Above The Cloud

* Update: Please note this article is now redundant. Please defer instead to this clarification: Azure CDN Updated

The pricing structure for the CDN aspect of Windows Azure has just been announced. You may remember that I previously wrote about Global Foundation Services and the mechanism that Microsoft uses to globally distribute its own content. Since CDN might become more interesting to you now that it is officially released, I thought I’d summarise two important points.

CDN Data Is Not On Microsoft Networks

I did cover this in greater detail in the previous post about GFS mentioned above; Microsoft does not have a CDN of their own and 3rd party services are utilised to achieve this. While I don’t see it generally being a problem, this might bother some people, mostly the fact that they can’t be sure where their data is actually sitting when it is cached in a CDN node.

You Pay Twice

CDN nodes are not part of the Microsoft network, therefore you will pay for output data transaction and bandwidth from the Azure Storage service, as well as for connections to CDN node. This means you are really paying a premium for this service. To quote the original release:

Any data transfers and storage transactions incurred to get data from Windows Azure Storage to the CDN will be charged separately at our normal Windows Azure Storage rates.

You have been warned!