"Monitoring and analyzing masses of information--Is the CPU overloaded? Is the network interface saturated?--across several hosts is a daunting task. A good solution might be only a few steps away, though! The open source Nagios project (see Resources) solves complex monitoring and notification requirements quite handily.
"Crucial to understanding Nagios is that, rather than monitor and track 'natural' measurements such as CPU utilization, the tool reduces all information to 'working,' 'questionable,' and 'failure' states. This helps operators focus on the most important and crucial problems, based on predefined and configurable criteria..."
