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zAAP and zIIP Revisited (At Last)
It's been an awfully long time since I wrote When Good Work Doesn't Go To zIIP / zAAP Heaven . And too long since I posted anything at all. In fact I had a bunch of posts in my brain until this morning when a customer asked me a question which turned into this blog post. (Those posts are still in my brain and will probably see the light of day eventually, including one based on a customer... [More]
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It Depends: SMF 30 Job Timings And CPU Time
This may be stating the obvious - but I wonder to whom it actually is obvious... I've been doing quite a lot of work with batch job timings and CPU recently. (Everything I'm about to say is equally true of steps.) It's interesting to think about the effects of faster engines versus more engines (a question I haven't been asked recently) and whether a customer needs more capacity or just faster... [More]
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When Display Commands Aren't Good Enough
There've been times in the past when a request for extra data in SMF has been met by "you can issue a DISPLAY command to get that".
(Another variant is "you can go to the HMC for that".) I'm here to tell you why I don't think that's a brilliant answer: Such a command is a point-in-time thing.
Systems nowadays are much more dynamic than they were. Something as simple as... [More]
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ASCII to EBCDIC Conversion with DFSORT
( Scroll down if you're not interested in DB2 ) This past week I've been updating our SQL Analysis code to cope with Unicode SQL statements. (If you bind a package or plan once you've gone to DB2 Version 8 New Function Mode the statement text is stored in the Catalog in Unicode.) These statements are in Unicode UTF-8 which is extremely similar to ASCII. So I snaffled some existing code of mine... [More]
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DB2 Data Sharing and XCF Job Name - Revisited
It's been almost four years since I wrote DB2 Data Sharing and XCF Job Name .
It mostly stands the test of time but there are a couple of things I want to bring up. I was in the DB2 Development lab a couple of days ago, talking with a couple of developer friends about DB2 Data Sharing and XCF.
They know DB2 Data Sharing and IRLM much better than I do but XCF not so much.
(It's probable that XCF... [More]
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Would You Like More WLM Information In DB2 Accounting Trace - And How Would You Use It?
I was lucky enough to be in Silicon Valley Lab for DB2 BootCamp last week. There I ran into a DB2 developer I've worked very successfully with in the past - John Tobler. (He's the guy I look to for questions and issues with DB2 SMF data.) We had a good discussion about something I'd personally like to see in DB2 Accounting Trace - more WLM information - and this post is as a result of this... [More]
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We Have Residents!
Back in May I wrote about a new batch residency planned for this October and invited good people to apply to join the team. It's been very pleasing how many people applied to be residents and the high quality of the entrants: It was genuinely difficult to pick the eventual team. We also had to reduce the scope a bit - which was a disappointment to both Frank Kyne and I. So, if you didn't get... [More]
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You Might Just Be A Clone If...
As previously discussed I'm often in a situation of trying to make sense of a set of job-related SMF data. Even though it may be your own installation's data, you're probably confronted with what I like to call “a journey of discovery” occasionally, too. I'm always looking for what I can discern from the data. 1 And, when confronted with a set of data about batch jobs, I go into overdrive. This... [More]
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Finding The DB2 Accounting Trace Records For an IMS Batch Job Step
When tuning DB2 batch it's important to know which SMF 101 Accounting Trace record corresponds to which job step. A few years ago I wrote code to do this. It works fine for all z/OS DB2 Batch except that originated by IMS. Here's how it works: Find all the Type 30 Step-End records for a given job name. Find the Type 101 Accounting Trace records for which the Correlation ID in the 101 record... [More]
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DB2 Data Sharing and XCF Job Name
Back in z/OS R.9 RMF Parallel Sysplex New Fields (in 2007) I mentioned a new field: R742MJOB (XCF Member Job Name.) At the time I had no real customer data so I could only espouse the HOPE that this field would be useful. (When I asked for it to be added to the SMF 74 Subtype 2 record it seemed to me it probably would be.) Now that z/OS R.9 is "mainstream" I'm seeing lots of data at this level.... [More]
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Performance Numbers and the Redbook
So, I'm about to start writing. At last! As a team we had a discussion yesterday about how to deal with performance numbers. One of the roles I'm playing on the team is "the guy who writes about performance numbers". So we came to the following conclusions: We really can't talk about products made by other people - such as SAS/MXG or TMON for DB2. That's right out - because of our basic provenance... [More]
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WLM-Managed DB2 Stored Procedure Address Spaces
I was contacted by the team updating the SG24-7083 "DB2 Stored Procedures: Through The Call And Beyond" this past week. Their question was quite straightforward: "One of the statements in the book, in the chapter on WLM address space management states: To help analyze the use of resources by different types of stored procedures, you should name the server address spaces in such a way that it is... [More]
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DB2 Version 9 RLF - Not Just For SAP
Namik Hrle, the IBM Distinguished Engineer for DB2 for SAP, presented yesterday to an internal audience. (It's the first time I'd seen him present and he's a very dynamic presenter.) His presentation prompted me to download the Enhancing SAP by Using DB2 9 for z/OS Red Book . One item I'd like to pull out is the enhancements in DB2 Version 9 to RLF . RLF will cancel SQL execution for an... [More]
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He Picks On CICS
If you think this title is obscure bear in mind the original working title was "Send In The Hobgoblins". 1 When I started to write - actually before the "mind mapping" stage - it was going to be all about inconsistency in the way bits of systems are named. You'll see some of that reflected in the finished article (pun intended) but the post has mostly gone in a different... [More]
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Is It The Structure Or The Content That's Important?
