Cluster script for running multiple node processes

cluster.js

#!/usr/bin/env node

var cluster = require('cluster');
var WORKERS = require('os').cpus().length;

console.debug = function(msg) {
  console.log('%s %s', new Date().toISOString(), msg);
}

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

  process.on('SIGUSR2', function() {
    var workers = Object.keys(cluster.workers);
    console.debug('SIGUSR2 with ' + workers.length + ' workers running');

    // Bring up a new fleet of workers
    for (var i = 0; i < WORKERS; i++) { cluster.fork(); }

    workers.forEach(function(id) {
      var worker = cluster.workers[id];
      if (worker.killing) { return; }

      console.debug('Disconnecting worker ' + worker.id);
      worker.disconnect();
      worker.killing = true;

      var timeout = setTimeout(function() {
        console.debug('Force killed worker ' + worker.id);
        worker.kill();
      }, 60000);

      worker.on('disconnect', function() {
        clearTimeout(timeout);
        console.debug('Worker ' + worker.id + ' disconnected');
        worker.destroy();
      });
    });
  });

  cluster.on('exit', function(worker, code, signal) {
    // Suicide is true after kill() or disconnect()
    if (!worker.suicide) {
      console.debug('Worker ' + worker.id + ' died unexpectedly, forking another');
      cluster.fork();
    }
  });

} else {
  var server = require("./index.js");
  server.listen(process.env.NODE_PORT || 8080);
}