nombo-balancer.node.js

var cluster = require('cluster');
var LoadBalancer = require('loadbalancer');

var balancer;

if (cluster.isMaster) {
	process.on('message', function (m) {
		var balancers; 
		if (m.type == 'init') {
			var balancerCount = m.data.balancerCount;
			balancers = [];
			
			var launchBalancer = function (i) {
				balancer = cluster.fork();
				balancers[i] = balancer;
				balancer.on('error', function (err) {
					process.send({
						message: err.message,
						stack: err.stack
					});
				});
				
				balancer.on('message', process.send.bind(process));
				balancer.on('exit', function () {
					launchBalancer(i);
				})
				balancer.send(m);
			};

			for (var i=0; i<balancerCount; i++) {
				launchBalancer(i);
			}
		} else {
			for (var i in balancers) {
				balancers[i].send(m);
			}
		}
	});
} else {	
	var handleError = function (err, notice) {
		var error;
		if (err.stack) {
			error = {
				message: err.message,
				stack: err.stack
			};
		} else {
			error = err;
		}
		process.send({type: notice ? 'notice' : 'error', data: error});
		if (err.code != 'ECONNRESET') {
			process.exit();
		}
	};
	
	var handleNotice = function (err) {
		handleError(err, true);
	};
	
	process.on('message', function (m) {
		if (m.type == 'init') {
			balancer = new LoadBalancer(m.data);
			balancer.on('error', handleError);
			balancer.on('notice', handleNotice);
		} else if (m.type == 'setWorkers') {
			balancer.setWorkers(m.data);
		}
	});
}