A fix is available
APAR status
Closed as program error.
Error description
The customer is running MQ V7.0.1. They noticed the continual MIPs increase in the Queue Manager (QMGR) Master address space between QMGR restarts. They usually do not re-start z/OS queue managers unless there is an LPAR IPL or maintenance upgrade. The dump of the QMGR showed a large amount of MTMEs and system trace showed many entries for CSQMNMTIN. The Change Team can now see the cause of the leak of MTME control blocks. CSQMMTPR CSQM_UNMARK_MSG_TOKEN processing causes MTME_FINVALID to be set as a result of the destructive MQGET for the message (MTME_FINVALID being set means that the message can be deleted the next time the queue is processed by CSQMMTIN). However, the message is being browsed at the same time and CSQMMTPR is invoked for CSQM_MARK_MSG_TOKEN which results in MTME_FINVALID being reset. This means that the MTME will never be released, causing the problem seen here. * Additional Keywords: CPU performance storage leak Subpool 229 Key 7 SP229 KEY7 ADDITIONAL SYMPTOM : ORPHANED MTME INDICATED BY ABEND5C6 00C90600 OR 00C90900 IN CSQIMGE3 WITHOUT INCREASE IN MIPS OR STORAGE USE
Local fix
For affected JMS users using client channels, temporarily set SHARECNV=0 on the SVRCONN definition. Reference http://www.ibm.com/developerworks/websphere/library/techarticles /1110_titheridge/1110_titheridge.html After the fix is applied, SHARECNV=1 is preferred.
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ Version 7 * * Release 0 Modification 1 and * * Release 1 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Increased CPU usage and creeping * * storage usage detected in queue * * managers with applications browsing and * * marking messages like WSAS JMS MDB * * listeners, or applications using * * message selection. * * * * The following abends 5C6-00C90600 in * * CSQIMGE3 and 5C6-00C90B00 in CSQIMGE9 * * can be generated as result of this * * problem. * **************************************************************** * RECOMMENDATION: * **************************************************************** Applications browsing (MQGET with MQGMO_BROWSE_... options) and marking messages (MQGMO_MARK_BROWSE_... options) do not unmark messages selected as candidates for browsing when the browse process detects that the message has been deleted by a destructive MQGET (running in another thread) resulting in MTME (message token mark entry) records not freed causing the creeping storage usage. The abends in CSQIMGE3 and CSQIMGE9 are caused by CSQMMTIN updating cursors in the queue with the stale data found in the orphaned MTME records.
Problem conclusion
CSQIMGE3 and CSQIMGE1 have been changed to unmark message token entries (MTME) for messages deleted during the browse process before trying to get the next message in the queue. 010Y 100Y CSQEMTIN CSQIMGEG CSQIMGE1 CSQIMGE3 CSQIVALM CSQMGET CSQMMTIN CSQMMTIS CSQMMTPR
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI07866
Reported component name
WMQ Z/OS V7
Reported component ID
5655R3600
Reported release
010
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2013-12-11
Closed date
2014-03-31
Last modified date
2015-10-16
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI16580 UI16581
Modules/Macros
CSQEMTIN CSQIMGEG CSQIMGE1 CSQIMGE3 CSQIVALM CSQMGET CSQMMTIN CSQMMTIS CSQMMTPR
Fix information
Fixed component name
WMQ Z/OS V7
Fixed component ID
5655R3600
Applicable component levels
Fix is available
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Document Information
Modified date:
16 October 2015