A fix is available
APAR status
Closed as program error.
Error description
The customer was experiencing an increase in MIPS which was due to orphaning of MTME control blocks, which can occur when there are multiple MDB listeners processing the same queue. . The SYSTRACE showed the following: 00A92988 EXT 1005 077C1000 9C2A6096 00001005 CSQMMTIN 20090729 + x'596' in CSQMLPLM 00A92988 I/O 00662 077C2000 9C2A6028 6080C0C9 0A2702F0 00800000 CSQMMTIN 20090729 + x'528' in CSQMLPLM 00F449E0 00000000 00A92988 EXT 1005 077C2000 9C2A6028 00001005 CSQMMTIN 20090729 + x'528' in CSQMLPLM 00A92988 DSP 077C2000 9C2A6028 00000000 5B1323FC 5B1323BC CSQMMTIN 20090729 + x'528' in CSQMLPLM 00A92988 EXT 1005 077C2000 9C2A6028 00001005 CSQMMTIN 20090729 + x'528' in CSQMLPLM 00A92988 EXT 1005 077C0000 9C2A6880 00001005 CSQMMTIN 20090729 + x'D80' in CSQMLPLM . MQTHRD out showed the following: *PEB 14FDA1D8 ACE 14FDA178 CCB 1BCE7D38 TCB 00A92988 RB 00A970D8 PROG 8000 Service Task, SYSTEM 212.xxxxC00 Latch Held Mask 00000010 = (28)ASMSQL PSW 077C2000 9C2A6028 DSA 5B132248 (CSQMMTIN) 5B132248 5B55A248 00016BD8 CSQMMTIN CSQVEUS3 CSQVEUS4 . Additional Symptom(s) Search Keyword(s): .
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 * * Release 0 Modification 1 and Release 1 * * Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Increase in cpu usage and storage usage * * over time when an application uses * * message marking and/or message * * selection (for example, MDBs running * * under WSAS). * **************************************************************** * RECOMMENDATION: * **************************************************************** When an application browsing a queue checks if a message has been marked, or if a message has already been evaluated against a selector, CSQMMTPR attempts to locate an MTME control block for the message. If no MTME exists, a new one is created for that message. It is possible for another task to delete the same message shortly before the check occurs, and cause any existing MTME to be deleted. When the original task performs the check, this results in a new MTME being created, and because the message is now deleted the new MTME will never be deleted. Over time, the number of such orphaned MTMEs can increase, leading to increased storage usage, and a high cpu cost when MTME synonym chains are searched.
Problem conclusion
CSQMMTPR is changed to no longer create an MTME for a message when checking if that message has been marked or evaluated against the selector. 010Y 100Y CSQMMTPR
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PM98668
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
2013-10-08
Closed date
2013-10-31
Last modified date
2014-02-24
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI12025 UI12026
Modules/Macros
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:
24 February 2014