1. Cheryl Watson’s TUNING Letter 2003, No. 5
2. Request for z990 Experiences
1. Cheryl Watson’s TUNING Letter 2003, No. 5
The forty-two page 2003, No. 5 TUNING Letter was emailed to electronic subscribers today (January 9). The print issues will be mailed next week. You can purchase a printed copy of the current TUNING Letter for $95 at http://www.watsonwalker.com. The following highlights some of what you can find in this latest TUNING Letter.
IRD CPU Management
The concept of the zSeries Intelligent Resource Director (IRD) is terrific and we think that it will enable more systems to be self-managed (which is IBM’s ultimate goal). We’ve seen the results and it seems to work quite well. Depending on how you’re running your machine today, however, you might still be able to manually manage the machine more efficiently than IRD can manage it. How will you know? Our Focus article starting on page 18 describes how to activate IRD CPU management, how to monitor it and what areas to investigate in order to avoid problems.
Management Topics
Most of this issue is quite technical, such as the focus article on IRD, but there are a few management topics that shouldn’t be missed. The first one is IBM’s extension of availability for CICS TS 2.2 (page 4). Normally a product is withdrawn from marketing as soon as a new release becomes available. In this case that should have been when CICS TS 2.3 became available on 19Dec2003. But IBM extended CICS TS 2.2 availability due to customer requests. That’s a good lesson to learn – be sure to speak up if an IBM policy causes you problems.
Many of you are moving from 9672 machines to zSeries machines, which normally involves a huge increase in storage. Performance problems can occur from this increase in memory, unless you know what to look for (page 34).
IBM has recently announced several product withdrawals, including all of the non-zSeries machines. See page 43. On the same page, you’ll find our summary of IBM’s statements of direction for z/OS, such as the removal of ISAM after z/OS 1.6.
In our previous newsletters, we’ve discussed the performance benefits of CICS threadsafe transactions. Savings mentioned on page 36 suggest that it would be worth your time to look into using this new facility.
Elsewhere in This Issue
This issue contains several dozen APARs that might affect your installation in one way or another. Take a look at them to see if they could be contributing to problems in your shop. Our News section on page 4 contains handy documentation on SMB, a method of obtaining Red Alerts via email, a new method of accessing the VSAM and catalog support data base, an updated DFSort Web site, the addition of CPU time to the WAS type 120 record, a set of extremely important PTFs for CA90, several WSC flashes and documents, important Redbooks and a new book on tuning SAS applications. We have several user experiences starting on page 30 that should help you prevent some serious problems. These include a VTS problem, some cautions related to VSAM insert logic, incorrect documentation for SMF type 42 records, a neat (and free) LLA and VLF monitor, the resolution of the GRS and CA-MIM overhead problem, and the reason for a CPU increase for some DB2 queries. Our Q & A section on page 39 covers WLM classification rules. And in What’s New? (page 43), we cover an update to software pricing.
2. Request for z990 Experiences
We hope to be finishing up TUNING Letter No. 6 next week. One of the articles is about user experiences with the z990. We would appreciate hearing of your experience. We can either keep the information anonymous or give credit. We’re specifically looking for the following:
- Are you meeting your capacity expectations (i.e. CPU time usage)? How have you been determining that? Does this apply to all workloads, or just some of them (e.g. CICS, TSO, batch, etc.).
- Have you seen changes in response times and/or throughput with the z990?
- Have you had any microcode updates to the z990?
- Are you running in z/Architecture mode (64-bit) or 31-bit mode?
- Have you had to apply any maintenance for the z990 besides the z/OS 1.4 exploitation feature?
- Is there anything else you’d like to share?
If you aren’t a TUNING Letter subscriber, but are willing to fill out our questionnaire, we’ll send you the article on the z990 when we complete it for our TUNING Letter.
While this has to do with the zSeries, rather than just z990, we’d also like to find out:
- Have you turned on IRD? How is it working for you? Any problems, vendors’ fixes?
Stay tuned!