I’m developing webapplications running under mod_python for a long time. I’m not very satisfied with the mod_python performance particularly the first load time so I’m looking for something like an application server – loaded modules will stay “longer” in the memory – application doesn’t need to be completely initialized very often. The FastCGI approach is very close. I ran benchmarks to measure overhead of the FastCGI (mod_fastcgi, mod_fcgid) compared to the mod_python.

configuration: Mobile AMD Sempron 3100+, Ubuntu Hardy, Ubuntu’s version of fcgid is segfaulting so I borrowed the module from Debian Lenny, mods are in the default configuration, no tweaking

Benchmarking methodics:

• many keep-alive requests

  # ab -k -c 1 -n 10000 http://lo/...

• startup time

  # /etc/init.d/apache2 restart
  # sleep 1
  # ab -c 1 -n 1 http://lo/...

• concurrent access

  # ab -c 30 -n 5000 http://lo/...

Simple “hello world”

mod_python:

from mod_python import apache

def handler(req):
    req.content_type = 'text/plain'
    req.write("Hello World!")
    return apache.OK

FastCGI:

from fcgi import WSGIServer

def myapp(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    yield 'Hello World!\n'

WSGIServer(myapp).run()

results:

Summary

Result is that the overhead difference is almost insignificant.  mod_fcgid seems to be a good adept.

Next time I will focus more on tuning the FastCGI implementations and solutions for larger applications (longer load time).