Node.js http request memory and cpu hog - node.js

Question

I have a node.js script that continuously requests a page, sort of like a cron job.
However, after a few minutes Node starts to use a lot of CPU (up to 70%) and memory (up to 200mb).
What is wrong with my script?
function cron(path)
{
var http = require('http');
var site = http.createClient(443, 'www.website.com', true);
var request = site.request('GET', path, {'host': 'www.website.com'});
request.end();
request.on('response', function (response) {
setTimeout(function(){cron(path)},15000);
});
}
cron('/path/to/page');

Answer 1

request.on('response', function (response) {
setTimeout(function(){cron(path)},15000);
});
For every response you create a new cron job. Log your responses. If your getting more then 1 from your request then your exponantially creating more cron jobs.
Your creating a function() {} with a reference to path. So the entire scope state is kept. you want to free memory by adding this:
var site = null;
var request = null;
Your calling require("http") inside a function rather then outside in module scope. You only need to get http once so place at the top of your file in module scope.
var http = require('http');
var site = http.createClient(443, 'www.website.com', true);
function cron(path)
{
var request = site.request('GET', path, {'host': 'www.website.com'});
request.end();
var once = true;
request.on('response', doIt);
function doIt(response) {
if (!once) {
once = null;
doIt = function() {};
setTimeout(function(){cron(path)},15000);
}
});
site = null;
request = null;
}
cron('/path/to/page');

Answer 2

In addition to the tips from #Raynos, here's another. I find that recursive calls like this in long running processes make me a bit nervous so I'd err on the side of using setInterval instead. I'd maybe split the cron and the http behaviour apart in case you want to try and re-use that logic, although that'll depend on your context:
e.g. in node 0.4.7:
var https = require('https');
function poll(path)
{
https.get({
host: 'www.website.com',
port: 443,
path: path
}, function(res) {
console.log("Got response: " + res.statusCode);
}).on('error', function(e) {
console.log("Got error: " + e.message);
});
}
function cron(path)
{
return setInterval(function(){
poll(path);
},15000);
}
var intervalId = cron('/path/to/page'); // keep in case you need to use clearInterval