Node cluster sample

cluster.js

var cluster = require('cluster'),
    http = require('http'),
    numCPUS = require('os').cpus().length;

if (cluster.isMaster){
    for (var i=0; i< numCPUS; i++){
        cluster.fork();
    }

    cluster.on('death', function(worker){
        console.log('Worker ' + worker.pid + ' died. Bringing another one up!');
        cluster.fork();
    });
}
else{
    http.Server(function(req, res) {
        res.writeHead(200);
        res.end(process.env.NODE_WORKER_ID + ": hello world\n");
    }).listen(8000);
}