Previously I took readers over the merits of Nagios, the Open Source
system monitoring tool. For some people Nagios is too heavy and
requires far too much time and effort to configure; what's needed is a
lightweight monitoring tool which can keep an eye on daemons and let you
know when things aren't as they should be. 'monit'
(http://www.tildeslash.com/monit/) seems to fit the bill, it could also
make a useful companion to Nagios as it will detect a dead process and
restart it for you! A handy HTTP interface is built in so you can check
on the system status from the comfort of a web browser. Services can be
put in to groups for easy management, dependencies can be configured
between services and files/disks can be monitored.
All over this looks
like a useful little program (compiles to 200KB), I haven't tried it yet
but intend to in the near future—maybe you can give it a try and let us
know how you got on?