Category Archives: Uncategorized

(This post follows on from Engineering – Part Two – Non-Integer Weights Are A Thing, rather than Engineering – Part Three – Whack A zIIP). I was wondering why my HiperDispatch calculations weren’t working. As usual, I started with the assumption my code was broken. My code consists of two main parts: Code to buildContinue reading “Engineering – Part Four – Activating And Deactivating LPARs Causes HiperDispatch Adjustments”

A few years ago I built a presentation on zIIP Capacity Planning. It highlighted the need for better capacity planning for zIIPs and outlined precisely why zIIPs couldn’t be run as busy as general purpose processors (GCPs). Since then a lot has changed. And I, in common with most people, have a lot more experienceContinue reading “zIIP Capacity And Performance Presentation”

Every year I try to write one new presentation. Long ago, it feels like, I started on my “new for 2020” presentation. It’s the culmination-so-far 🙂 of my “architecture thing”. “What Architecture thing?” some of you might be asking. It’s quite a simple idea, really: It’s the notion that SMF records can be used forContinue reading “So You Don’t Think You’re An Architect?”

(I’m grateful to Dougie Lawson for correcting a few errors in the original version of this.) I don’t often write about IMS and there’s a good reason for it: Only a small proportion of the customers I deal with use it. I regard IMS as being one of those products where the customers that haveContinue reading “IMS Address Space Taxonomy”

There have been a number of WLM Service Definition formatters over the years. So why do we need another one? Well, maybe we don’t but this one is an open source one, covered by the MIT licence. That means you can change it: You could contribute to the project. You could modify it for yourContinue reading “sd2html, An Open Source WLM Service Definition Formatter”

I have a number of ideas for things I want to open source, some directly related to the day job and some not. This post is about one piece of software that I use in my day job but which you probably wouldn’t recognise as relevant to mainframe performance. To me the rule of thumbContinue reading “filterCSV, An Open Source Preprocessor For Mind Mapping Software”

If you want really good Db2 performance you follow the guidelines from Db2 experts. These guidelines contain such things as “ensure Db2 has excellent access to zIIP” and “put the Db2 address spaces up high in the WLM hierarchy”. Some of these rules come as a bit of a shock to some people, apparently. IfContinue reading “Is Db2 Greedy?”

I’ve been experimenting with invoking services on one machine from another. None of these machines have been mainframes. They’ve been iPads, iPhones, Macs and Raspberry Pis. I’ve used the plural but the only one actively dualed is iPhone. And that plays a part of the story. For the purpose of this post you can viewContinue reading “Let’s Play Master And Servant”

Ten years ago in Channel Performance Reporting I talked about how our channel-related reporting had evolved. That was back when the data model was simple: You could tell what channel types were and what attached to each channel: Field SMF73ACR in SMF Type 73 (RMF Channel Path Activity) told you the channel was, for example,Continue reading “My Generation?”

With z/OS 2.4 you can now run Docker containers in zCX address spaces. I won’t get into the whys and wherefores of Docker and zCX, except to say that it allows you to run many packages that are available on a wide range of platforms. This post, funnily enough, is about running Docker on aContinue reading “Dock It To Me”