Scalability and Load Testing - Week 2

I didn't manage to accomplish as much as I had hoped in the past week, but regardless, did make some progress. I started a new module (loadtest.module) that adds timing to simpletest (with a small, <10 line patch to simpletest) and records the length of time and characteristics of the test (i.e. enabled modules) to the database. I'm now working on code to automatically enable and disable modules and run tests at each iteration. This will hopefully be useful in determining modules that are generating serious bottlenecks in the site.

The other major aspect which I've only made minimal progress on is designing the load tests. What needs to be tested? What info needs to be recorded about the tests in order for them to be useful? How much data should be generated on the site (i.e. nodes, comments, etc.) to make the test "fair"? Right now I'm kind of thinking that designing tests around the different hooks Drupal allows might be a good starting point.