This booklet is about one aspect of system and network monitoring: collecting, storing, reviewing, and acting on numbers (or, more formally, data points) that tell us something relevant about our environment. We are concentrating on instrumenting our systems and networks rather than on examining or monitoring the services we provide. We focus on monitoring our environment and less on controlling the equipment that controls it.
But with any monitoring process comes the ability to influence the thing being monitored, either automatically or through conscious action on the part of the person(s) doing the monitoring. As Lord Kelvin1 said, "If you cannot measure it, you cannot improve it," and we seek to improve our processes by monitoring what is going on in them."