If only your database would just tell you that replication had failed or that the disk was full…
Ok some database servers do but MySQL doesn’t (yet). Another excuse to write a script

In my pursuit for total database visibility I have been searching for a tool that would tell me when something went wrong, that would simulate regular usage, and let me know if anything failed. After all SNMP can only probe so far and if your database is secure the last thing you want to do is open up another port on your server.

Don’t get me wrong there are tools out there that do a decent job of monitoring MySQL. MySQL Entperprise Monitor is one such tool. But if you want to look under the hood or add some functionality specific to your environment things start to get tricky.

So what’s this dbAlerter?

dbAlerter is the name of a project (Script) that I started developing to provide notification of key server events. It’s written in Python; Why?, I wanted something lightweight. Java would have been my first choice but the JVM eats too much ram and felt too heavy for such simple functionality.
Python on the other hand feels lighter and when running a script as a daemon it seems to take up less resources allowing the DB to use more memory and continue doing it’s job. Plus it’s been a while since I wrote anything with Python, variety is the spice of life!

Speaking of Java, if you have ever used tools like JConsole and jmap (and if not why not!) you may not have realised that since JDK 6 Update 7 there’s now one tool to rule them all - VisualVM.

VisualVM pulls together several commandline tools like JConsole, jstat, jinfo, jstack, and jmap to make monitoring and profiling a more visual experience.

Now that the changes from BSD Java have been merged into the OpenJDK and the FreeBSD Foundation have updated the JDK to 1.6.0-7 I’m pretty sure the original concept of write once run anywhere is closer than ever.