1. Copyright © 2003 Best Customer Solutions, Inc.1 z/OS Release 4 Migration: Performance Tips and Gotchas Search390.com Webcast Jim Schesvold Best Customer Solutions, Inc. jschesvold@mainframehelp.com http://www.mainframehelp.com

2. Copyright © 2003 Best Customer Solutions, Inc. 2 AGENDA Criteria & Format Virtual Storage Topics WLM Topics JES2 Topics DFSMS Topics Miscellaneous Topics Q&A This is a tongue-twister!

3. Copyright © 2003 Best Customer Solutions, Inc. 3 CRITERIA & FORMAT Focus is on a “vanilla” migration and what performance issues might arise as a consequence This includes possible hardware changes (upgrades) Releases covered -- OS/390 V2R9 through z/OS V1R4 Release is identified wherever possible –PTF may be retrofitted to prior releases Does not include implementation of new function (64-bit, hipersockets, etc.) This is not a tuning presentation Grouped by VS, then z/OS element Reference material is identified –Hiperlinks are active on Slide Show

4. Copyright © 2003 Best Customer Solutions, Inc. 4 VIRTUAL STORAGE

5. Copyright © 2003 Best Customer Solutions, Inc. 5 SQA SHORTAGE DETECTION APAR OW54022 replaces OW50225 as of 6/5/2002 OW50225 –Changes detection levels, does not relieve shortage –Thresholds are used to notify SRM of a CSA shortage –SQA Shortage (IRA100E) changed from 32K to 512K –Critical SQA Shortage (IRA101E) changed from 16K to 128K –Invokes storage recovery routines earlier during depletion –Can cause unnecessary IRA100E, IRA101E messages OW54022 –Released to address unnecessary messages problem –Cuts threshold sizes in half –Provides mechanism to change threshold values Change IGVDCLIM CSECT constants in IEAIPL04 OW50225 includes an approach to identify cause

6. Copyright © 2003 Best Customer Solutions, Inc. 6 SQA SHORTAGE DETECTION Effective Version –OS/390 V2R10 –See APAR for correct PTF References –For all APARS in this webcast, visit IBM Technical Support Search, at http://www-1.ibm.com/support/search/index.html, then use the APAR number as the search keyword http://www-1.ibm.com/support/search/index.html –Hiperlink will be IBM Technical Support Search for the rest of the slidesIBM Technical Support Search –z/OS & OS/390 Performance Hot Topics, Kathy Walsh, p. 6, at ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf

7. Copyright © 2003 Best Customer Solutions, Inc. 7 PDSE ECSA REDUCTION Moves PDSE control blocks from ECSA to new SMSPDSE Address Space –Between 1K and 2K per MEMBER –1,000’s of members = Megabytes of ECSA –IEBCOPY or user BLDL programs access all members at 1 time SMXC and SYSBMFAS processing has also been moved to SMSPDSE End Of Memory processing now uses Cancel code –Higher PDSE reliability after user Address Space is forced Available via APAR OW53235 plus multiple child APARs –Visit IBM Support and search on UW99418 –PDO service type put tape for PDSE, see II13336 More relief is to come, see II12791

8. Copyright © 2003 Best Customer Solutions, Inc. 8 PDSE ECSA REDUCTION Effective Version –OS/390 V2R10 –UW99418 for z/OS V1R3 and V1R4 –UW99417 for OS/390 V2R10, z/OS V1R1 and z/OS V1R2 References –IBM Technical Support Search, use APAR # or PTF # as search keywordIBM Technical Support Search –Migrating to z/OS V1R4 - Parts 1 and 2, Marna Walle, p. 98, at http://docs.share.org/proceedings/sh100/s2871.pdf http://docs.share.org/proceedings/sh100/s2871.pdf –z/OS V1R4 Migration Guide, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/10.3.1 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/10.3.1

