Db2 for z/OS (Maintenance) Update - GSE Young … Maintenance_Update_GSE...Applies to V11, V12, V11+ V12 PI94236 Db2 sysplex workload balancing support for multi - factor and passticket

© 2019 IBM Corporation

Db2 for z/OS (Maintenance) Update

Bart Steegmans Db2 for z/OS Performance – Dec 2019

© 2019 IBM Corporation2

Agenda

This (short) session focussed on what is new in Db2 for z/OS 11 and 12 Applying maintenance in Db2 12 vs. 11 Limited to the highlights since the last GSE meeting-Jun 2019

Remember: Db2 11 End of Service date is 9/2020

Don’t forget to check for missing HIPERs, missing PE fixers on a regular(weekly) basis Use APAR Rating - ZSAx keyword


Applying Db2 12 maintenance


Fewer APARs and fewer field APARs in Db2 12

0

1000

2000

3000

4000

5000

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71

APAR submission totals by month since GA

V11 Total V11 Field V12 Total V12 Field


No increase in number of PE PTFs

0

10

20

30

40

50

60

J F M A M J J A S O N D

Cumulative PE/Y APARs

2015 2016 2017 2018 2019


PTF sizes

APARs in general do not have more parts in 12 than in 11− No evidence of increase in size of defect PTFs− Avg. 3.5 parts/APAR in 2019

NF APARs− 68 total, avg. 24 parts/APAR in 2019− Median is only 4− Skewed by a few large APARs

• PH09857 – 114 parts• PH09797 – 252 parts


A tale of a PE PTF

PH01819

UI62040 UI62038

V11 V12


A tale of a PE PTF – V11 thread

UI62040

UI62044 UI62491

UI62781


A tale of a PE PTF – V12 thread

UI62038

UI62486 UI63561

UI63689

UI62663

UI64401 UI63708 UI63593UI62663


Summary

The primary maintenance issue on Db2 12 is not the number of PEs, nor the impact on systems from encountering a PE – it is the impact on the ability to apply service caused by the size of new function PTFs


Actions - improving quality

Improve APAR review and testing Identify soft spots to improve serviceability and testing

− E.g. FTBs, IAG2 Effective escape analysis Detailed APAR problem description as early as possible Longer term, Db2 simplification strategy will help


Actions – reducing PE impact

Split APARs into smaller pieces Resolution of PE/Y APARs to be prioritized over other work Detailed problem description in APARs as early as possible Release fixing PTFs early if considered safe


Recent maintenance/enhancements


New Function levels FL 505 (new catalog level – enabling APAR PH09191 –

June 2019)− Improved Hybrid Transactional Analytical Processing performance − Rebind phase-in for packages that are being used for execution− New built-in functions for encryption and decryption with key labels− Improved support for DECFLOAT columns− Improved RUNSTATS performance with automatic page sampling by

default (already discussed last time but the FL changes the default)− Temporal and archive transparency support for WHEN clause on triggers

FL 506 (enabling APAR PH16829 - Oct 2019)− Alternative function names support− Support for implicitly dropping explicitly created universal TS and LOB

table spaces


Bind phase-in of rebound packages - 1 REBIND PACKAGE generates a new copy (copy ID) Existing threads continue to execute the current copy of the

package, which becomes the phased-out copy New threads (that start after rebind commits) will use the new

copy of the package Threads that existed prior to the REBIND can also use the new

current copy when they release the phased-out copy (based on the RELEASE(COMMIT) or RELEASE(DEALLOCATE) option Db2 can generate up to14 copies to phase in

− Current copy (copy ID) is in SYSPACKAGE. − Phased-out copies (and the original and previous copies) are stored in

SYSPACKCOPY and other catalog tables until they are deleted.


Bind phase-in of rebound packages - 2 REBIND PACKAGE detects when a phased-out copy can be

safely deleted, and its copy ID can be reused. The maximum copy ID is 16.− When all 16 copy IDs are in use, next REBIND fails with DSNT500I

message, reason code 00E30307. REBIND phase-in is supported for the following options:

− APREUSE(NONE) PLANMGMT(EXTENDED)− APREUSE(WARN) PLANMGMT(EXTENDED)

APREUSESOURCE(CURRENT)− APREUSE(ERROR) PLANMGMT(EXTENDED)

APREUSESOURCE(CURRENT) Package is NOT for a trigger, SQL SP, or scalar SQL UDF


Function level independent enhancements – 1 Applies to V11, V12, V11+ V12 PI94236 Db2 sysplex workload balancing support for multi-

factor and passticket authentication PH10415 retrofitts PARTITION-INFO in DSNI031I message to

V11 PH13045 - Db2 raises the limit of RATIO on the ALTER

GROUPBUFFERPOOL command from 255 to 1024 and the default value of RATIO from 5 to 10. PH11255 - Support for utility concurrency between REORG

SHRLEVEL CHANGE and LOAD RESUME SHRLEVEL CHANGE− Both can now run concurrently against the same data base object.− REORG still requires exclusive control of target object in the last LOG

iteration and SWITCH phase typical drain/claim serialization control


Function level independent enhancements – 2 Applies to V11, V12, V11+ V12 PH13527 - REORG NOCHECKPEND SUPPORT

− When the REORG utility is discarding records from the parent table of at least one referential integrity relationship, REORG avoids setting the dependent table spaces into the CHECK-pending status.

