Mainframe, Performance, Topics Podcast Marna Walle

Episode 34 "Homeward Bound"

Mainframe - z/OSMF Software Management UUID


What it is: ability to programmatically retrieve a unique value (UUID) which can then be used to find out installation information about the active z/OS system. This function is optional.
Requires: z/OS 3.1, an SMP/E CSI specific to that software instance, and an installed usermod which is provided by z/OSMF Software Management.
How it works: once the UUID has been encoded into your z/OS system's LPALIB data set, you can use a REST API to retrieve the UUID. Then, this allows you to use the UUID to run many other REST APIs to look at the installed software with assurance that you are looking at the actively running system software instance. You must ensure that for each new software instance, you install a new UUID. The UUID is also available from the D IPLINFO command.


Performance - Logical Processor Home Addresses


This is the LPAR's preferred physical location for a specific logical process to be dispatched. Drawer, DCM, chip, core. Degrees of meaning for Verical High, Medium, Low, and Dedicated.
z16 support is in the SMF 70-1 records, OA62064 . Better than SMF 99-14 in some ways.
Useful for an analysis of effect of PR/SM weights and HiperDispatch, verify location of ICF and IFL LPARs.
Logical processor is not always dispatched to its home address. VH and Dedicated will always dispatch to the home processor. Location of memory is not included, although SMF 113 gives hints.
Might need SMF 99-14 in addition, as it has affinity nodes, which 70-1 doesn't.
All in all, a very useful advancement in the instrumentation.


Topics - Useful Tips for Debugging a DFSORT E15 Exit


Martin explores his experiences with DFSORT E15 and offers advice.
DFSORT E15 is great at flattening records and enhancing filtering. You might find yourself needing to maintain this exit, which others have written.
Some useful advice is: let the exits do the I/O for you, do a COPY first, stop after one record at first, write diagnostic data into output records, forcing an abend can help, code a SYSUDUMP DD, maintain a DFSORT symbols convention, GETMAIN your working storage, and you can write to the spool.


On the blog


Marna's blog
Martin's blogs


So It Goes

Episode 33 "These Boots Were Made"

What’s New


Preliminary z/OS 3.1 Upgrade materials
Python 3.1.1 zIIP enablemment OA63406 and PH52983

Mainframe -


Requires: z/OS V2.5 with PTFs, IBM z16 with microcode. Has both driving and target system requirements, use IBM.Function.ValidatedBoot FIXCAT.
Front end: Siging the in-scope artifacts (NUCLEUS, LPA, IPL Text, and SA Dump Text), z16 is not required here although z/OS V2.5 and PTFs are.
Back end: Verification of those signed in-scope artifacts. z16 with correct microcode level is required here (with z/OS V2.5 and PTFs).
Security set up work is required.

Performance - Open Data Sets, Part 2


Follow on, from Part 1 which was physical open and close of data sets as seen by z/OS.
This is about Db2 with the notion of logically Open and Closed data sets.
Its main role is to manage inter-Db2 read/write interest, for Datasharing efficiency purposes.
Two Db2 subsystem parameters have traditionally been used to control pseudoclose: PCLOSET and PCLOSEN. PCLOSEN is gone in V12 with APAR PH28280, as part of a DSNZPARM simplification effort. So PCLOSET would need adjusting down to whatever mimics PCLOSEN - in anticipation of this APAR or V13.

Topics - Messing With Digital Electronics


Martin explores his experiences with input devices (Stream Decks, Quick Keys, ...)
Martin has even built his own input devices: having an RFID card kick off automation, rotary encoders, USB Human Interface Device.

On the blog


Marna's blog
Martin's blogs

So It Goes

Episode 32 "Scott Free"

What’s New


Preview of z/OS 3.1


Mainframe - SMFLIMxx Parmlib Member


IEFUSI exit replacement with a parmlib member, related to storage and limits that can be specified.
Functions are delivered as continuous delivery, such as the SAF check filter, and number of shared pages used.
In z/OS 3.1: Dedicated Real Memory Pools to assign memory to a specific application, like zCX, in all frame sizes.


Performance - Open Data Sets, Part 1


Looking at many open data sets (100s of thousands) for middleware.
ALLOCxx's SWBSTORAGE has to specify ATB to put control blocks above the bar. Applications need to exploit the service.
Monitoring virtual storage is key here, and remains important. The number of volumes needed affects how much memory is needed, so there is no one answer.


Topics - Evolution of a Graph


Martin explores the large improvements he's made with his custom graphing programs.
Start with naive rows and columns, with rigid labels.
Then, generating the titles with REXX. Then, using REXX to drive GDDM directly. Then, use REXX to generate many more data point and plotting them directly. Then, have REXX generate the series names.
Martin encourages all to evolve their graphs, to tell the story better, and run more efficiently.


Customer Requirement


ZOSI-2195 "Extended GDG causes space issues", has been satisfied. IGGCATxx's GDGLIMITMAX with OA62222 on V2.3.


On the blog


Marna's NEW blog location is here
Martin has quite a few new blog articles here


So It Goes

Episode 31 "Take it to the Macs" show notes.
This episode is about our After Show. (What is that?) Long show notes can be found here.

What’s New

New news for CustomPac removal date, it is July 10, 2022.
Data Set File System released OA62150 closed April 28th, 2022 only on z/OS V2.5

Mainframe - z/OS Management Services Catalogs: Importance of z/OSMF Workflows

z/OS Management Services Catalog, zMSC, allows you to customize a z/OSMF Workflow for your enterprise, and publish it in a catalog for others to "click and use".
There are 7 initial sample Services that IBM provides, or you can provide your own with a starting Workflow.
zMSC Services are based on z/OSMF Workflows. You can see why the discussion on knowing z/OSMF Workflows is important.

