A Slice Of PI

(Originally posted 2019-06-01.) A rather obscure pun, but I hope it’ll make sense. Not “Pi” by the way but “PI”. Though this post contains arithmetic, it’s not a mathematics post. To be honest, I never knew how we calculated Performance Index (or PI) for Percentile goals before. But now I do, so I’m sharing itContinue reading “A Slice Of PI”

What’s In A Name? – Revisited Again

(Originally posted 2019-05-27.) It seems to be in the nature of my code development work that I revisit things over and over again. You could call it “agile”, you could call it “fragile”. 🙂 I prefer to think of it as being inspired by each fresh set of customer data. And so it is withContinue reading “What’s In A Name? – Revisited Again”

Engineering – Part Two – Non-Integer Weights Are A Thing

(Originally posted 2019-05-26.) Maybe you’ve never thought much about this but aren’t weights supposed to be integer? Well, they are at the LPAR level. But what about at the engine level? Let me take you through a recent customer example. The names are changed but the numbers are real, as the one graphic in thisContinue reading “Engineering – Part Two – Non-Integer Weights Are A Thing”

Engineering – Part One – A Happy Medium?

(Originally posted 2019-05-25.) In Engineering – Part Zero I talked about the presentation that Anna Shugol and I have put together. That post described the general sweep of what we’re doing. This post, however, is more specific. It’s about Vertical Medium logical processors. To keep it (relatively) simple I’m describing a single processor pool. ForContinue reading “Engineering – Part One – A Happy Medium?”

Engineering – Part Zero

(Originally posted 2019-03-22.) I’m writing this on a plane, heading to Copenhagen. Planes, like weekends, give me time to think. Or something. 🙂 Ardent followers of this blog will probably wonder why there have been few “original content” posts to this blog1 recently. Well, I’ve been working on an exciting project with my friend andContinue reading “Engineering – Part Zero”

Mainframe Performance Topics Podcast Episode 23 “The Preview That We Do”

(Originally posted 2019-02-27.) This episode is hot on the heels of the previous one. Marna set us the ambitious goal of getting it out on the day of the Preview Announcement of z/OS 2.4 – February 26th. And we succeeded. Phew! I’m really excited about the Docker / Container Extensions (zCX) line item and I’mContinue reading “Mainframe Performance Topics Podcast Episode 23 “The Preview That We Do””

Mainframe Performance Topics Podcast Episode 22 “Great App-spectations”

(Originally posted 2019-02-20.) We just posted Episode 22 of Mainframe, Performance, Topics. It features two of the longest topics we’ve ever recorded – and we think both of these topics warrant the time. If you want to fit this into your daily commute feel free to drive round the block a few times. 🙂 TheContinue reading “Mainframe Performance Topics Podcast Episode 22 “Great App-spectations””

Return Of Paging Subsystem Design

(Originally posted 2019-01-14.) In Paging Subsystem Design, in 2005, I opened with the words "Periodically on IBM-MAIN I’m caused to revisit something. With the advent of z990/z890 and “supposedly abundant” 🙂 real memory it seems to be time to revisit paging subsystem design.” Note the smiley is in the original. Seems funnier now. The z990/z890Continue reading “Return Of Paging Subsystem Design”

Anatomy Of A Great iOS App

(Originally posted 2019-01-06.) This post isn’t about what a great iOS app would functionally do. It’s about what would turn a useful app into a great one. There are obvious personal biases here: Automation is important to me. I have most of the Apple ecosystem – but no HomePod speakers (yet). I really want goodContinue reading “Anatomy Of A Great iOS App”

Automation On Tap

(Originally posted 2019-01-01.) While some beer was tasted over the vacation period, this post is about a different kind of tap. During my Xmas and New Year holiday I’ve been experimenting with ways of kicking off automation that don’t involve talking to a device, or tapping on it, or typing anything. Specifically what you canContinue reading “Automation On Tap”