John Brady's Weblog

Monday July 04, 2005

Performance Monitoring – Measuring Activity

I'm a big believer in proactive performance management, which means lots of different things. One aspect of it is doing proper performance monitoring of your systems.

Performance monitoring a system really means measuring and recording what is happening on that system. In simple terms – if you don't measure it, how can you know what is going on? If you don't know what is happening on each of your systems, how are you ever going to be able to diagnose the real cause of a performance problem?

And if you don't record it somewhere, how can you do any kind of analysis on the data being gathered? You need to have reliable data on what the system was doing, both recently and in the past.

Reliability is both about recording the data and measuring it accurately. You need to record the data so that you are looking at a consistent set of related values, rather than a set of constantly changing values. Accuracy is important, as inaccurate data will not help you identify the real cause of any performance problem, and so help with finding a solution. You need to be able to trust the performance data being gathered about your system.

However, it is not enough to know that CPU utilisation has risen to 80%. You also need to know what is consuming those CPU cycles. Only then can you focus in on the culprit(s), and try to find out what they are doing.

So performance monitoring needs to collect data from a system perspective (a collection of resources) and a workload perspective (a collection of processes), to get both sides of the system activity equation:

• how busy are the system resources? i.e. what are they doing?
• what is using the system resources? i.e. what is each process up to?

( Jul 04 2005, 12:07:29 PM BST ) Permalink Comments [0]