Performance - System Recovery Boost (SRB) Early Experiences

System Recovery Boost provides boosts of two kinds: speed and zIIP.
There are different capabilities of SRB, based on which HW server you are running (z15 or z16):Shutdown - which allows you to have 30 minutes worth of boosting during shutdown. This function must be requested to be used each time.
IPL - which allows you to have 60 minutes worth of boosting during IPL. This function, provided by default, is on.
Recovery Process Boost, provided on IBM z15. Extends to structure or connectivity recovery, for instance.
Newer additional functions for Recovery Process Boost, specifically on IBM z16, for stopping and starting certain middleware.

Martin has several early field experience, which he has summarised in four blog posts.

Topics - Stickiness

This topics explores what makes some technologies sticky, and some not.
Martin and Marna discuss some of the attributes are important for continuing to be used, and what makes a function fall away over time.Value
Completeness
Usability and immediacy
Reliability
Setup complexity


On the blog

Marna's blog is here
Martin has quite a few new blog articles here

So It Goes

Short show notes - long show notes here

We have a special guest joining us for the performance topic, Scott Ballentine.


What’s New


New news for CustomPac removal date, which has been extended past January 2022. The reason was to accommodate
the desired Data Set Merge capability in z/OSMF which customers needed. For the new withdrawl date, it is planned to be announced in 2Q2022.


Mainframe - Only in V2.5
This topic was looking at some new functions that are only in z/OS V2.5.


Data Set File System, planned to be available in 1Q 2022.
Dynamic Change Master Catalog
RACF data base encryption has a statement of direction.
Increase z/OS Memory limit above 4TB to 16TB.
More Concurrently ”Open” VSAM Linear Datasets. Db2 exploits with Apar PH09189, and APAR PH33238 is suggested.
ISPF Updates to ISPF in support of PDSE V2 member generations, and SUBMIT command to add an optional parameter SUBSYS.
Access Method Services - IDCAMS - DELETE MASK has two new options TEST and EXCLUDE
z/OS Encryption Readiness Technology zERT
There’s a lot of other stuff rolled back to V2.4


Performance - What's the Use? - with special guest Scott Ballentine
This discussion is a summary from a joint presentation on Usage Data and IFAUSAGE

The topic is motivational because customers can get a lot of value of out this usage data, and understand the provenance
of IFAUSAGE data.
A macro vendors or anybody use can use to show which products are used and how. It can show names: Product Vendor, Name, ID, Version, Qualifier,
Show numbers: Product TCB, Product SRB, FUNCTIONDATA
The data is ostensibly for SCRT, which is fed by SMF 70 and SMF 89
Scott talked about encoding via IFAUSAGE, appears in SMF 30 and 89-1
SMF 89-1: Software Levels query, Db2 / MQ subsystems query
SMF 30: Topology (e.g. CICS connecting to Db2 or MQ), Some numbers (Connections’ CPU)
Both SMF 30 and 89: FUNCTIONDATA
Examples were mentioned that might inspire developers to think about how they code IFAUSAGE
Hope is developers will delight customers by using IFAUSAGE right, and customers will take advantage in the way shown with reporting examples.


Topics - Choices, Choices
This topics is about how to choose a language to use for which purpose. Different languages were discussed for different needs.

Use Case: Serving HTML?
Host consideration: Running on e.g. laptop?
Host consideration: Running on z/OS?
Overall lesson: Choose the language that respects the problem at hand.


On the blog
Marna's blog is here

Martin has quite a few new blog articles here
So It Goes

This episode is about how to be a better z/OS installation specialist, z/OS capture ratios, and a discussion on using Trello. We have a special guest joining us for the performance topic, Miroslava Barahona Rossi.  Long show notes are found here .


Mainframe - Being a Better Installation Specialist



"Better" here means lessons learned, not competing with people. "Installation Specialist" might just as well have used "System Programmer" or another term.
There's definitely a reason to be optimistic about being a person that does that Installation Specialist or System Programmer type of work:
There will always be a need for someone to know how systems are put together, how they are configured, how they are upgraded, and how they are serviced...how to just get things to run.
Consider the new function adoption needs too. There are so many "new" functions that are just waiting to be used.
A really good installation specialist would take information they have and use it in different ways.
Knowing parmilb really well.
You can't be better by only doing things yourself, no one can know everything. You've got to work with others who are specialists in their own area.
Last but not least, learn how to teach yourself. Know where to find answers (and that doesn't mean asking people!). Learn how to try out something on a sandbox.




Performance - Capture Ratio




Our special guest is Miroslava Barahona Rossi, a technical expert who works with large Brasilian customers.
Capture Ratio - a ratio of workload CPU to system-level CPU as a percentage.
Commercial considerations when billing for uncaptured cycles. You might worry something is wrong if the capture ratio is low.
Reasonable value is usually 80 - 90. Seeing more like 85 - 95 these days. It has been improved because more of I/O-related CPU is captured.
Summary:
Don’t be upset if you get a capture ratio substantially lower than 100%. That's normal.
Understand your normal. Be aware of the relationship of your normal to everybody else’s. But, be careful when making that comparison as it is very workload dependent.
Understand your data and causes. See if you can find a way of improving it. Keep track of the capture ratio over the months and years.



Topics - Hello Trello



Trello is based on the Kanban idea.
Why are we talking about Trello?  We moved to it for high level podcast planning.  Template used for hatching new future episodes. We move cards around sometimes between episodes.
Marna uses it to organise daily work, with personal workload management and calendaring. But it is not a meetings calendar.
Probably with Jira will be more useful than ever. We'll see.
Martin uses it for team engagements, with four lists: Potential, Active, Dormant, Completed. Engagement moves between lists as it progresses




Martin's blog
Marna's blog


So It Goes.