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z Systems Technical University, Dublin 18-22 May 2015, Slides
As most people know, I thoroughly enjoy conferences and learn a lot.
The Dublin one 18 - 22 May was no exception. It was great to meet up with old friends, connect with potential new ones and have a couple of compromising photos of myself and friends to prove it. But you probably don’t care much about that - unless you’re in those photos. So here are the slides from the three... [More]
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The Unfit Bit? :-)
I’ve put off writing this post for a while.
Largely because it might sound like boasting.
The truth being I have very little to boast about. But here goes anyway. I’m a fitful [1] exerciser.
It’s not that it’s painful but that it’s not interesting.
I’ve never found a sport I enjoyed watching nor partaking in. But with that characteristic it’s been a... [More]
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Sysplexes Sharing Links
Just a brief one this time.
A customer recently asked me how to detect Sysplexes sharing Infiniband links. [1] It arose when discussing the information in the new(ish) Channel Path Data Section in RMF’s SMF 74 Subtype 4 record. The question really boils down to “how do I detect in RMF / SMF different Sysplexes using the same identifiable link”?
[2] My first suggestion was the... [More]
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Remember The Milk: Automatic For The People?
This post is one where I really don’t speak for IBM. [1] It’s also one that’s firmly in the “Topics” category of “Mainframe, Performance, Topics”, [2] being about the emergent fields of iOS Automation (and Web Automation). And, while I give Remember The Milk a “could try harder” score I’m actually a big fan of what they do.
Like many... [More]
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Restructuring
Being about Coupling Facility structures, maybe this should be called “re Structuring”. Standing on the shoulders of giants, as I do , it is with some temerity that I rethink one of their designs.
And it’s only because you might find it helpful that I mention it now. Since the dawn of time coupling facilities have contained four kinds of structures: Lock Cache List Serialized... [More]
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Commatosis
Regular readers of this post will have noticed the masthead
[1] changing. I thought it appropriate to replace the zEC12 (and zBX) graphic with the new z13.
I’ve also taken the opportunity to weave in a little gag.
The blog’s title remains “Mainframe Performance Topics” but you’ll see I’ve injected a couple of commas in the masthead. These commas make all the... [More]
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False Contention Isn't A Matter Of Life And Death
It’s more like someone rich lighting their cigar with a hundred dollar bill. Seriously, this post is about Coupling Facility Lock Structure False Contention and why it matters.
It is, of course, inspired by a recent customer situation. Before I explain what False Contention is, and then go on to talk about its impact and instrumentation, let me justify the title by asserting
Lock... [More]
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And Now In Colour
As you know, we turn data into reports and try to make sense of it.
One thing we’ve not done before is use colour in our textual and tabular reports.
So here’s what I’ve learnt about how to make B2H use colour.
Our Reporting Process But first a word or two about how we get these reports. We collect SMF data into engagement-specific VSAM-based performance databases. We use... [More]
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What's The Latency, Kenneth?
OA37826 really is the gift that keeps on giving: I got really nosy about Coupling Facility links when it came out [1] , though most customers didn’t get the added benefits of CFLEVEL 18 for a while. This post is about a customer installation which pointed out another benefit of the instrumentation.
[2] Customer Example I’ve simplified the customer situation a little - in a way that... [More]
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As Alike As Two Peas In A Pod
… or probably more. I was going to use “Send In The Clones” but I’ve already used it - and someone who shall remain nameless once misremembered it as “Let There Be Clones”. Let there be clones, indeed. So, how do I detect cloned CICS regions, for example? (And if you want to know why I’m asking that question now it’s an enforced rereading of
CICS... [More]
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CICS XCF Traffic Analysis - A Suitable Case For Treatment
In He Picks On CICS I mentioned XCF traffic and CICS. This post is about a customer situation where looking at this traffic was important. Often I’m looking for topology (maybe “tourist information” to some of you). This time I have another motivation: Performance. In this customer saving z/OS CPU is important. [1] I’ve noticed that the Coupling Facility CPU has XCF... [More]
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Proposed "DB2 Through My Eyes" Presentation
I have a new conference presentation in mind.
Its working title is “DB2 Through My Eyes”.
