I’m really not sure how I missed out on some of this stuff for so long, but I just came across some MySQL tools from the fine folks at Percona that I’ve been digging into over the last couple of days. I’ve already gotten a lot of use out of the Percona toolkit stuff, particularly pt-query-advisor and pt-variable-advisor. I’m also looking very closely at their monitoring plugins; they already have plugins for nagios and cacti, and I’m curious if these plugins can be adapted for using with newrelic.
Finally, and I have no idea how I managed to not hear about this until now, innotop also looks extremely useful.
Certainly you can do everything these tools do by hand yourself, and that’s what I’ve done: monitor load, memory usage, the slow query log and judicious use of EXPLAIN, that sort of thing. I’m pretty stoked about being able to make these tasks easier though.