Generally I avoid going down rabbit holes but today I decided to see how deep a particular testing rabbit hole went. This post is a third in what seems be a continuing series of programming anecdotes. It’s not particularly MySQL-related so you can stop reading here unless you grok code stuff.

Before beginning work on issue 720 I ran the mk-table-checksum test suite to make sure it was in working order. No sense writing new tests and code when the old tests and code aren’t reliable. I actually made one seemingly innocuous change to the test suite in preparation for the issue: I changed the –replicate checksum table from MyISAM to InnoDB.

Surprisingly, the test suite proved unstable. Random tests would fail at random times. Some instability was due to new tests for …