Alex Rivera | Logout

Azure CDN - Enabling HTTP Compression - Hosted Web Role

Asked 2012-05-02T19:00:29.930
11

Has anyone successfully configured Azure CDN for HTTP compression using their hosted web role? We are having trouble compressing HTTP content at the Azure edge servers. The CDN is only caching the uncompressed version of the content.

If we hit our resource link (webresource.axd) from a non-Azure approach it compresses via gzip (using the xxxx.cloudapp.net/cdn/webresource.axd) as expected. However, as soon as we point our resource link to Azure CDN (xxxx.vo.msecnd.net), the content is served up uncompressed, despite the browser telling the Azure CDN it accepts gzip.

I posted this same issue to Azure Forums, but nobody has responded as of yet.

While troubleshooting the problem, it appears that the Azure CDN is stripping out the Accept-Encoding HTTP header. Just curious if others have had this same issue.

Azure CDN Best Practices states...

How does the Windows Azure CDN work with compressed content?

The Windows Azure CDN will not modify (or add) compression to your objects. The Windows Azure CDN respects whatever compression is provided by the origin based on the "Accept-Encoding" header. As of 1.4, Azure Storage does not support compression. If you are using hosted-service object delivery, you can configure IIS to return compressed objects.

What we are seeing is that the CDN is not respecting the origin Accept-Encoding, it's being stripped awa

azure cdn azure-web-roles azure-cdn
Edit
Report

1 Answer

4

CDN picks up compression from the origin and Windows Azure Storage does not support compression directly so if you get CDN content from Azure Storage origin, it will not be compressed. So if you have content hosted at Windows Azure Storage you will not be able to have compressed content. To have compressed content, you would need to host the content at hosted service such as web role as origin. As this type of origin would be IIS based, is a supported way to use compression.

Windows Azure CDN supports compressed content over HTTP1.0, and most of the time the problem I have seen are related with having an HTTP 1.0 vs HTTP 1.1 issue. So when you request you CDN object directly from your web role via HTTP 1.0 (using the wget command) you should get compressed content if all is correct. If you get non-compressed content then you know where the problem is. Please be sure you’ve configured your application and IIS itself to deliver compressed content to HTTP 1.0 clients as well as HTTP 1.1 clients.

I have written a detailed blog entry to exactly add HTTP Compression with Azure CDN through Web role:

http://blogs.msdn.com/b/avkashchauhan/archive/2012/03/05/enableing-gzip-compression-with-windows-azure-cdn-through-web-role.aspx

answered 2012-05-02T19:08:35.860

Your Answer