I was actually exploring inotify-tools for something else, but they can also be handy for seeing what goes on below a mysqld process. inotify hooks into the filesystem handlers, and sees which files are accessed. You can then set triggers, or just display a tally over a certain period.
It has been a standard Linux kernel module since 2.6.13 (2005, wow that’s a long time ago already) and can be used through calls or the inotify-tools (commandline). So with the instrumentation already in the kernel,
apt-get install inotify-tools is all you need to get started.
# inotifywatch -v -t 20 -r /var/lib/mysql/* /var/lib/mysql/zabbix/* Establishing watches... Setting up watch(es) on /var/lib/mysql/mysql/user.frm OK, /var/lib/mysql/mysql/user.frm is now being watched. [...] Total of 212 watches. Finished[Read more...]