The other three residents are busy doing extensive setup work - and we hope to have some nice measurements later on. (I'm not sure how much later on there actually is, mind.) :-) So I have no RMF or DB2 SMF to play with yet. :-( Meanwhile I'm beginning to come up to speed again after the glorious experience of recovering from moving five time zones to the west. :-) So I actually got to writing... [More]
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More on Coupling Facility Async / Sync Thresholds
Following on from Coupling Facility Async / Sync Thresholds - They Are A'Changin' I've been informed by Development there is a new improved write up on how the Dynamic Sync/Async conversion works in Chapter 6 of the z/OS Release 9: Setting Up A Sysplex manual. I've read it and it is VERY good. One thing to pull out is that there isn't just one threshold... There are different thresholds for Lock... [More]
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New Support for BatchPipes/MVS
As many of you know I've been very fond of BatchPipes/MVS (aka "Pipes") down the years (17 to be precise). So I'm pleased to see APAR PK34251: ADDING BATCHPIPES SUBSYS SUPPORT TO TEMPLATE UTILITY describes some new support in the DB2 Load Utility (as driven by the Template utility) which makes it much easier to use with BatchPipes/MVS. (For reference here's the BatchPipes For OS/390 Version 2... [More]
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DB2 Version 9 - STATIME Default Decreased to 5
I'm in a session where we're going through DB2 Version 9 migration considerations - and right now there's a table on display with changes to DSNZPARM defaults. One of real value is that STATIME has changed to 5 minutes from 30. Unless you've overridden it you should now get much better information at the DB2 subsystem level. This does, of course, mean 12 sets of Statistics Trace records an hour,... [More]
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Data Collection Requirements
Over the years I’ve written emails with data collection requirements dozens of times, with varying degrees of clarity. It would be better, wouldn’t it, to write it once. I don’t think I can get out of the business of writing such emails entirely but here’s a goodly chunk of it. Another thing that struck me is that the value of some types of data has increased enormously... [More]
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How Many Eggs In Which Baskets?
You wouldn’t put all your eggs in one basket, CICSwise, would you?
A naive reading of the CICS TS 5.1 announcement materials might lead you to suppose you could .
This post is about thinking about your CICS region portfolio in the light of this announcement. While every CICS release introduces capabilities that makes it worthwhile to review your region portfolio,
5.1 majors on... [More]
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Are You Being Served?
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 only their own performance numbers need to be considered for us to understand their... [More]
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Flash Saviour Of The Universe?
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 the discussions have grown more numerous recently.
So it’s time I expressed (pardon the pun) my... [More]
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DB2 Timings For CICS Transactions - With Thread Reuse
There was a time before blogging and what I'm about to talk about is something I used to explain quite often back in those days. Reminded by a current customer situation - and needing to explain it again - I thought it time to do it this way. (Here I'm presenting a simplified view, but one that covers the salient features that might help you.) The CICS / DB2 Connection code provides a number of... [More]
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Two Potential New Presentations - Coming Soon?
Every year I like to debut one new presentation, though that isn't a firm rule:
In 2012 I debuted
"Send In The Clones" (SITC) 1 and
"I Know What You Did Last Summer" (IKWYDLS), but actually
only the first one was written in 2012. Of course presentations are "slow trains coming": I widely trailed my desire to write
IKWYDLS in 2011 and finally revealed it early this year.
(In fact it... [More]
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New CPU Information In SMF Type 30 Records
Round about now you'd be expecting posts to be geared towards the recent zEC12 announcement, or perhaps CICS TS 5.1 or the DB2 11 Preview, or IDAA V3.
So what this post is about will probably have slipped by unnoticed.
After all you don't spend all your time looking for obscure New Function APARs, do you? But I think some of you will find this one of value, or at least quite interesting. (I... [More]
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Games You Can Play With Timestamps
I've written extensively in the past about what you can glean about batch suites from SMF, most notably SMF Type 30. While I don't believe SMF alone can give you the full dependency network (complete with validation) I've just added some analysis to my code that gets me a little closer. As you're probably never going to run my code the bit that would be interesting is the kind of inferences it's... [More]
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Another Usage Of Usage Information
This post is about unusual ways of using the SMF 30 Usage Data information, some of which you're certain to want if you're managing z/OS systems' performance. A long time ago I noticed character strings in SMF 30 records that looked like product names. (As is my wont I was looking at the raw Type 30 records for a different purpose and spotted them.) Some time later I figured out these were Usage... [More]
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zIIP / zAAP Capacity Planning
I'm not a capacity planner but I play one on TV 1 sometimes. A customer asked me about the subject of zAAP Capacity Planning so I thought I'd post a few thoughts here. (Almost everything I say here is equally true of a zIIP.) The main point is I don't think it terribly different from regular CPU Capacity Planning. But there are some quirks: While we do have queuing we also have Crossover. But at... [More]
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The Low Down on Up Time
I can tell when a CICS region came up - without looking at CICS-specific instrumentation. What's more I can repeat the "trick" for any of MQ, DB2, IMS, etc - and so can you . I've just started work on a new piece of reporting. I'll call it "raddrspc" as that's the name of the REXX EXEC that I'm writing. It's about address spaces - most notably long-running ones. In the... [More]
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Drawing The Line
You'd think it would be pretty simple to draw a line. Right? This post discusses an enhancement I'd like to make to my current reporting - and I'm pretty sure that technically I can do it. The question is whether I should . Consider my current "Memory by address space within Service Class" graph. Here's a sample: And here's what I think I might like it to look like: Obviously the line's... [More]
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