Should I use a GZIP compression middleware or not?

Question

Having worked with Django, I've seen that people tend to reccommend the use of GZIP Middleware to compress HTML pages.

However, the WSGI v1.0 specification tells us:

(Note: applications and middleware must not apply any kind of Transfer-Encoding to their output, such as chunking or gzipping; as "hop-by-hop" operations, these encodings are the province of the actual web server/gateway. See Other HTTP Features below, for more details.)

This suggests that compression should be left to the server/gateway. Which makes sense, as the server is probably much faster in doing that. Also, it might prefer SDCH over gzip, as most modern Chrome/Chromium browsers support it.

So my question remains, should I use a middleware to compress my responses or not? Specifically, what is the right choice for Google App Engine?

EDIT:

The Pylons Book also contains an example gzip middleware.

I didn't mention that my framework of choice is Pyramid (ex-repoze.bfg).

Answer 1

App Engine already does compress the content, if the client supports it.

If the client sends HTTP headers with the request indicating that the client can accept compressed (gzipped) content, App Engine compresses the response data automatically and attaches the appropriate response headers. It uses both the Accept-Encoding and User-Agent request headers to determine if the client can reliably receive compressed responses. Custom clients can force content to be compressed by specifying both Accept-Encoding and User-Agent headers with a value of "gzip".