A fix is available
APAR status
Closed as program error.
Error description
ABEND0C4 RC00000004 in DSNGEFLC when 2 thread attempt to allocate the same package at the same time. This can create a race situation (a timing bug) where one each thread attempts to get the same package section at the same time and it creates a situation where the hash chain is not handled properly. This can result in a Db2 outage with message DSNV086E and an ABEND04E RC00E50705.
Local fix
RESTORE PH09796/UI62576
Problem summary
**************************************************************** * USERS AFFECTED: * * Db2 12 for z/OS non-data sharing users * **************************************************************** * PROBLEM DESCRIPTION: * * ABEND0C4 RC04 IN DSNGEFLC OFFSET7CDC * * when two users concurrently execute * * the same package. * **************************************************************** * RECOMMENDATION: * * Apply corrective PTF when available * **************************************************************** This APAR fixes a problem in non-data sharing environment after PH09796/UI62576 is applied. When two concurrent threads execute the same package, both threads try to load the SKPT to EDM pool. When one thread finishes loading the SKPT, the other thread may incorrectly remove the SKPT from hash chain, and use a wrong pointer to insert the SKPT again, causing the above abend. This can cause a secondary ABEND0C4 RC04 in DSNGEPLC OFFSET0DD6C in recovery process, which brings Db2 down afterwards.
Problem conclusion
Db2 is changed so that SKPT is correctly loaded to EDM pool. The above abend problem is fixed.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PH13112
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
C10
Status
CLOSED PER
PE
YesPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-06-07
Closed date
2019-07-22
Last modified date
2019-08-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI64349
Modules/Macros
DSNGEFLC DSNGERBK DSNGEPLC DSNGENER DSNGEPDL
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RC10 PSY UI64349
UP19/07/26 P F907
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.
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Document Information
Modified date:
01 August 2019