A fix is available
APAR status
Closed as program error.
Error description
There is a loop problem when stopping WAS server after Admin Structure Full condition. The error in the recovery processing for the initial 5C6 abend can lead to an ACE being incorrectly left on the VLCA chain for the application address space. When the Servant region was subsequently stopped, CSQMCTXE added the context ACE to the VLCA chain, however because it was already on the chain, this led to the reported loop condition. Additional Symptom(s) Search Keyword(s):
Local fix
n/a
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 8 * * Release 0 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: High CPU loop in MQ application address * * space during termination processing * * following an earlier abend in RRS exit * * processing for that address space. * * The application address space hangs and * * cannot be canceled. * **************************************************************** * RECOMMENDATION: * **************************************************************** While an MQ RRS Exit is processing a RRS context (for example, to prepare or commit work done under the context) on behalf of an RRS application e.g. WSAS, the context ACE is added to the VLCA allied ACE chain for the address space. If the RRS exit abends, CSQ3RRSF is invoked to provide recovery processing, including removing the ACE from the VLCA chain, however an error in this recovery routine can lead to the ACE being incorrectly left on the chain. If the ACE is subsequently used again (for example during end context processing), it can be added to the VLCA chain again, leading to a loop being introduced to the chain. When the chain is subsequently processed, for example by end of task processing, or other RRS exits for the address space, the loop in the VLCA chain results in processing looping, causing high cpu. A latch is held while processing the VLCA chain, so any other tasks attempting to use this chain will be suspended due to the looping task holding this latch. This can result in the address space failing to end correctly, even when canceled.
Problem conclusion
CSQ3RRSF is changed to correctly remove the context ACE from the VLCA chain when needed. 000Y CSQ3RRSF
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI39731
Reported component name
WMQ Z/OS 8
Reported component ID
5655W9700
Reported release
000
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2015-04-23
Closed date
2015-05-12
Last modified date
2015-07-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI27544
Modules/Macros
CSQ3RRSF
Fix information
Fixed component name
WMQ Z/OS 8
Fixed component ID
5655W9700
Applicable component levels
R000 PSY UI27544
UP15/06/03 P F506 ¢
Fix is available
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Document Information
Modified date:
01 July 2015