Mainframe Performance Topics Podcast Episode 8 “Queue Me Up”

(Originally posted 2016-10-29.)

We wanted to get this episode out much sooner, but things conspired against us somewhat. Not least someone we really wanted to interview – to kick off a whole series of topics – having technical troubles.

So we went a different way from what we intended.

And we also had a few scheduling problems. But we’re here now. I hope it was worth the wait.

And just to repeat one thing: If you come anywhere near use we’re miked up. 🙂 Seriously, we’re conducting impromptu interviews when we’re out and about. Find us or avoid us, to taste. 🙂

Below are the show notes.

The series is here.

Episode 8 is here.

Episode 8 “Queue Me Up” Show Notes

Here are the show notes for Episode 8 “Queue Me Up”. The show is called “Queue Me Up” because:

  • Marna talks about moving up to higher z/OS releases…or releases “in the queue”.

  • Martin talks about the Coupling Facility list structures…or “queues”.

We had some follow up:


Our “Mainframe” topic was a discussion on z/OS upgrade timing considerations.

z/OS R13 is now out of service since end of September 2016, five years of regular service support since GA. There are three consecutive releases of coexistence (with releases planned on coming out every two years).

This “discrepancy” between five years of service and and six years (three times two) of coexistence has been quite interesting and deserves some thought. Marna talks about some considerations, and it might be that the “n-2” model should be reconsidered to be a “n-1” model for some customers.


Our “Performance” topic was an extension of this blog post of Martin’s: Right On Queue.

Martin talks about Coupling Facility list structures, and how they are different from lock and cache structures. He also covers some considerations and causes for how they might get filled up. (Think of the analogy of a pipe getting blocked as one case.)

Sizing is important and he uses SMF 74-4 and RMF Monitor III. A good rule of thumb is that your structure’s maximum size should be in the range of 50% to 100% of the current size. More than double puts you at risk of having a list structure full of control blocks and little data. You also need to monitor how much of the current size is actually in use.


In our “Topics” section we discussed a travel app called Waze. It’s a crowd-sourcing app you can use to get real-time travel estimates and routes. It also alerts you about such items as accidents, debris, police cars, etc, which other users have reported. This app is particularly useful even if you have to put up with a very small amount of advertising.

Where We’ll Be

Martin is in the *shires (Buckinghamshire, Yorkshire, Wiltshire), as well as a short trip to Amsterdam, during the rest of the year (at the time of going to press). And…also with Marna in:

  • Guide SHARE Europe UK, November 1-2, 2016. A roving microphone might appear, so please join the conversation if you wish!

Marna is going to:

On The Blog

As well as Right On Queue, Martin posted to his blog since our last episode:

  • Automatic for the Peep-Hole – about experimenting with automation for his Apple watch to dictate and send emails – using both web-based and on-device tools. It was really a test bed for thinking about when on-device automation is best and when web-based automation is better.

  • Transaction Counts – about counting transactions with RMF.

Contacting Us

You can reach Marna on Twitter as mwalle and by email.

You can reach Martin on Twitter as martinpacker and by email.

Or you can leave a comment below.

Published by Martin Packer

I'm a mainframe performance guy and have been for the past 35 years. But I play with lots of other technologies as well.

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