python - In production, Apache + mod_wsgi or Nginx + mod_wsgi?

Question

What to use for a medium to large python WSGI application, Apache + mod_wsgi or Nginx + mod_wsgi?

Which combination will need more memory and CPU time?
Which one is faster?
Which is known for being more stable than the other?

I am also thinking to use CherryPy's WSGI server but I hear it's not very suitable for a very high-load application, what do you know about this?

Note: I didn't use any Python Web Framework, I just wrote the whole thing from scratch.
Note': Other suggestions are also welcome.

Answer 1

For nginx/mod_wsgi, ensure you read:

http://blog.dscpl.com.au/2009/05/blocking-requests-and-nginx-version-of.html

Because of how nginx is an event driven system underneath, it has behavioural characteristics which are detrimental to blocking applications such as is the case with WSGI based applications. Worse case scenario is that with multiprocess nginx configuration, you can see user requests be blocked even though some nginx worker processes may be idle. Apache/mod_wsgi doesn't have this issue as Apache processes will only accept requests when it has the resources to actually handle the request. Apache/mod_wsgi will thus give more predictable and reliable behaviour.