9. Copyright © 2003 Best Customer Solutions, Inc. 9 TCP/IP & VTAM PQ52813 - ECSA, ESQA Shortage due to IPMAIN contention OA01756, OA01656 - CSA, ECSA, TIBUF growth OW52758 - SP 231 Key 6 growth exhausts CSA II11553, II12658 - TCP/IP storage, TCP/IP CSM APAR index II13442 - VTAM CSM APAR index –Includes technique for coding IVTPRM00 Effective Version - OS/390 V2R10 & up depending on PTF References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –z/OS & OS/390 Performance Hot Topics, Kathy Walsh, p. 16, at ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf

10. Copyright © 2003 Best Customer Solutions, Inc. 10 z/ARCHITECTURE ESQA 64-bit and z/Series (with z/OS) go hand in hand –Bimodal Migration Accommodation offering = 6 month cutover OW56566 - ESTOR ESQA no longer exists –Allocated at IPL for ESTOR mgt., residual portion available –Reduction is about 8M ECSA per 1G of ESTOR If ESQA/ECSA is tight, this could cause a shortage Can cause S878 & S80A abends, or wait state Effective Version - OS/390 V2R10 with z/Series References –IBM Technical Support Search, use OW56566 as keywordIBM Technical Support Search –z/OS & OS/390 Performance Hot Topics, Kathy Walsh, p. 6, at ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf –z/OS V1R4 Migration Guide, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/2.2.15 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/2.2.15

11. Copyright © 2003 Best Customer Solutions, Inc. 11 OTHER VS ITEMS OW53508 - SMS SQA/CSA storage creep (OS/390 V2R10) –Due to UCB capture w/Dynamic IO Configuration Environment –IBM Technical Support Search, use OW53508 as keyword Switchable, namable TSO Broadcast Data Set (z/OS V1.3) –Unavailability of SYS1.BRODCAST could deplete CSA –z/OS V1R4 Migration Guide, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/5.2.6 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/5.2.6 –z/OS 1.3 User Experiences at Boeing, Deborah Barnes, p. 19, at http://www.share.org/proceedings/sh99/SHARE/data/S2868b.pdf http://www.share.org/proceedings/sh99/SHARE/data/S2868b.pdf Review Virtual Storage settings (all releases) –z/OS V1R4 Migration Guide, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/2.2.10 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/2.2.10 –z/OS V1R4 Planning for Installation, at http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/e0z2b132/6.3.6 http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/e0z2b132/6.3.6 –z/OS V1R4 MVS Initialization & Tuning Guide, at http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/iea2e110 http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/iea2e110

12. Copyright © 2003 Best Customer Solutions, Inc. 12 WORKLOAD MANAGER

13. Copyright © 2003 Best Customer Solutions, Inc. 13 VELOCITY CALCULATION OW47277 (z/OS V1R1) –Calculations are changed for: LPAR CPU Management inequities Softcapping, especially responsiveness –This may lower velocities for systems running in LPAR mode –Velocity goals may need to be lowered as a result –OW48268, OW55665 have multiple fixes, minimize velocity impact –OW57249 fixes S0C9 when COMPAT is used Can be key when running a sysplex with both OS/390 & z/OS –Execution Velocity Migration Tool can be found at http://www.ibm.com/servers/eserver/zseries/zos/wlm/tools/velocity.html http://www.ibm.com/servers/eserver/zseries/zos/wlm/tools/velocity.html References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –Cheryl Watson’s Hot Flashes #9, pp. 17-18, at http://docs.share.org/proceedings/sh100/s2543.pdf http://docs.share.org/proceedings/sh100/s2543.pdf

14. Copyright © 2003 Best Customer Solutions, Inc. 14 INITIATOR PRIORITY OW55344 (OS/390 V2R10) –INIT priority is set via PVLDP in IEAIPSxx for COMPAT –Originally, INITs ran in SYSSTC service class for GOAL Dispatching priority was fixed at 254 –When CPU intensive exits run before job select under an INIT, it runs at priority 254; this can interfere w/online, other key work –OW55344 adds INITIMP parameter in IEAOPTxx that sets dispatching priority of SYSSTC, plus writeup on how to use it OA03581 fixes OW55344 –If not using INITIMP, last batch priority is used versus 254 –Circumvention is to set INITIMP (0, 1, 2, 3, or E, not priority) References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –Cheryl Watson’s Hot Flashes #9, p. 19, at http://docs.share.org/proceedings/sh100/s2543.pdf http://docs.share.org/proceedings/sh100/s2543.pdf

