CDN (Content delivery network), as Wikipedia states, is a group of computers spread across the Internet who collaborate together to deliver content. In this post I'll tell you a bit about our experience trying to setup a CDN for Teamness.Image by GustavoG
The benefit of using CDN when you're offering a live web application is that you can delegate your static data, like images, movies, client scripts and such to be delivered from different points in the world. This translates in higher download speed for your users. When someone requests a page from your application, she/he's redirected to the nearest server in the CDN to have the static content delivered.
We are strong believers in the concept of Try-Before-You-Buy. That's why we setup a demo account for Teamness and it's also a reason why we're offering a free plan. We applied for trial versions from two offerers: Panther Express and EdgeCast.
They advertise having under 40ms delay for 95% of the computers in the world, but a problem for us was that Panther Express don't deliver content over HTTPS, or at least they didn't until the end of May 2008, when we were discussing with them.
We obtained a trial setup for one week, but the fact that we didn't get HTTPS content was a major issue.
We signed a Master Service Agreement and a Service Order for a 4-days trial. They mentioned that they don't support CNAME’s for HTTPS, but only for HTTP.
After trial thoughts
Our intention was to sign up for a trial version, so we can run some tests and see what's the improvement of using a CDN service. We made different tests, adjusting the number of concurrent users and using also SSL content for EdgeCast case, but we did't obtain better results with CDN than with our server setup at SoftLayer.
Both Panther Express and EdgeCast asked for some sample URLs to check HTTP headers, so if you want to test a CDN solution before releasing, it's better to have your application online already. This is also helpful for doing comparative tests between your application with and without CDN enabled.
We will come back to evaluate more CDN offers in the future. In the mean time, our hosting provider SoftLayer started to offer CDN services and there is also another affordable solution we found at CacheFly. Here you can find a CDN guide with services ranked by approximate annual revenue, via CDN Evangelist.