A harness and a set of benchmarks for measuring Django's performance over time.

Here's the short version:

mkvirtualenv --no-site-packages djangobench
pip install -e git://github.com/jacobian/djangobench.git#egg=djangobench
svn co http://code.djangoproject.com/svn/django/tags/releases/1.2/ django-control
svn co http://code.djangoproject.com/svn/django/trunk django-experiment
djangobench

Okay, so what the heck's going on here?

First, djangobench doesn't test a single Django version in isolation --that wouldn't be very useful. Instead, it benchmarks an "experiment" Django against a "control", reporting on the difference between the two and measuring for statistical significance.

So to run this, you'll need two complete Django source trees. By default djangobench looks for directories named django-control and django-experiment in the current working directory, but you can change that by using the --control or --experiment options.

Now, because you need two Django source trees, you can't exactly install them: djangobench works its magic by mucking with PYTHONPATH. However, the benchmarks themselves need access to the djangobench module, so you'll need to install it.

If you're feeling fancy, you can use one of them there newfangled DVCSes instead and test against a single repository containing branches:

git clone git://github.com/django/django.git
djangobench --vcs=git --control=1.2 --experiment=master

Git's the only supported VCS right now, but patches are welcome.

At the time of this writing Django's trunk hasn't significantly diverged from Django 1.2, so you should expect to see not-statistically-significant results:

Running 'startup' benchmark ...
Min: 0.138701 -> 0.138900: 1.0014x slower
Avg: 0.139009 -> 0.139378: 1.0027x slower
Not significant
Stddev: 0.00044 -> 0.00046: 1.0382x larger

Benchmarks are very simple: they're a Django app, along with a settings file, and an executable benchmarks.py that gets run by the harness. The benchmark script needs to honor a simple contract:

• It's an executable Python script, run as __main__ (e.g. python path/to/benchmark.py). The subshell environment will have PYTHONPATH set up to point to the correct Django; it'll also have DJANGO_SETTINGS_MODULE set to <benchmark_dir>.settings.
• The benchmark script needs to accept a --trials argument giving the number of trials to run.

• The output should be simple RFC 822-ish text -- a set of headers, followed by data points:

  Title: some benchmark
  Description: whatever the benchmark does
  
  1.002
  1.003
  ...

  The list of headers is TBD.

There's a couple of utility functions in djangobench.utils that assist with honoring this contract; see those functions' docstrings for details.

The existing benchmarks should be pretty easy to read for inspiration. The query_delete benchmark is probably a good place to start.

Please write new benchmarks and send me pull requests on Github!