15. Copyright © 2003 Best Customer Solutions, Inc. 15 FEWER, FASTER CP’S Moving to a processor w/fewer, faster CPs –High priority, single-TCB (or close to it, like CICS) applications can now consume more of a processor’s capacity –This is a problem when that’s not the objective WLM can control high priority, single-TCB application –For COMPAT, use time slicing (TSPTRN in IEAIPSxx) –GOAL mode uses performance objectives within a service policy –Resource Groups can provide even more control References –Cheryl Watson’s Hot Flashes #9, p. 19, at http://docs.share.org/proceedings/sh100/s2543.pdf http://docs.share.org/proceedings/sh100/s2543.pdf –Performance When Moving to Fewer, Faster CPs, Walt Caprice Jr., at http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP100258 http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP100258 –Cheryl Watson’s Tuning Letter - 1998, No. 6: Sizing Processors, pp. 14-23, at http://www.watsonwalker.com/tl9806.pdf http://www.watsonwalker.com/tl9806.pdf

16. Copyright © 2003 Best Customer Solutions, Inc. 16 OTHER WLM ITEMS Do not define WLM softcapping unless it’s used (z/900) –This is specified on LPAR Change Logical Partition Controls panel –Performance, throughput problems may arise –WLM Soft Capping for Sub Capacity Pricing, Kathy Walsh, at http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10099 http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10099 OW47667 - Remove I/O disconnect time from velocity formula if using I/O priority management (OS/390 V2R8) –This increases velocity due to non-productive time –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –WLM Implications W.R.T. APAR OW47667, Jim McCoy, at http://www-1.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10101 http://www-1.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10101 –z/OS & OS/390 Performance Hot Topics, Kathy Walsh, p. 10, at ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf

17. Copyright © 2003 Best Customer Solutions, Inc. 17 JES2

18. Copyright © 2003 Best Customer Solutions, Inc. 18 $#POST WITH $#BUSY $#BUSY macro is enhanced to include $CKPT (if appropriate) and $#POST when BUSY=OFF (z/OS V1R4) $#BUSY sets/tests busy indicator for job output element If you already have coded $#POST (as you should, but many didn’t), you now execute 2 $#POSTs $#POST is a costly call Existing $#POST should be removed References –z/OS V1R4 Migration, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/13.2.21 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/13.2.21 –z/OS V1R4 JES2 Migration, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/has2e130/5.1.7.1 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/has2e130/5.1.7.1 –z/OS V1R4 JES2 Macros, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/has2c220/CCONTENTS http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/has2c220/CCONTENTS

19. Copyright © 2003 Best Customer Solutions, Inc. 19 OTHER JES2 ITEMS OA02686 - High CPU using HASPPSO (z/OS V1R4) –ISV External Writer packages like SAR, QSERV, etc. use PSO interface –Also see IBMLINK item RTA000053488 (20% increase fixed with tuning) OW54137 - High CPU using SYSOUT application programming interface (SAPI) (z/OS V1R4) –Improper handling of invalid Job Output Element (JOE) –Occurs after system crash or JES2 error –SAPI application appears to be hung OW55693 - Slow JES2 processing w/IXCQUERY (z/OS V1R4) –IXCQUERY -- Obtain XCF Information (Sysplex service to Coupling Facility Structure) –Apply fix or run JES2 checkpoint on DASD References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search

