One of the many recommendations that Yahoo makes on optimizing your web site for high amounts of traffic, and to make the response time speedier to your user is GZip encoding all your static content. I usually do this as a standard for setting up any of my Web Servers, in addition to setting expiration headers on my static content, to ensure that I am serving as little content as possible.
I found Rick Strahl's post on this very subject that he wrote up about a 9 months ago. It was helpful in diagnosing my problem, however it didn't solve it. The HTTP compression is configured in IIS 7.0's ApplicationHost.config file (
c:\windows\system32\inetsrv\config\applicationhost.config), see below for the default settings:
As you can see anything that starts with the MIME type of
message is GZip encoded just fine. However there is also
However the problem comes in when you look at the default MIME type mappings setup, in the same ApplicationHost.config file, a little further down.
However that didn't work either, and it should have because the MIME type now matched my compression MIME type. I even verified the MIME type in fiddler. So I then tried my last option to change the MIME type to