gistfile1.js

var cluster = require('cluster');                 

if (cluster.isMaster) {                           
  var numCPUs = require('os').cpus().length;      
  
  console.log(numCPUs);                           

  for (var i = 0; i < numCPUs; i++) {             
    cluster.fork();                               
  }                                               
  
  cluster.on('exit', function (worker) {          
    console.log('worker ' + worker.process.pid +  
      ' died. Trying to respawn...');             
    cluster.fork();                               
  });                                             
} else {                                          

  require('newrelic');                          
  var express = require('express'),
  // ... rest of express app here
}