speeding up django server

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. Runnin开发者_如何学Gog 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!

NOTE: I tried the ab test from another instance and got the same result

Make sure keep-alive is off.

More processes and single-threaded I have seen better performance where CPU is the limiting factor; try processes=4 threads=1.

The best way to tweak mod_wsgi is to not use it :)

First: I don't think your problem is the web server: with mod_wsgi you can get hundreds requests/s. You can get better results with caching and with DB connection pooling. If you're using postgres, take a look at pgpool II: http://pgpool.projects.postgresql.org/ .

However, if you want to go deeper into wsgi web servers, read carefully this nice benchmark: http://nichol.as/benchmark-of-python-web-servers .

If you don't need asyncronous workers, gunicorn is a good choice. It's very easy to setup (you can run it with manage.py run_gunicorn) and it's pretty fast. If you want to be sure that mod_wsgi is not the cuprit, try it. If you want better performance go with gevent or uWSGI.

But the Web Server won't change your benchmark: you can go from 4 req/s to 4.01 req/s.