cluster throttle idea

cluster-throttle.js

var utils = require('cluster/lib/utils');
var redis = require('redis');
var rc = redis.createClient();

exports = module.exports = function(options) {
	
	ratelimit.enableInWorker = true;
	options = options || {};
	
	var interval = options.interval = (options.interval || 1);
	
	var now = function () {
		return (new Date).getTime() / 1000;
	};
					
	function ratelimit(master) {
		var server = master.server;
		var listeners = server.listeners('request');
			
		if (master.isWorker) {
			server.removeAllListeners('request');
			server.on('request', function(req, res) {
				var ctx = this;
				var id = req.connection.remoteAddress + req.headers['user-agent'];
					
				rc.getset(id, now(), function(err, then) {
					if (then && (now() - then) < interval) {
						res.writeHead(500);
						res.end();
					} else {
						listeners.forEach(function(fn) {
							fn.call(ctx, req, res);
						});
					}
				});
			});
		}
	}
	
	return ratelimit;
	
};