− Applies only when REORG is discarding records from a parent table, and is ignored otherwise.

− NOCHECKPEND does not remove any CHECK-pending status that was set prior to the REORG.

PH14064 – Support in ADMIN_INFO_SQL to use new CSP CASE numbers (instead of PMRs) PH16429 – (11/2019) – FTB – 00C90101 - During IX split or

page delete, if the thread is canceled after the IX tree structure is updated but before the FTB is updated, the FTB info will become inconsistent with the index tree structure


Function level independent enhancements – 3 Applies to V11, V12, V11+ V12 PH13905 - When the -START RLIMIT with SCOPE(GROUP)

option is used, subsequent I/D/U to the active RLF table triggers the refresh of the in-memory RLF table in each member. The refresh process in members where the update was not done left internal (catalog lookup) control blocks. When many of these internal control blocks are left, CPU consumption will increase as DSNXKAC1 has to go through these control blocks. PH18702 - AREST was reset before all postponed abort UR

completed – still open (on Nov 26)


Db2 12 SUP tape available Like with previous versions, SMP/E SUP (service update)

product base tape for new SMP/E installation of Db2 12 for z/OS is available.− The new Db2 12 base product tape was cut on July 30, 2019

(PDO1930), and integrates maintenance that enables you to activate function levels up to function level 505.

− Integrates 1,070 Db2 12 PTFs (more than 33 months of maintenance) − Db2 development also evaluated each of the 640 ++HOLDs from the

integrated PTF maintenance and reduced the number of ++HOLDs for you to evaluate to just 21 items

IRLM 2.3 was also SUP’d− Integrates 75 IRLM PTFs delivered in the past 68 months

New SMP/E product base tape (Db2 and IRLM) available for all Shopz orders starting Friday, October 4, 2019


PH08482 - Make clientApplCompat optional (not new) Discussed last time – but there was more to come Make clientApplCompat optional for Db2 Connect 11.1 fixpack 1 or higher History

− The APPLCOMPAT value determines the set of capabilities that the client application can use

− If the APPLCOMPAT value for the client or driver packages is V12R1M500 or less, you do not need to set the client application compatibility value (clientApplCompat)

− However, if the APPLCOMPAT value for the client or driver packages is V12R1M501 or greater, you must set the clientApplicationCompat value. The client application compatibility value must be V12R1M500 or greater.

With PH08482 − Makes setting clientApplCompat optional


PH15092 – Downlevel access via Db2 gateway SQLCODE -30025 when a down level client accesses a Db2 12 for z/OS

server via a Db2 Connect gateway Enhances PH08482 Db2 12 only considers the level of the adjacent partner

− Directly connected client environment or − Db2/LUW Connect gateway environment.

Allows a down level client (less than V11.5.1) to execute packages with APPLCOMPAT(V12R1M501) or higher when it accesses a Db2 12 for z/OS server via a V11.5.1 (or higher) DB2/LUW gateway


New IBM Cognitive Support Platform – Since Aug

https://www.ibm.com/mysupport

AKA a new system for support cases, tickets, PMRs

https://www.ibm.com/mysupport


Use the KC (Knowledge Center) – It’s great !

PH09857

https://www.ibm.com/support/knowledgecenter/en/SSEPEK/db2z_prodhome.html

https://www.ibm.com/support/knowledgecenter/en/SSEPEK/db2z_prodhome.html


Appendix


APAR Rating - ZSAx keyword

New keyword added to PE and HIPER APARs In addition to other keywords that are being used Introduced to provide a “rating” to try and help customers

determine when to apply a particular HIPER/PE PTF The ZSA keyword is under APAR Error Description, usually

as an 'Additional Keyword' ZSA ratings, ZSA1 (low), ZSA2, ZSA3, ZSA4, ZSA45, ZSA5

(highest) described below


APAR Rating - ZSAx keyword – Per Type System Outage: 4.5 and 5 is an example for adding the consideration for the number of customer who

has hit the problem, it should be the same for other HIPER category− 4: system outage should automatically get a 4− 4.5: If there are 1-5 customer already hit the problem− 5: If there are more than 10 customer already hit the problem

Data Loss:− 4: non-recoverable or pervasive, common− 3: recoverable, incorrout output, but with few conditions− 2: recoverable, incorrout, but fairly rare to hit it− 1: super rare cases

Function Loss:− 4: pervasive causing application outages− 3: likely common− 2/1: rare

Performance:− 4: looping indefinitely− 3: degrades >=5%− 2: degrades <5%− 1: not noticeable

Pervasive:− 4: automatically

MSysplex:− 4: automatically

Db2 for z/OS (Maintenance) Update - GSE Young … Maintenance_Update_GSE...Applies to V11, V12, V11+ V12 PI94236 Db2 sysplex workload balancing support for multi - factor and passticket

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