request all the things

index.js

var async = require('async');
var request = require('request').defaults({
  time: true
});
var urls = [
  'http://www.example.com'
  // ... 5000 URLs
];
 
async.each(urls, function(url, done) {
  request(url, function(err, res, body) {
    console.log(url, res.elapsedTime + 'ms');
    done();
  });
}, function() {
  console.log('fini');
});

res.elapsedTime only ever increases - despite the server maintaining a constant response time