Mainframe, Performance, Topics Podcast

By Marna Walle

Martin Packer (Principal z Systems Investigator) and Marna Walle (z/OS Development) are two IBMers talking about whatever z/OS topics come to mind. Often guest experts weigh in on current techno... more

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FAQs about Mainframe, Performance, Topics Podcast:

How many episodes does Mainframe, Performance, Topics Podcast have?

The podcast currently has 35 episodes available.

Mainframe, Performance, Topics Podcast episodes:

December 06, 2023Episode 34 "Homeward Bound"
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
...more
36min
July 05, 2023Episode 33 "These Boots Were Made"
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
...more
41min
April 21, 2023Episode 32 "Scott Free"
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
...more
42min
July 11, 2022Episode 31 "Take it to the Macs"
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
...more
45min
March 16, 2022Episode 30 "Choices Choices"
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
...more
36min
April 20, 2021Episode 29 "Hello Trello"
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.
...more
1h
March 02, 2021Episode 28 "The Preview That We Do Anew"
This episode is about several of the z/OS V2.5 new functions, which were recently announced, for both the Mainframe and Performance topics. Our Topics topic is on Martin's Open Source tool filterCSV. Full long show notes are here.
We have a guest for Performance: Nick Matsakis, z/OS Development, IBM Poughkeepsie.
Many of the enhancements you'll see in the z/OS V2.5 Preview were provided on earlier z/OS releases via Continuous Delivery PTFs. The APARs are provided in the announce.
If you use FTPS for your IBM software electonic delivery, a change is taking place on April 30, 2021. We strongly recommend you use HTTPS instead, but if you still want to use FTPS see IBM software electronic delivery change - take notice!
Mainframe - Selected z/OS V2.5 enhancements
IBM will have z/OS installable with z/OSMF, in a portable software instance format! z/OS V2.4 will not be installable with z/OSMF, and z/OS V2.4 driving system requirements remain the same. z/OS V2.5 will be installable via z/OSMF, so that is a big driving system change.

Learn z/OSMF Software Management at this website.

Notification of availability of TCP/IP extended services

Workload Manager (WLM) batch initiator management takes into account availability of zIIP capacity

Change the Master Catalog without IPL

IDCAMS DELETE mask takes TEST and EXCLUDE.

IDCAMS REPRO moves I/O buffers above line.

New RMF Concept for CF data gathering

RMF has been restructured, but all the functions are still intact. z/OS V2.5 RMF is still a priced feature.
Performance - zCX enhancements
zCX is important for co-locating Linux on Z containers with z/OS.

Popular use cases can be found here and in the Redbook here. Another helpful source is Ready for the Cloud with IBM zCX.

zIIP eligibility enhancements

New enhancements include support 1 MB and 2 GB large pages (still fixed) for backing guests.

Guest memory is planned to be configured up to 1 TB

Another relief is in Disk space limits

Monitor and log zCX resource usage of the root disk, guest memory, swap disk, and data disks in the servers job log.

zCX resource shortage z/OS alerts to improve monitoring and automated operations.

SIMD (or Vector). SIMD is a performance feature, and can be used for analytics.

Nick's presentation (with Mike Fitzpatrick) is here.
Topics - filterCSV and tree manipulation
Mindmapping leads to trees. Thinking of z/OS: Sysplex -> System -> Db2 -> Connected CICS leads to trees.

Has very little automation of its own. But crucially you can mangle the CSV file outside of iThoughts, which is what filterCSV does.
filterCSV is a python open source program that manipulates iThoughts CSV files, colouring CICS regions according to naming conventions

So it goes.
...more
50min
November 16, 2020Episode 27 "And Another Thing"
Episode 27 "And Another Thing" show notes. Long show note are here.
Follow up
Additional System Recovery Boost enhancements:
Sysplex partitioning recovery: Boosts all surviving systems in the sysplex as they recover and takes on additional workload following the planned or unplanned removal of a system from the sysplex.

Two more portable software instances: Db2 and IMS added to Shopz on Aug 20, 2020, in addition to CICS (Dec 2019).
ASK MPT
Martin was asked about which systems in a System Recovery Boost Speed Boost situation get their GCPs sped up to full speed.
Mainframe - Trying out Ansible for driving z/OSMF Workflows
Marna's been learning about Ansible and how it can drive z/OSMF work. So far with z/OSMF Workflows, from ansible-galaxy collection for ibm.ibmzoszosmf

Needed lots of assistance from two gracious Poughkeepsie system testers (massive thanks to Marcos Barbieri and Daniel Gisolfi !!)
Learning about an Ansible

Encountered two kinds of problems:

Security issues connecting the Linux environment to a large Poughkeepsie System Test z/OSMF environment

Workflow-related: duplicate instances when part of the playbook ran ok, and selecting an automated workflow.
Performance - So You Don't Think You're An Architect?
Brand new presentation for 2020, builds on the “who says what SMF is for?” slide in "How To Be A Better Performance Specialist"

Presentation talks about 3 layers

The Top Layer - Machines, Sysplexes And LPARs

The Middle Layer - Workloads And Middleware: Spikes, Restarts, Cloning, Topology, Software Levels

The Bottom Layer - Application Components: Db2 and MQ Accounting Trace, DDF topology, data sets

Fulfilling the definiton Of Architecture? Understand what's really going on and valuable to system architects
Topics - Notifications
They are unsolicited messages appearing on the device, generally interruptions whether wanted or not.

Examples of what is received and where/
IFTTT still a favorite of Marna's, mentioned in Episode 23 “The Preview That We Do” Topics topic. Martin just subscribed to Premium, but at a low-ball price.

How do you manage them to reduce their number.

