95
All posts
Going Global
In the interstices between finishing off a "rush job" piece of analysis for ONE customer and a conference call with a vendor on behalf of ANOTHER it's time to catch up with a piece of news... As some of you will know I have a new job in IBM... I've joined Software Group's Worldwide Banking Center of Excellence (WWCoE for short) as their z/OS System Performance person. So, it's a pretty... [More]
|
If The Cap Doesn't Fit...
... swear at it. :-) No, I KNOW that's not right - but it's (for me) an irresistibly bad pun. And it's a natural reaction, too. :-) In a recent customer situation I looked at the RMF Workload Activity Report data for a number of service classes. One WLM Sample count was particularly high: "Capped". In fact I look at, with tooling, SMF and the actual field is R723CCCA. (An IBM... [More]
|
What I Did On My Vacation
First of all, a happy and prosperous 2010 to one and all. As with most vacations it's been a time partially filled with playing with technology and learning stuff there isn't (legitimate) time to learn about during the rest of the year. So, lest the rest of this post make you think I ONLY play with web stuff :-) I present to you a short list of REALLY good other things from the past few weeks:... [More]
|
zAAP CPU Time Bug in Type 72 Record - OA29974 Is The Cure
If you use RMF Postprocessor you won't see this one. If you use Service Units rather than CPU seconds fields in the SMF 72-3 record you also won't see it. It's only if (like me) you use the CPU time for zAAPs in your CPU Utilisation calculation that you'll run into this problem.
If you examine fields R723IFAT (zAAP CPU Time) and R723IFCT (zAAP on GCP CPU Time) you might find them zero when you... [More]
|
Plan Your ESQA Carefully For z/OS Release 11
Thanks to Marna Walle for pointing out this change: In z/OS Release 11 there is a requirement for an additional 1608 bytes of ESQA per address space. To put that in context, I'll do some obvious maths: That's about 1.6MB per 1000 address spaces. It just might be of interest to certain customers I know with thousands of CICS regions in a system, or very large TSO or Batch systems. It's probably not... [More]
|
DFSORT Does JOIN
A new set of function was recently made available for DFSORT via PTFs UK51706 and UK51707. In this post I want to talk about the new JOINKEYS function, and try to add a little value by discussing some performance considerations. I've had the code for a couple of months and have played with it but not extensively. So much of what follows is based on thinking about the function (described in this... [More]
|
Channel Performance Reporting
Our channel reporting has consisted forever of a single chart. Before I tell you what the chart looked like I'll hazard that your channel reporting was about as bad. :-)
See, it's not something people tend to put much effort into.
Our one-chart report basically listed the top channels, from the perspective of the z/OS system under study, ranked by total channel utilisation descending - as a... [More]
|
A Few Thoughts On Parallel Sysplex Test Environments
There's a pattern I've seen over a number of test Parallel Sysplex environments over the past few years, a couple of them in situations this year: It's not much use drawing performance inferences from test environments if they're not set up properly for performance tests. Sounds obvious, doesn't it? There are two problem areas I want to draw your attention to: Shared Coupling Facility Images If... [More]
|
DDF Performance - Version 3 - but still highly relevant
I've just submitted a set of slides to Slideshare. They're not mine, they're not new, they're not even in a modern format. But they are a very good presentation worth preserving... In 1993 Curt Cotner presented a set of slides on the new DDF Inactive Thread support in Version 3 of DB2. It's still highly relevant and this support was the base on which the Version 4 WLM classification line item was... [More]
|
Hello World Again!
Apologies for being away. For a while I couldn't get the blog to operate - as an author. And then I gave up trying. :-( Count this as a "testing 1-2-3" post but also as notice I intend to back with more (hopefully useful) content soon. MUCH has happened in the "intermission". :-)
|
