index.js

/**
 * Created by alexn on 14/11/2017.
 */
var pm2 = require('pm2');

var instances = process.env.WEB_CONCURRENCY || -1; // Set by Heroku or -1 to scale to max cpu core -1
var maxMemory = process.env.WEB_MEMORY || 512; // " " "

pm2.connect(function() {
  pm2.start({
    script: './bin/www',
    name: 'FootballQuiz', // ----> THESE ATTRIBUTES ARE OPTIONAL:
    exec_mode: 'cluster', // ----> https://github.com/Unitech/PM2/blob/master/ADVANCED_README.md#schema
    instances: 3,
    max_memory_restart: maxMemory + 'M', // Auto restart if process taking more than XXmo
  }, function(err) {
    if (err) return console.error('Error while launching applications', err.stack || err);
    console.log('PM2 and application has been succesfully started');

    // Display logs in standard output
    pm2.launchBus(function(err, bus) {
      console.log('[PM2] Log streaming started');

      bus.on('log:out', function(packet) {
        console.log('[App:%s] %s', packet.process.name, packet.data);
      });

      bus.on('log:err', function(packet) {
        console.error('[App:%s][Err] %s', packet.process.name, packet.data);
      });
    });
  });
});