Author Archives: Martin Packer

(Originally posted 2011-12-18.) JVM-based languages have an interesting property for z/OS programmers: They are zAAP-eligible. As we all know zAAP Eligibility brings a number of benefits – including the licence charge benefits and the ability to run on a full-speed processor even when your general-purpose processors are subcapacity ones. (I’ll briefly mention zAAP-on-zIIP here forContinue reading “Java’s Not The Only JVM-Based Language”

(Originally posted 2011-12-16.) This is the post I was going to write before the discussion that led to CICS VSAM Buffering arose. It’s about getting more insight into how WLM is set up and performing than RMF Workload Activity Report data alone allows. I recognise some of this can be done with the WLM policyContinue reading “What’s In A Name?”

(Originally posted 2011-12-16.) Four score and seven years ago (or so it seems) 🙂 the Washington Systems Center published a set of mainframe Data-In-Memory studies. These were conducted by performance teams in various IBM labs and were quite instructive and inspiring. I wish I could find the form number (and a fortiori a PDF version)Continue reading “CICS VSAM Buffering”

(Originally posted 2011-12-12.) As I said in this post I recently came across the need to handle Unicode when processing DB2 Accounting Trace (SMF 101). I was astonished not to have run into it before in all my many sets of customer data. So I had two things to do: Understand the circumstances under whichContinue reading “DB2 Accounting Trace And Unicode”

(Originally posted 2011-12-09.) In my experience there are two kinds of CICS installations: Those that take CICS down at night – to run the Batch – and those that don’t. There is a loose correlation between what the data manager is and which approach is taken: VSAM-based CICS applications tend to be less 24×7 thanContinue reading “CICS and Batch”

(Originally posted 2011-12-05.) I don’t know how many years it’s been since DB2 Version 8 was shipped but I’ve FINALLY added support for some really useful statistics that became available with that release. As so often happens I was caused to open up my code because of some customer data that exposed a problem inContinue reading “DB2 Package-Level Statistics and Batch Tuning”

(Originally posted 2011-11-20.) The very first computer game I ever played was called Rhino and it ran on a Commodore PET. The school had been lent one for a fortnight. (I don’t know why as we didn’t go on to buy any, instead getting a single RML 380Z.) Imagine a character-grid screen where the rhino’sContinue reading “Rhino’s”

(Originally posted 2011-11-04.) I don’t think I’ve mentioned this before in this blog but Tivoli Workload Scheduler (TWS) has a nice "WLM Integration" feature. With it TWS can change the Service Class a job runs in – before submission. The main purpose of this is to elevate Critical Path work. We wrote about this inContinue reading “Tivoli Workload Scheduler and Workload Manager Service Classes”

(Originally posted 2011-10-25.) One of the nice enhancements in z/OS Release 13 JES2 was the support for SYSIN in a JCL procedure. (See here for the announcement letter.) I have a personal example of where it would’ve been handy. You probably have your own. We used to distribute sample JCL to use DB2 DSNTIAUL toContinue reading “SYSIN In A Proc – New With z/OS Release 13 JES2”

(Originally posted 2011-10-20.) I mentioned APAR OA21140 before – here. It’s quite an old APAR and so it will (in all likelihood) be on your systems. I’d like to draw your attention to a subtle 1-byte field in the SMF 74 Subtype 4 (Coupling Facility Activity) record: R744FLPN. It’s the partition number for the couplingContinue reading “A Small Step For RMF, A Giant Leap For Self-Documenting Systems”