Author Archives: Martin Packer

(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”

(Originally posted 2014-09-08.) Some technologies show up “in the field” very soon after they’re announced and shipped. Others take a little longer. Back in 2009[1] I blogged about one technology – DFSORT JOINKEYS. For this post to make much sense you’ll probably want to read that post first. Here it is: DFSORT Does JOIN. DaveContinue reading “DFSORT JOINKEYS Instrumentation – A Practical Example”

(Originally posted 2014-08-18.) I’m pleased to be presenting three sessions at UK GSE Annual Conference, Tuesday 4th and Wednesday 5th November in Whittlebury Hall. Two are on the zCMPA (Performance and Capacity or “UKCMG”) track: Life and Times of an Address Space (Tuesday) zIIP Capacity Planning (Wednesday) I’ve written about these extensively. Obviously they’re evolvedContinue reading “Workload Manager And DB2 Presentation Abstract”