A fix is available
APAR status
Closed as program error.
Error description
DB2DDF Defect pm75473 dpm75473 DDF threads would slow down intermittently and took more than 20 seconds to finish whereas usually it took less than one second to finish. The incoming DDF threads were queued due to the slow down and then soon MAXDBAT was reached. Then the storage shortage abends 00E20003 or 00E20016 occurred. *********************************************************** Additional Symptoms and Keywords: Short On Storage SOS Performance PERF LCBLSTKP ABEND04E AB04E S004E 04E 04E-00E20003 00E20003 RC00E20003 DSNGEPLC DSNSVBK DSNGEPLC.DSNSVBK +05EA DSNXEPM DSNSVBK DSNXEPM .DSNSVBK +05EA DSNXOTDA DSNSVBK DSNXOTDA.DSNSVBK +05EA 04E-00E20016 00E20016 RC00E20016 DSNSLD1 DSNSVSTK DSNSLD1 .DSNSVSTK+0656
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All Distributed Data Facility (DDF) users. * **************************************************************** * PROBLEM DESCRIPTION: Intermittent performance problems may * * be observed due to contention related * * to DDF communication buffer storage * * usage. * * Unpredictable, storage related, abends * * may also occur. Symptoms may include: * * . ABND=04E-00E20003, * * LOC=DSNGEPLC.DSNSVBK +05EA * * . ABND=04E-00E20003, * * LOC=DSNXEPM .DSNSVBK +05EA * * . ABND=04E-00E20016, * * LOC=DSNSLD1 .DSNSVSTK+0656 * * . ABND=04E-00E20003, * * LOC=DSNXOTDA.DSNSVBK +05EA * **************************************************************** * RECOMMENDATION: * **************************************************************** To satisfy remote application SQL activity, distributed server threads may acquire vast amounts of 64-bit shared private (communication buffer) storage. As storage utilization increases, delays of 20 seconds or more may occur when satisfying storage requests from a storage pool which has a limited number of extra blocks allowed by its definition. This may lead to application/transaction delays and/or storage related abends.
Problem conclusion
DDF initialization has been changed to increase the number of extra blocks allowed to satisfy a get storage request to match the number of blocks that are actually requested at a time. This reduces the number of storage scans and expansions necessary to satisfy a "get storage" request thereby reducing latch contention. This allows threads to get and release storage more quickly which minimizes abends due to storage shortage. This leads to an improvement in overall DDF transaction response time.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PM75473
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt
Submitted date
2012-10-19
Closed date
2013-01-24
Last modified date
2013-03-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK91168 UK91169
Modules/Macros
DSNLIINI
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEPEK","label":"Db2 for z\/OS"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.1","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.1","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
04 March 2013