3/7/08 How to quickly find jobs using high CPU

When a system is performing poorly, in terms of response time, here’s something that can help find the culprit:

WRKACTJOB

From the display, move the cursor to the CPU column heading and use F16 to sort the jobs by that column. From there, it is easy to determine which jobs are consuming system resources (and how much) at that point in time.

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3 comments:

Paul Weyer said...

This can also be done by specifying the sequence parameter on the WRKACTJOB command as follows

WRKACTJOB SEQ(*CPUPCT)

Captain Ron said...

or use WRKSYSACT if installed. WRKACTJOB does not show it corect. If you add up all the CPU it does not = 100%. Weird

Vision Solutions said...

WRKACTJOB shows the percentage of CPU used over the elapsed time interval.

The cumulative percentages will be less than 100% if there is not enough demand by the currently running jobs to use 100% of the processing capabilities of the assigned processors.

Similarly, for uncapped partitions that are configured to use shared processors, the CPU percentage may exceed 100% if there is enough demand by the currently running jobs to use more than the assigned processing capacity and there are processors in the shared processor pool that are available to be used to handle the excessive demand on that partition.