TSO Stats Under zOS 2.2

[Barry Merrill]

From: MXG Software LIST [mailto:MX...@PEACH.EASE.LSOFT.COM] On Behalf Of
Doug Medland
Sent: Friday, June 16, 2017 10:27 AM
To: MX...@PEACH.EASE.LSOFT.COM
Subject: [MXG-L] TSO Stats Under zOS 2.2



Good morning. All of our LPARs that have moved to zOS 2.2 have shown a
dramatic increase in the reporting of our TSO response time, especially P1.
In some cases, P1 was higher than both P2 and P3 response times. In other
intervals, TSO response was normal across all TSO periods. After digging
into what might be using our TSO service class I opened a PMR with IBM. I
had sent an email to some colleagues asking if they've seen this on their
zOS 2.2 systems. Someone pointed me to the MXG Newsletters (#67) and found
this:

z/OS 2.2 APAR PI69487 corrects the excessive response time for TSO
reported in RMF TYPE72GO elapsed time because each SDSF session's
elapsed time was included in the elapsed time of completed TSO
transactions.

Some detail from the APAR / PTF (associated with UI44842):

SDSF V2R2 offloads some work to a zIIP when a processor is
available. As part of this implementation, SDSF creates a WLM
enclave during initialization. Since the enclave is present,
TSO response time reports will show that SDSF is running as a
long transaction with associated high response times.

My IBM PMR came back with more questions so I had added the above comment(s)
to my inquiry. Closing date on this fix was 21FEB2017. IBM updated my PMR
with:

The PTF did not become available until April of this year.
It's part of RSU/1704. So you would have to be very current to have
this on. I'm glad your guy found this fix, we would have never looked
for a SDSF bug here.

As it turned out, this PTF was not applied to our system(s). TSO response
was actually fine but for sites with TSO SLAs this would hurt. I'm not an
SME on enclaves, and perhaps someone could help me here, but I'm guessing
enclaves running under TSO wouldn't use periods. This would explain why P1
was often higher than P2 or P3. Since the availability of this fix was only
a couple of months ago it might be a good idea to check if your sites have
this fix applied. We've already started scheduling this update on our zOS
2.2 LPARs.


Regards,

Doug Medland
IBM Global Services
SMI Performance & Capacity MF
Phone: (905) 316-1154


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