20. Copyright © 2003 Best Customer Solutions, Inc. 20 DFSMS

21. Copyright © 2003 Best Customer Solutions, Inc. 21 VSAM INDEX CISIZE Size calculation has changed (z/OS V1R3) –Size may increase; for example from 1536 to 2560 –Can increase LSR storage requirements, in some cases up to 30% –LSR pools may need to be redefined, both buffer and buffer pool size(s) –CICS VSAM files, IMS databases may be affected –The change attempts to improve the chance an index record represents all data Control Intervals in a data Control Area References –z/OS V1R4 Migration, at http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/10.1.2 http://publibfp.boulder.ibm.com/cgi- bin/bookmgr/BOOKS/e0z2m101/10.1.2 –z/OS V1R3 DFSMS: Using Data Sets, at http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/dgt2d410/2.5.1.3 http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/dgt2d410/2.5.1.3 –Search390.com: Ask The Expert, Jim Schesvold, at http://search390.techtarget.com/ateQuestionNResponse/0,289625,sid10_cid5 14970_tax292523,00.html http://search390.techtarget.com/ateQuestionNResponse/0,289625,sid10_cid5 14970_tax292523,00.html –VSAM Cluster Index CI Size Calculation Change, Charlie Burger, at http://www-1.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10206 http://www-1.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10206

22. Copyright © 2003 Best Customer Solutions, Inc. 22 DFSMSdss COPY OW55383 - Improved FULL Volume COPY Performance (OS/390 V2R10) –Specifying ADMINISTRATOR, ALLDATA(*), ALLEXCP bypasses read of source VTOC tracks –Specifying ADMINISTRATOR, PURGE bypasses read of the target VTOC –Specifying ADMINISTRATOR, ALLDATA(*), ALLEXCP, PURGE bypasses read of both source and target VTOC tracks –The larger the VTOCs, the greater the improvement –Improvement is greatest when using FlashCopy or SnapShot References –DFSMSdss Full volume Copy Performance Enhancement, Charlie Burger, at http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10206 http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/Flash10206 –IBM Technical Support Search, use OW55383 as keywordIBM Technical Support Search –z/OS V1R3 DFSMSdss Storage Administration Reference, at http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/DGT2U211/7.4.3 & http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/DGT2U211/7.4.4 http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/DGT2U211/7.4.3 http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/DGT2U211/7.4.4

23. Copyright © 2003 Best Customer Solutions, Inc. 23 VSAM Striped Data Sets OW50528 - Secondary space allocation performance improvement –Extents are now released on primary volume at VSAM RESET –Guaranteed space data sets will release extents on guaranteed space volumes if not part of primary allocation –KSDS index component will also be reset –Striped data sets can now also use REUSE OW51353 - Fixes OW50528 problem with REUSE and IMBED References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –Migrating to z/OS V1R4 - Parts 1 and 2, Marna Walle, p. 122, at http://docs.share.org/proceedings/sh100/s2871.pdf http://docs.share.org/proceedings/sh100/s2871.pdf

24. Copyright © 2003 Best Customer Solutions, Inc. 24 MISCELLANEOUS ITEMS

25. Copyright © 2003 Best Customer Solutions, Inc. 25 GRS WILDCARD SUPPORT OW49979 - Compatibility support for GRS wildcard capability packaged in z/OS V1R2 –Extends support back to O/390 V2R8 –Also includes performance enhancements and fixes to GRS wildcard support in z/OS V1R2 –Performance problems in ISGNQXIT exit, up to 20% CPU increase OW52896 - Additional performance enhancements –More improvements to ENQ/DEQ with SCOPE=STEP OW56809 fixes S738 abend caused by OW52896 II13047 - Fixes to address a hole closed by OW49779 References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –Cheryl Watson’s Hot Flashes #8, p. 11, at http://www.share.org/proceedings/sh99/SHARE/data/S2543.pdf http://www.share.org/proceedings/sh99/SHARE/data/S2543.pdf

26. Copyright © 2003 Best Customer Solutions, Inc. 26 RACF, USS UID/GID SEARCH If sharing RACF DB with pre-OS/390 V2R10 systems, use UNIXMAP class + IRRUMAP, IRRGMAP VLF classes –Avoids sequential search of RACF DB for UID or GID associations If all systems are OS/390 V2R10 or higher, conversion to Application Identity Mapping stage 3…… –Can improve performance even more –Can eliminate need for UNIXMAP, IRRUMAP, IRRGMAP –IRRIRA00 conversion utility is used to migrate to AIM stage 3 References –z/OS Release 3 and 4 Implementation, page 180, at http://www.redbooks.ibm.com/redbooks/pdfs/sg246581.pdf http://www.redbooks.ibm.com/redbooks/pdfs/sg246581.pdf –Optimizing RACF Performance, Walt Farrell, p. 7, at http://www.ibm.com/servers/eserver/zseries/zos/racf/pdf/r00_tuning_racf.pdf http://www.ibm.com/servers/eserver/zseries/zos/racf/pdf/r00_tuning_racf.pdf –z/OS 1.4 User Experience at Boeing Company, Deborah Carnes, p. 25, at http://docs.share.org/proceedings/sh100/s2868b.pdf http://docs.share.org/proceedings/sh100/s2868b.pdf

