I’ve been wanting a query sniper for a while for MySQL (some people seem to call them “query killers”). They’re basically programs which inspect the MySQL “show processlist” command and decide to kill some processes if they violate specified rules. I have a prototype of one in python, and couldn’t find any other implementations until tonight when I came across Querybane, which is what Wikipedia use to do exactly the same thing.
Now, I need to think further about if querybane does what I want, especially given I can’t find the source code. Perhaps it’s hidden in the media wiki code somewhere? The only code for a project named “servmon” (it’s parent project) that I can find is four years old and in PHP.
(Oh, by the way, the Wikipedia MySQL docs are really interesting, for example this page has some nice practical advice about replication log corruption. I wish I had found this before now for two reasons: it’s nice to see how other people do this stuff; and there is some stuff I can totally steal from here.)
So, does anyone know where I can find recent querybane code? Alternatively, what do other people use as a query sniper? Is it worth open sourcing mine?
Update: Apparently what I needed to do was sleep on it, and use Google Code Search. The querybane code appears to be at http://svn.wikimedia.org/svnroot/mediawiki/trunk/servmon/. In the end it’s not going to work for me, as it seems to be really based around a world in which you use IRC to keep a track of the state of your servers, which isn’t something I want to do.