run.js

var fork = require('child_process').fork;
var server, heartbeat; 

function startServer () {
  console.log('Starting server');
  server = fork('insight');

  //when the server goes down restart it
  server.on('close', function(code) {
    startServer();
  });

  //when server sends a heartbeat message save it
  server.on('message', function(message) {
    heartbeat = message ? message.heartbeat : null;
  });

  //ask the server for a heartbeat
  server.send({request: 'heartbeat'});

  //wait 5 seconds and check if the server responded
  setTimeout(checkHeartbeat, 5000);
}

function checkHeartbeat() {
  if(heartbeat) {
    console.log('Server is alive');

    //clear the heart beat and send request for a new one
    heartbeat = null; 
    server.send({request: 'heartbeat'});

    //set another hearbeat check
    setTimeout(checkHeartbeat, 5000);

  } else {
    console.log('Server looks stuck...killing');
    server.kill();
  }
}

startServer();