RE: The amazing shrinking batch window.

Hi,

We originally allowed MIDAW support to default on for z/OS R6 but
disabled it when we ran into a possibly related problem with DB2 V8 from
APAR OA15034. IMHO the default should have been disabled in R6 & R7 and
changed to enabled in R8. The problem with DB2 V8 here turned out to
produce similar symptoms but was unrelated to MIDAW. In researching the
problem we became aware of a couple APAR's we felt warranted keeping
MIDAW off in our environment. It is a cool feature if you have the
hardware (z9) & software (R6+),it should produce measurable
improvements, it should be perfectly safe for most everyone to use. We
just decided to be extra cautious and keep it disabled till we could get
fixes for some recent APARs and get those fixes rolled across the
sysplex. We have a mixed environment with both MIDAW capable (IBM) and
non MIDAW capable (HDS) DASD.

This was the one that got us concerned and caused us to disable MIDAW
initially. The PTFS became available recently and we don't have them
rolled out into the production Sysplex yet so it is still disabled in
parmlib.

APAR Identifier ...... OA15034 Last Changed ........ 06/04/03
IO ERRORS ON MULTIVOLUME LINEAR DATA SETS WITH MIDAW SUPPORT
ENABLED. D/T2094

Symptom ...... LP LOOP Status ........... CLOSED PER
Severity ................... 1 Date Closed ......... 06/02/08
Component .......... 5695DF106 Duplicate of ........
Reported Release ......... 1J0 Fixed Release ............ 999
Component Name DFSMS VSAM MEDA Special Notice HIPER
Current Target Date ..06/02/17 Flags
SCP ................... FUNCTIONLOSS
Platform ............

Status Detail: SHIPMENT - Packaged solution is available for
shipment.

PE PTF List:

PTF List:
Release 1J0 : UA24319 available 06/03/07 (F603 )
Release 1K0 : UA24320 available 06/03/07 (F603 )


Other APARs of "interest" for MIDAW.

APAR Identifier ...... OA15447 Last Changed ........ 06/03/22
COMMAND REJECT, INVALID PARM FOR A LOCATE RECORD EXTENDED
CHANNEL PROGRAM. MULTIPLE IOS000I MESSAGES RECEIVED. D/T2094

Symptom ...... MS MSGIOS000I Status ........... CLOSED PER
Severity ................... 3 Date Closed ......... 06/03/22
Component .......... 5695DF106 Duplicate of ........
Reported Release ......... 1K0 Fixed Release ............ 999
Component Name DFSMS VSAM MEDA Special Notice HIPER
Current Target Date ..06/04/30 Flags
SCP ................... FUNCTIONLOSS
Platform ............

Status Detail: TESTPACKAGING - Packaged solution is being tested.

PE PTF List:

PTF List:
Release 1J0 : PTF not available yet
Release 1J0 : Relief is available in the form of: AA15447
Release 1K0 : PTF not available yet
Release 1K0 : Relief is available in the form of: AA15447


APAR Identifier ...... OA15505 Last Changed ........ 06/04/03
2084 DISPLAYS MIDAW CHAINS IN GTF OUTPUT D/T2094


Symptom ...... IN INCORROUT Status ........... CLOSED PER
Severity ................... 2 Date Closed ......... 06/03/03
Component .......... 5752SC111 Duplicate of ........
Reported Release ......... 720 Fixed Release ............ 999
Component Name 5752 GTF Special Notice
Current Target Date .. Flags
SCP ...................
Platform ............

Status Detail: SHIPMENT - Packaged solution is available for
shipment.

PE PTF List:

PTF List:
Release 709 : UA24825 available 06/03/14 (F603 )
Release 720 : UA24826 available 06/03/14 (F603 )


APAR Identifier ...... OA15556 Last Changed ........ 06/03/31
BUILD MIDAWS IN SEPERATE PAGE FROM CHANNEL PROGRAM TO IMPROVE
PERFORMANCE IN DB2 ENVIRONMENT D/T2094

Symptom ...... NF NEWFUNCTION Status ........... CLOSED UR1
Severity ................... 2 Date Closed ......... 06/03/31
Component .......... 5695DF106 Duplicate of ........
Reported Release ......... 1J0 Fixed Release ............ 999
Component Name DFSMS VSAM MEDA Special Notice
Current Target Date ..06/05/06 Flags
SCP ...................
Platform ............

Status Detail: TESTPACKAGING - Packaged solution is being tested.

PE PTF List:

PTF List:
Release 1J0 : PTF not available yet
Release 1K0 : PTF not available yet

========================================================================
=====

Best Regards,

Sam Knutson, GEICO
Performance and Availability Management
mailto:sknutson@xxxxxxxxx
(office) 301.986.3574

"Think big, act bold, start simple, grow fast..."



-----Original Message-----
Re: batch performance, another new item in the bag of tricks is MIDAW.
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