Cachefly Review

13 March 2007, 17:55

I first heard of Cachefly when they sponsored the diggnation podcast. I was impressed at the download speed of the popular podcast, and did a few tests on their network from various locations around the globe.

For those who don't understand what a CDN is here is a brief overview. Delivery of data on the internet is hindered by distance. The further your data travels to get to the person who requested it the more likely it is to be slowed down (called lag) or lost (called packet loss) by points in various networks that are overloaded or experiencing technical difficulties. There is also an inherent lag in the network caused by the sheer distance its travelling. For instance, its difficult to get the lag between the east coast of America to London below about 70-80 milliseconds. Doesn't sound like much, but it all adds up if your requestor is making hundreds of requests. CDNs get around this my placing the data people may request in many different locations around the globe, and then pointing requestors to the nearest copy. The biggest CDNs claim to run networks on the "edge of the internet", where through partnerships with consumer ISPs they serve content directly from the ISP's own network.

So, I had a few hours spare the other weekend and decided to take them up on their free trial month offer to ease the load on play.tm. Sign up was easy, and the account was setup instantly - FTP, admin tools and the hostname (which is ferrago.cachefly.net). Very impressive. So I got straight on to FTPing up the files.

I'd decided to put the simplest of the site's files on Cachefly - all of the CSS, Javascript includes and static page furniture images. This stuff doesn't take up much disk space (a large cost at Cachefly as they replicate the files onto multiple sets of storage) and doesn't change very often - yet it makes up a very large proportion of the volume of HTTP requests to site. It was a quick win to FTP it all up, then change some variables in the site's config files. The only real negative point on the hosting came up here - in order for the files you're FTPing up to become available at your hostname you have to end the FTP connection. This is annoying, and I'm not sure why you have to do it. It caught me out FTPing one set of files - and I couldn't figure out why they didn't become available.

The stats tools provided by Cachefly are good - showing all the data you would expect from log files, in a useful interface. I love the POP view that lets you see where your files were served from. Its all live information as well, which is impressive for such a distributed system.

In summary then - it all works rather well. The choice of the files to put up was simple given the high prices we would have been paying for them to host the hundreds of gigs of content images and videos. The stats show that a large proportion of hits are served away from our London server farm, so the benefits are obvious. I recommend their service without hesitation.

Jason Cartwright RSS Feed

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Jason is a web developer living in London. My clients include numerous startups, Google, & the BBC.

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