Author Archives: Martin Packer

(Originally posted 2013-03-29.) As you will’ve seen in WLM Response Time Distribution Reporting With RMF I’ve been thinking about WLM Response Time goals quite a bit recently. And this post continues the train of thought. It’s very easy to think of WLM Service Classes as being self contained. For many that’s true – and onlyContinue reading “Are You Being Served?”

(Originally posted 2013-03-20.) If you’re running a workload with WLM Percentile Response Time goals take a look at the RMF Service Class Period Response Time Goal Attainment instrumentation. It’s in the Workload Activity Report but this post is about using the raw data to tell the story better than a single snapshot (or long-term “munging”)Continue reading “WLM Response Time Distribution Reporting With RMF”

(Originally posted 2013-03-18.) First, I’m indebted to Ray Mullins for his help in figuring out how to solve the problems I identified as remaining in Alternate Macro Libraries: A Way To Document Assembler Tables. Indeed he wrote a very handy blog post of his own: Wrapping your own macro code around vendor-supplied macros without changingContinue reading “Alternate Macro Libraries – Part 2”

(Originally posted 2013-03-16.) It’s hard to write about test environments without feeling you’re insulting somebody. That’s certainly true when it comes to performance tests. But I think that very fact is indicative of something: It’s incredibly difficult to get it right. Put another way, most environments are compromises. In recent weeks I’ve seen a numberContinue reading “Testing Is Trying”

(Originally posted 2013-03-14.) Suppose you have a set of numbers S over which you define a function f. Further suppose you partition S into S1 and S2. I’d like to know what function g is such that g({f(S1),f(S2)}) = f(S). As much to the point I’d like to understand which functions f even have aContinue reading “Cloning Fan-In”

(Originally posted 2013-03-12.) I’m sharing this technique in case it’s useful to you. And, selfishly, in case you can think of refinements. 🙂 (I’m not the best assembler programmer in the world so could easily be missing a trick or two.) We map SMF records using a set of assembler macros – to create whatContinue reading “Alternate Macro Libraries: A Way To Document Assembler Tables”

(Originally posted 2013-02-24.) Another week, another app. This time it’s a game – and therefore a good excuse to (perhaps gratuitously) try out the iPhone’s screenshot capability. (In case you don’t know, you press the power button and the home button simultaneously. If you do you get a nice camera-like click and the screenshot goesContinue reading “Appening 2 – Broken Sword Director’s Cut on iOS”

(Originally posted 2013-02-23.) When I first heard of Flash Express as part of the zEC12 announcement – some time before announcement – I thought of one use case above all, and one of particularly poignant resonance with some of my readers: Dump capture amelioration. Then, in the marketing materials, I heard of others. And theContinue reading “Flash Saviour Of The Universe?”

(Originally posted 2013-02-17.) I’ve added the words “on iOS” because this might spread to other platforms. A week ago I posted that I’d pick an app a week and try to get value out of it. I also said I might blog about what I think. This week’s app is Note & Share – anContinue reading “Appening 1 – Note & Share on iOS”

(Originally posted 2013-02-15.) A couple of things have happened recently that lead me to post about projecting the amount of CPU that’s zIIP eligible. (Everything in this post applies equally to zAAPs, of course.) When we first introduced z/OS specialty engines we introduced the “Project CPU” mechanism, reporting most notably via RMF. (I emphasise “z/OS”Continue reading “zIIP Eligibility When You Don’t Have A zIIP”