Asynchronous http calls with nodeJS - node.js

Question

I would like to launch asynchronous http calls on my server node, i saw the async node module and i guess the async.parallel enables us to do that.
The documented example is pretty clear, but i don't know how i could manage multiple http calls.
I tried the example bellow but it doesn't even launch the http calls:
var http = require('http');
var Calls = [];
Calls.push(function(callback) {
// First call
http.get('http://127.0.0.1:3002/first' callback);
});
Calls.push(function(callback) {
// Second call
http.get('http://127.0.0.1:3002/second' callback);
});
var async = require('async');
async.parallel(Calls, function(err, results) {
console.log('async callback: '+JSON.stringify(results));
res.render('view', results);
});
If i launch the http requests separately, i do have a result, but but calling the async callback i get async callback: [null,null]

Answer 1

Have a look at the documentation:
With http.request() one must always call req.end() to signify that
you're done with the request - even if there is no data being written
to the request body.
You are creating a request, but you are not finalizing it. In your calls you should do:
var req = http.request(options, function(page) {
// some code
});
req.end();
This is assuming you are doing a normal GET request without body.
You should also consider using http.get which is a nice shortcut:
http.get("http://127.0.0.1:3002/first", function(res) {
// do something with result
});
Update The other thing is that callbacks in async have to be of the form
function(err, res) { ... }
The way you are doing it now won't work, because callback to http.get accepts only one argument res. What you need to do is the following:
http.get('http://127.0.0.1:3002/second', function(res) {
callback(null, res);
});

Answer 2

Ok the thing is to call the callback this way callback(null, res); instead callback(res);, i think the first parameter is interpreted as an error and the second one is the real result.

Answer 3

dont use capital names for other purpouses than types/classes
below is your code with corrected obvious mistakes
var http = require('http');
var calls = [];
calls.push(function(callback) {
// First call
http.get('http://127.0.0.1:3002/first', function (resource) {
resource.setEncoding('utf8');
resource.on('data', function (data) {
console.log('first received', data);
callback();
});
});
});
calls.push(function(callback) {
// Second call
http.get('http://127.0.0.1:3002/second', function (resource) {
resource.setEncoding('utf8');
resource.on('data', function (data) {
console.log('second received', data);
callback();
});
});
});
var async = require('async');
async.parallel(calls, function(err, results) {
console.log('async callback ', results);
res.render('view', results);
});