I have two mysql boxes setup. Fast machines, I think they are dual 3ghz with boat loads
of ram. They are not real busy servers but they have some pretty good sized tables, one
of them with a few million rows.
My question is, I have Nagios setup to monitor the seconds behind master on the backup
server. Usually the boxes are pretty current, within ten or twenty seconds. Other times
though they seem to get way behind, like I just bumped the nagios warning email level up
to 600 seconds. It doesn't seem to have anything to do really with usage because it
usually happens in the middle of the night. Does Mysql do re-indexing or something?
What could I do to figure out why the replicatant box is getting so far behind?