nodeTimerDemo.js

var cluster=require('cluster');

if(cluster.isMaster){
	console.log('is master');
	var worker=cluster.fork();
	worker.on('message',function(message){
		console.log('master recieve message: '+message);
	});
	process.on('exit',function(){
		console.log('process exit');
	});
}else{
	console.log('is slave');
	
	setInterval(function(){
		process.send('are u ok, master?');
	},5000);
}

console.log('end.');