Its difficult to tell from a distance what the problem is.
I suggest you get a good capacity performance person to take a look.
Someone with experience should be able to help you out as there are
so many variables.
He should be able to do it remotely if that is an issue.
Ed
On Sep 18, 2014, at 8:52 PM, Meenakshi, Vinoth - CW wrote:
Thanks Allan, Koehler &Engelbrecht.
We are using z/OS 1.13 and we already pulled the RMF report and
many of jobs are long running and for sample I have list couple of
them.
During the Batch window only its rising to 100% and remaining time
its normal. We made analysis on STS's, Network, Tape, TSO & Jobs
and only the Batch job is making to reach high CPU %.
Regards,
Vinoth M
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-
[email protected]] On Behalf Of Staller, Allan
Sent: Thursday, September 18, 2014 6:27 PM
To: [email protected]
Subject: Re: High CPU Utilized
High CPU utilization is not (by itself) a problem. OS/MVT (and all
of its successors, OS/MVS, MVS/ESA, OS/390. z/OS..) have been
designed (and redesigned) to run at 100% utilization for months and
years at a time (I know, I have been there).
That being said, most things will run (FSVO) better when there is a
little excess capacity.
There are so many variables that can contribute to elapsed time
that I can't even begin to provide any sort of meaningful
discussion about any of them.
A partial list of things to look at:
PR/SM overhead (too many logical processors defined) Workload
manager policy Device contention DFHSM (or equivalent) recall
Virtual Tape recall Human factors (physical tape mounting) Job
Scheduling Job Contention And many more...
One key to look at is the RMF Mon I CPU report. The key number is
the "IN READY" queue.
The ideal number is (number of logical processors * 1). That is,
one job is always ready to execute.
IN READY < 1 indicates excess CPU capacity IN READY > 1 indicates
excessive workload (FSVO excessive). There is no Rule of Thumb
here. Whatever you can tolerate is a good number
As other have said, are SLA's being missed?
HTH,
<snip>
In environment we are using 2818-X02 box with around 1100 MIPS and
this boxes is utilized by couple of LPARS(SYSP & SYST). One is a
PROD and other is Play LPAR and almost 90% of weight is contributed
to PROD SYSP system.
We have a scenario of High CPU utilized only during our batch window
(4hours) and few days back the system was recycled due to the high
CPU utilized and we feel that this may create impact during Peak
season in November, December.
Also we got a report from our batch team and most of batch jobs
are using more CPU time with very high elapsed time and below is
for your ref.
JOB NAME CPU TIME ELAPSED TIME
Job A 29:22.1 01.48.26.24
Job B 19:12.3 02.44.26.24
We are position to bring down the CPU Utilization time and make the
system healthy and we are trying to split the Batch jobs and run on
different time.
I would like to get some clarity on the Elapsed time, whether this
elapsed will make use of the CPU and will it be the cause of high
CPU utilized during batch window?
</snip>
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