Proofs of Concept Last week at the MySQL conference in Santa Clara, I presented some slides on our work towards group commit on the MySQL binlog. We examined the effects of not holding the prepare_commit_mutex across the binlog fsync, combining this with a timed wait on a condition variable to enable binlog group commits, and then we explored the effect of releasing row locks during the prepare step instead of in the commit step.

The proof-of-concept code I worked on up to that point made me very quite familiar with the parts of the MySQL codebase that these changes are in. Energized by the MySQL conference, I got to work on writing some production-quality patches that are taking Facebook's MySQL 5.1 towards the performance gains we discussed at the conference.

Patches for Production The first step was to set up some new performance monitoring so we could understand the effects of the changes as we made them. The first patch keeps …