Last week I had to confront one of those situations where you can’t really tell what is going on with a piece of software, and the final conclusion would sound completely crazy if postulated as the initial hypothesis. The regular MySQL commands and utilities fall short in these cases, so I had to resort to the three tools reviewed in this article.
The problem we were diagnosing was this: at some point in time, a number of queries that use to take less than one minute to execute, started to take between five to 15 minutes. We needed to get an insight into what was going on inside the MySQL server.
At some point in a long diagnosis process, MySQL’s
SHOW [GLOBAL] VARIABLES and
SHOW [GLOBAL] STATUS are nothing more than a long list of numbers. Going through a team mate’s notes on another issue, I came