Author Archives: Martin Packer

(Originally posted 2014-12-13.) This post is meant to inspire people who like programming the web to do simple tasks. It contains a sample Firefox GreaseMonkey [1] script, which I hope you will find useful. [2] Suppose you are looking at a web page, perhaps one with a table in, and you want to add upContinue reading “GreaseMonkey Script To Sum Selected Numbers In A Web Page”

(Originally posted 2014-12-07.) I thought I’d write about how I begin looking at virtual storage, occasioned by a customer who had a 24-bit virtual storage (878–10) ABEND[1] . Most of this is in our code, so easy for me to do. I hope you’ll find it similarly easy. You’ve had hints of this in HowContinue reading “How I Look At Virtual Storage”

(Originally posted 2014-11-29.) Here’s an interesting case that illustrates the effect of distance between a z/OS image and a Coupling Facility structure. I don’t think this will embarrass the customer; It’s not untypical of what I see. If anything I’m the one that should be slightly embarrassed, as you’ll see… A customer has two machines,Continue reading “The Effect Of CF Structure Distance”

(Originally posted 2014-11-23.) Or “who made all the pies”? 🙂 I’ve written a number of times about Coupling Facility Performance but I don’t think I’ve written about memory for a while. In any case I’d like to share with you a couple of graphs I’ve taught my code to make. The first isn’t strictly speakingContinue reading “Coupling Facility Memory”

(Originally posted 2014-11-16.) In After A Decent Interval I talked about the need for frequently-cut SMF Interval records. This post is about bad behaviours (or maybe not so bad, depending on your point of view). It’s actually an exploration of when interval-related records get cut, which turned into a bit of a “Think Friday” experiment.Continue reading “After An Indecent Interval”

(Originally posted 2014-11-09.) At UK GSE Annual Conference I presented on DB2 and Workload Manager. It occurred to me that one of the slides was a good basis for a blog post, posing the question “what’s the point of WLM?” And this was the slide, with me “for scale purposes”. 🙂 (Thanks to Karen WilkinsContinue reading “What’s The Point Of WLM?”

(Originally posted 2014-11-02.) If you come to my blog only for Performance- or SMF-related topics you’re going to be disappointed in this post. But if, like me, you’re interested in storytelling and web-related technologies then read on. This post is about HTML5 Canvas – a technology I really like. Some Of Why I Care AboutContinue reading “Not So Much Renaissance Man More Tool-Using Ape :-)”

(Originally posted 2014-10-12.) … and other address spaces, too. 🙂 In Once Upon A Restart I talked about how to detect IPLs and restarts of CICS regions and MQ subsystems (and other long-running address spaces) – from SMF Type 30 Interval records. It’s easy to see starts but what about stops?[1] It turns out youContinue reading “The End Is Nigh For CICS”

(Originally posted 2014-09-28.) As you’ve probably gathered I like to get nosy about how customers run systems. This is probably best and most recently exemplified by this blog post: Once Upon A Restart So this post is about another piece of curiosity: What spikes can tell us about how people run systems. In a wayContinue reading “Curiouser And Curiouser, Spike”

(Originally posted 2014-09-21.) Back in 2010 I wrote about a graph I’d developed for understanding how a Service Class Period’s velocity behaves. That post is here: WLM Velocity – “Rhetorical Devices Are Us”. At the time I was concerned not to show up the customer by displaying the graph. I think that was the rightContinue reading “WLM Velocity – Another Fine Rhetorical Device I’ve Gotten Myself Into”