A fix is available
APAR status
Closed as program error.
Error description
AbendU1029 in DBFXWU30 because EPSTSLCT for target EPST is negative ( x'FFFFFFFF'). BALGEPST chain is looped with target EPST pointed to by BALGEPST and EPSTHNXT points to itself. This appears to be an error in the shared queues logic in DBFHGU10. The current BALGEPST value is loaded before ISWITCHing to CTL to complete the dequeue. Before redispatch, the this EPST, and the next EPSTs on chain, may be posted and begin to run. When EPSTHNXT is loaded after the ISWITCH as new value' for CS onto BALGEPST, it may point to a running EPST. Timing may be such that the 'old' BALGEPST value, which is a running EPST, may be back in BALGEPST since that EPST may have completed transaction and re-enqueued itself. The EPST loaded from EPSTHNXT may still be running. The CS will now work, possibly orphaning some EPSTs, but BALGEPST will now point to a running EPST. When that EPST finishes and reenqueues itself on BALGEPST, it will create the situation where BALGEPST points to EPST which points to itself. This will then lead to an abendU1029 as this EPST is repeatedly DBFWAKE'd.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: IMSFP V11 EMH IFP Shared Queues users. * **************************************************************** * PROBLEM DESCRIPTION: ABENDU1029 DBFXWU30, * * EPSTSLCT=X'FFFFFFFF' IN IFP SHARED * * QUEUES ENVIRONMENT. * **************************************************************** * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF * **************************************************************** This service corrects an ABEND U1029 in DBFXWU30 because EPSTSLC for target EPST is negative ( x'FFFFFFFF'). BALGEPST chain is looped with target EPST pointed to by BALGEPST and EPSTHNXT poin ts to itself. This appears to be an error in the shared queues logic in DBFHGU10. The current BALGEPST value is loaded before ISWITCHing to CTL to complete the dequeue. Before redispatch, the this EPST, and the next EPSTs on chain, may be posted and begin to run. When EPSTHNXT is loaded after the ISWITCH as new value' for CS onto BALGEPST, it may point to a running EPST. Timing may be such that the 'old' BALGEPST value, which is a running EPST, may be back in BALGEPST since that EPST may have completed transaction and re-enqueued itself. The EPST loaded from EPSTHNXT may still be running. The CS will now work, possibly orphaning some EPSTs, but BALGEPST will now point to a running EPST. When that EPST finishes and reenqueues itself on BALGEPST, it will create the situation where BALGEPST points to EPST which points to itself. This will then lead to an abendU1029 as this EPST is repeatedly DBFWAKE'd.
Problem conclusion
GEN: KEYWORDS: *** END IMS KEYWORDS *** The following change has been make to correct the reported problem: DBFHGU10: Add code to reload value of BALGEPST after ISWITCH'ed to CTL for serialization.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PM93182
Reported component name
IMS V11
Reported component ID
5635A0200
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2013-07-17
Closed date
2013-07-25
Last modified date
2013-08-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
DBFHGU10
Fix information
Fixed component name
IMS V11
Fixed component ID
5635A0200
Applicable component levels
R100 PSY UK96131
UP13/07/26 P F307 ¢
Fix is available
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Document Information
Modified date:
02 August 2013