27. Copyright © 2003 Best Customer Solutions, Inc. 27 MVS LOGGER PQ48163 - Delays on Logger Writes using CF Logstreams –CICS EC WRITE JOURNAL WAIT causes task LG_DEFER suspend –Log Defer Interval (LGDFINT) in SIT defines how long to delay before forcing a Logger write (default is 5 ms.), with the objective of batching Logger writes –In low volume systems, if log defer crosses into a partition exit, task response time is increased up to region exit interval (ICV, default=1 sec.) –Circumvention is LGDFINT=0 (default OK for DASD logging) –PQ48163 does not provide a fix (fixed in a future release) PQ57850 - A fix for CICS TS V1.3 References –IBM Technical Support Search, use APAR # as keywordIBM Technical Support Search –z/OS & OS/390 Performance Hot Topics, Kathy Walsh, p. 15, at ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf ftp://ftp.software.ibm.com/software/mktsupport/techdocs/hot02.pdf

28. Copyright © 2003 Best Customer Solutions, Inc. 28 OSA EXPRESS WITH QDIO PQ53480 - High CPU consumption when using Gigabit Ethernets –VTAM cannot keep up with incoming data from OSA Express as it delivers it to TCP/IP –After delivering data to TCP/IP, VTAM checks for more. If so, another Programmed Controlled Interrupt (PCI) is simulated to read more data, & so on until all data is delivered OSA Express communicates directly with S/390 memory via data queues, hence the PCI simulation –When VTAM cannot keep up with data, PCI simulation runs constantly, using high amounts of CPU –PQ53480 changes VTAM to count # of PCI simulations it runs & reschedule/exit after unstated amount of simulations References –IBM Technical Support Search, use PQ53480 as keywordIBM Technical Support Search

29. Copyright © 2003 Best Customer Solutions, Inc. 29 LEGALITIES Performance impact of an item is dependent on your configuration, applications, volume, capacity, and environment; carefully research any item that appears to be relevant. All information is distributed on an “as is” basis, with no form of warranty either expressed or implied. IBM trademarks - CICS, CICS TS, CP, CSM, DFSMS, DFSMSdss, ESTOR, FICON, GRS, Hiperspace, IBM, IMS, JES2, LPAR, MVS, OSA Express, OS/390, QDIO, PDSE, RACF, SMS, System Resource Manager, SRM, S/390, TCP/IP, UNIX System Services, VSAM, VTAM, WLM, z/Architecture, z/OS, zSeries, z/800, z/900 Computer Associates trademark - SAR Mantissa Corporation trademark - QSERV

30. Copyright © 2003 Best Customer Solutions, Inc. 30 QUESTIONS AND ANSWERS Ask your questions now –Mark Brunelli will explain Ask your questions later –Ask the Expert on Search390.com, at http://search390.techtarget.com/ateQuestion/0,289624,sid10_cid475121_tax 292523,00.html http://search390.techtarget.com/ateQuestion/0,289624,sid10_cid475121_tax 292523,00.html Questions I can’t answer now will be, on Search390.com Email - jschesvold@mainframehelp.com Website - http://www.mainframehelp.comhttp://www.mainframehelp.com Migration Starter Kits - http://www.mainframehelp.com/upgrade_plan_templates. htm http://www.mainframehelp.com/upgrade_plan_templates. htm

31. Copyright © 2003 Best Customer Solutions, Inc. 31 QUESTIONS AND ANSWERS