Diagnosing performance degradation

You can save the metrics that the onperf utility displays, so you can analyze it and compare it to other saved information. This can be useful when analyzing performance problems that gradually develop and might be difficult to diagnose.

For example, if you detect a degradation in database server response time, it might not be obvious from looking at the current metrics which value is responsible for the slowdown. The performance degradation might also be sufficiently gradual that you cannot detect a change by observing the recent history of metric values. To allow for comparisons over longer intervals, onperf allows you to save metric values to a file, as explained in Status tool.