1) {
        cluster.fork();
    }

} else {

    var http = require('http');

    http.createServer(function (req, res) {
      res.end('Hello world!');
    }).listen(9615);
}