Here’s the structure I’ve devised for it: Abstract What Is DB2? CPU
General Purpose zIIP Memory
Real Virtual I/O
Database Subsystem Application
Connections Performance Parallel Sysplex
Coupling Facility XCF Specialist Subjects
Restarts Workload Manager Stored... [More]
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Some WLM Questions
As I’m working with a couple of colleagues on a performance study I thought I’d list some “starter set” questions I’d ask about any customer’s WLM policy. [1] Before you go too far with this post you might like to read
Analysing A WLM Policy - Part 1 and
Analysing A WLM Policy - Part 2 but I don’t think I’m repeating myself much here. So here are... [More]
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I'm Surprised Nobody's Complained :-)
It’s a little surprising to me that nobody complained about one aspect of the behaviour in the code in
GreaseMonkey Script To Sum Selected Numbers In A Web Page .
I’ve been muttering under my breath and I wrote the code. This code naively assumes that in every web page there is just one body element.
It is rather naive, and I’ve known that for a long time. What really... [More]
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GreaseMonkey Script To Sum Selected Numbers In A Web Page
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 up some numbers you see there.
Perhaps they’re in a column in that table. With this script you select the numbers... [More]
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The Effect Of CF Structure Distance
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, 3 kilometers apart, with an ICF in each machine and Parallel Sysplex members in each... [More]
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After An Indecent Interval
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.
But I think - quite apart from the interest - it has some usefulness in... [More]
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What's The Point Of WLM?
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 Wilkins for the photograph.) So let me try to give you a synopsis of my view, expanding on each of the... [More]
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Not So Much Renaissance Man More Tool-Using Ape :-)
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 About Web Technologies To try and keep this focused I’m going to talk only about why web... [More]
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The End Is Nigh For CICS
… 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 you can estimate when address spaces stop from the SMF 30 Interval records (Subtypes 2 and 3): When there is... [More]
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Curiouser And Curiouser, Spike
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 way it’s similar to what restarts tell us, hence the above blog post link. I like “Think... [More]
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WLM Velocity - Another Fine Rhetorical Device I've Gotten Myself Into
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 right decision. But in the presentation I mention here: Workload Manager And DB2 Presentation... [More]
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DFSORT JOINKEYS Instrumentation - A Practical Example
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 . Dave Betten and I have - at last - a set of data from a customer where one of the... [More]
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Workload Manager And DB2 Presentation Abstract
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 evolved a bit and I have specific... [More]
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Broker And SMF 30
Sitting in Dave Gorman’s Broker V9 presentation in Budapest it struck me it would be a useful exercise to apply the “Systems Investigation” techniques I write about to Broker running on z/OS. So let’s see how far we can get with SMF 30 Interval records, in the vein of Life And Times Of An Address Space . It’s a nice exercise [1] but I think it’s directly useful... [More]
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System z Technical University, Budapest 12-16 May 2014, Slides
In Budapest at the European System z Technical University I presented three topics: zIIP Capacity Planning (twice) Life And Times Of An Address Space Parallel Batch Performance Considerations The links take you to the Slideshare uploads of these presentations. The first two of these are updated for this conference and I’ve overwritten the previous versions - as the new versions subtracting... [More]
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And Just Complain
“Mobile” appears to be “flavour of the month” right now, and this week at System z Technical University it has certainly been a topic in evidence, whether it’s discussions in the breaks, sessions on software pricing, or sessions on Mobile-enabling technology. I don’t intend in this post to discuss any of these. Instead I want to talk about the types of users... [More]
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Hints Of Other Systems
You can blame the weather for this post. I’m writing it on a flight above thick cloud [1] on my way to Munich and then to Budapest for this year’s European System z Technical University. I like to see the complete picture when I’m examining systems:
It makes getting it right so much easier.
And there’s something rather satisfying about getting your arms all the way round... [More]
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Appening 4 - SwiftKey on iOS
Sometimes I’m in the mood to carefully peck at the text and sometimes I’m in the mood to just “splurge write”.
And sometimes a bit of both. This post is a case in point:
I just want to get the words out as fast as I can. Now, I do quite a bit of writing on iOS as it lets me write wherever and whenever I get the chance.
I like its prediction and correction... [More]
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Once Upon A Restart
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If you have a large mainframe estate it can be difficult to keep track of when the various moving parts start and stop.
For example, if you’re a Performance person it’s quite likely nobody bothered to tell you when the systems were IPL’ed.
You might well know what the regime for starting and stopping CICS is but I... [More]
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