An advanced topic is how you can generate your own

On iOS the Pushcut app: a webhook from eg IFTTT can cause a notification

On Android we have MacroDroid.
Customer requirements
Customer Requirement 138729 : z/OS Console message help support JES2 messages
IBM response: This RFE has been delivered via APAR PH24072 at end of June 2020. It's available on both V2R3 and V2R4. The JES2 message prefix such as $ can be setup in "Configure Message Help" dialog in z/OSMF Console UI.

On the blog
Martin's blog posts are here

Marna's blog posts are https://blog.share.org/Article/tag/marnas-musings
So it goes.
...more
57min
July 06, 2020Episode 26 "Sounding Board"
Here are the show notes for Episode 26 "Sounding Board". The show is called this because it relates to our Topics topic, and because we recorded the episode partly in the Pougkeepsie recording studio where Martin sounded zen, and partly at home.
What’s New
APAR PH21919: NEW FUNCTION - WORKFLOW SUPPORT SAVE JOB OUTPUT
PTF Numbers are UI68359 for 2.3 and UI68360 for 2.4

APAR OA56774 (since 2.2) Provides new function to prevent a runaway sysplex application from monopolizing a disproportionate share of CF resources
Not based on CF CPU consumption. Is based on deteriorating service times to other structures - which you could measure with SMF 74-4 Coupling Facility Activity data.

Mainframe - z15 FIXCATs
IBM.Device.Server.z15-8561.RequiredService: Absolute minimum needed to run on a z15. Usually intent is to keep these PTFs to a minimum - and keep the number of PTFs relatively constant. <>

IBM.Device.Server.z15-8561.Exploitation: Needed for optional functions, and you can decide when you want to use them. This PTF list could grow - if we add new functions

IBM.Device.Server.z15-8561.RecommendedService: Usually to fix a defect that is found but haven’t risen up to required. Might want to run an SMP/E REPORT MISSINGFIX to see what’s in this FIXCAT. Might install some, all, or none of the fixes. Might want to be more selective. Based on how much change you want to encounter, versus what problems are fixed

By the way there are other FIXCATs you might want to be interested in for z15, e.g. IBM.Function.SYSPLEXDataSharing
Performance - DFSORT And Large Memory
A very special guest joins us, Dave Betten, former DFSORT performance lead.

Dave talked about DFSORT memory controls
DFSORT has historically been an aggressive user of memory

Installation defaults can be used to control that

But the EXPOLD parameter needs special care - because of what constitutes "old pages", which aren't actually unused.

DFSORT Tuning Guide, especially Chapter 3

Dave talked about how handy rustling up RMF Overview Reports can be, with several Overview conditions related to memory.

Most of the information in this topic is relevant to LPARs of all sizes
Topics - Update on recording techniques
Recording of podcast - still using Skype to collaborate

Production - Editing - Moved to Ferrite on iPad OS

Publishing - same process as before, but on a new publisher!
Customer requirements (assume usual disclaimer)
RFE 139477 “Please include the CPU Time Limit for a Job/Step in SMF Type 30”
After the fact - End of step looks useful. Could run query comparing to actual CPU time, then track to see if ABEND is on the horizon

“ As it happens ” - Would like on the SMF Interval as well as Step End records. May not need the SMF information if vendor and IBM tools already do it today.
On the blog
Martin's has blog posts since the last episode.

Marna has three on her blog here.
So it goes...
...more
57min
March 22, 2020Episode 25 "Flit for Purpose"
Here are the show notes for Episode 25 “Flit for Purpose”. The show is called this because it relates to our Topic, and also can be related to our Mainframe topic (as a pun for “Fit for Purpose”).
Mainframe Topic: Highest highlights of z/OS V2.4 and z/OS on z15
Highlight 1: zCX

Highlight 2: z/OSMF
Lots of z/OSMF enhancements that have arrived in z/OS V2.4, and the good news is that most of them are rolled back to V2.3 in PTFs that have been arriving quarterly.

Security Configuration Assistant: A way within z/OSMF to validate your security configuration with graphic views, on the user and user group level. Designed to work with all three External Security Managers!

Available back to V2.3 with APAR PH15504 and additional group id enhancements in APAR PH17871

Diagnostic Assistant for z/OSMF : A much simplier way to gather the necessary information to need for a Service person to perform debug for your z/OSMF problem.
Hightlight 3: SRB on on z15: System Recovery Boost :Speeds up your shutdown for up to 30 minutes and speeds your re-IPL for 60 minutes, with no increase to your rolling four hour average.
Performance Topic: z15 from chip design on upwards
Disclaimer: personal view, not from Development or Marketing. Marna and Martin were talking about the z15 Chip design – and we thought those observations might be useful to include in the Performance topic.

Two traditional levers were raising clock speed or shrinking the feature size.

GHz and nm aren’t the be all and end all. Look at chip design.

Start with a similar sized CP chip and putting more on it. It helped to get rid of the Infiniband-related circuits, and some layout enhancements.

At the top end there are up to 190 characterisable cores, coming up from 170. This can give us a fifth drawer – which is quite important.
Topic: How To Do A Moonlight Flit
This topic is about moving one’s social output, in particular blogs and podcast series. Martin’s blog had to move, because the IBM developerWorks blog site is being shut down. Martin's blog has had to move, as well as this podcast.

Immediately people might worry about Request For Enhancements being affected , and it is not.

Martin and Marna discuss important aspects to consider when moving your social media.

You must consider all the pieces when do you the most.

You must also try to redirect your audience.
Contacting us
You can reach Marna on Twitter as mwalle and by email.
You can reach Martin on Twitter as martinpacker and by email and blogs at blog.
...more
42min

FAQs about Mainframe, Performance, Topics Podcast:

How many episodes does Mainframe, Performance, Topics Podcast have?

The podcast currently has 35 episodes available.