We run pretty much all of our big brother tests every minute. On
our new hobbit servers, we're running them at the default intervals.
BB shows us that our primary name server is going out for less than
a minute, about every 62 minutes.
Hobbit is missing most of those
outages, although the longer "xxxx events received in the last xxx
minutes" is what helped us spot the problem, as a whole bunch of
machines' services don't respond well when our primary name server
is out, and having a mass of servers go yellow then green, in
unison, is sort of eye catching.
So hobbit with the xxx events (running every 5m) did provide enough information to indicate an intermittent problem with DNS?
Things running every 5m will collide with a problem that happens for a minute frequently enough to 'show up on the radar'
But every site has different requirements. It's just been my experience that sampling more frequently than 5m hits the knee-bend of diminishing returns. It also increases the potential for state changes, which chews up the filesystem with the history info.
ymmv
scott