A fix is available
APAR status
Closed as program error.
Error description
A client channel (running mqmonntp.exe) is browsing messages on a queue. The messages were put on the queue before MQ v7. Routine rstCheckForOneMessage in CSECT CMQXRSTF / LMOD CSQXRCTL was continually trying to retrieve them. The problem is that the MQGET processing keeps returning MQRC_TRUNCATED_MSG_FAILED with DataLength set to the length of the message, x561, although a large enough buffer has been supplied, x561. The problem was in CSQIMGE5 when processing a message put before MQ V7 (i.e. in an IRH2) which contains an RFH2 (len_moved is not updated with the length of the RFH2 put into the buffer by CSQMHDRS). The loop occurs when using a client with SHARECNV > 0 to browse the queue in question. . Additional Symptom(s) Search Keyword(s): MQMON MQMON session
Local fix
If you want to delete the message from the queue, a couple of options are: 1) CLEAR QLOCAL (this will remove all messages on the queue) 2) Have a program, e.g. a batch job, do an MQGET for the MSGID of the specific message with MQGMO_ACCEPT_TRUNCATED_MSG (otherwise the MQGET will always fail with MQRC_TRUNCATED_MSG_FAILED no matter how big the buffer supplied).
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 8 * * Release 0 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Client application getting a message * * with message properties in a * * message handle can cause the CHIN * * address space to loop resulting * * in high CPU usage. * **************************************************************** * RECOMMENDATION: * **************************************************************** Messages created in pre-V7 queue managers that have remained in queues after migration to V8 and they have RFH2 headers can cause the CHIN loop when a client application gets the message with option MQGMO_PROPERTIES_IN_HANDLE or MQGMO_PROPERTIES_AS_Q_DEF and the queue has attribute PROPCTL(ALL).
Problem conclusion
CSQIMGE5 has been updated to process pre-V7 messages with RFH2 correctly without causing the CHIN to loop. 000Y CSQIMGE5
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI74146
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
2016-12-22
Closed date
2017-05-18
Last modified date
2017-08-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
PI81299 UI47357
Modules/Macros
CSQIMGE5
Fix information
Fixed component name
WMQ Z/OS 8
Fixed component ID
5655W9700
Applicable component levels
R000 PSY UI47357
UP17/07/25 P F707 ¢
Fix is available
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Document Information
Modified date:
02 August 2017