$Id: README.hints 1.1 Sat, 26 Aug 2000 15:22:34 -0400 trockij $
To be sure that mon works reliably, you may want to pay attention to the
-Keep all alert and mon directories on a local filesystem. When
the daemon is run, be sure that PATH does not contain remote
-Do your best to make the mon host maintain independence of all systems
that it is monitoring. Configurations may vary as different services
are being monitored. For example, if you need to monitor whether
DNS is operational, don't depend on DNS being available in the monitor
script. Use a local hosts table which contains all the hosts referred
to in the configuration file.
-If you're monitoring a network resource, don't depend on using the network
to deliver alerts. If you subscribe to a paging service,
get "Quick Page" or "tpage", and hook a modem and phone line up to
the host which runs the daemon.
-Be aware of dependencies on services so that you're not surprised
when one component fails, and then see that three more things fail
because of this. If you get burnt by this situation, learn from it and
see what you can do minimize the dependencies.
-Remember the power of "m4" if you want to do more complex things with
the configuration file.
To be sure that mon works efficiently, respect these rules:
-Monitor programs should parallelize, like fping does. Instead of
doing a bunch of fork(2)s to send out a lot of pings, it does
it all from a single process, using nonblocking I/O, like Dan Farmer's
"fping" from the Satan package.
-If you use hostnames in your hostgroups, consider keeping a local
/etc/hosts file on the mon server. Monitors can generate lots of DNS