speeding up django server

Question

My setup is django 1.3 and the default mod_wsgi and apache packages for ubuntu 10.04. I tested one view of my app on my development VM (DEBUG and debugging toolbar off):

ab -n 200 -c 5 http://127.0.0.1/ 

and got 4 requests per second. This seemed slow so I simplified the queries, used indexes, etc. to the point where debugging toolbar tells me I have 4 queries taking 8ms. Running the same test, I only get 8 requests per second. The CPU seems to be at 100% the whole time. This seems quite slow for what is now a quite simple view, but it is just a low powered VM.

I decided to start up a large ec2 instance (4 cpu) to see what kind of performance I would get on that class of machine and was surprised to only get 13 requests per second. How can I change the configuration of apache/mod_wsgi to get more performance out of this class of machine?

I think I am using worker rather than prefork:

$ /usr/sbin/apache2 -l Compiled in modules: core.c mod_log_config.c mod_logio.c worker.c http_core.c mod_so.c 

My worker configuration is:

<IfModule mpm_worker_module> StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 150 MaxRequestsPerChild 0 </IfModule> 

and my WSGI settings look like this:

WSGIScriptAlias / /home/blah/site/proj/wsgi.py WSGIDaemonProcess blah user=blah group=blah processes=1 threads=10 WSGIProcessGroup blah 

Thanks very much for your help!

Answer 1

Increase WSGIDaemonProcess procecesses to at least twice the number of cpus and try again