Fixes are available
APAR status
Closed as program error.
Error description
There is a timing condition in the WebSphere MQ checkpoint code that can lead to the heads of empty message queues not being flushed to disk, and resulting in a damaged object after a crash recovery. Probe Id :- AQ123001 Component :- aqqLoadMsgHdr Major Errorcode :- arcE_OBJECT_DAMAGED MQM Function Stack zlaMainThread zlaProcessMessage zlaProcessMQIRequest zlaMQOPEN zsqMQOPEN kpiMQOPEN kqiOpenIt kqiOpenQueue apiLoadQueue aqmLoadQueue aqhLoadQueue aqhLoadMsgChain aqhLoadMsg aqqLoadMsgHdr xcsFFST Probe Id :- AQ060020 Component :- aqhLoadMsgChain Major Errorcode :- arcE_OBJECT_DAMAGED
Local fix
Problem summary
**************************************************************** USERS AFFECTED: This is a small timing window that could effect any customer using persistent messages of differing priorities, who suffers from a queue manager crash. Platforms affected: All Distributed (iSeries, all Unix and Windows) **************************************************************** PROBLEM SUMMARY: There is very small timing window where the queue manager does not flush the head of an empty message chain to disk during checkpoint. If this problem is followed by a queue manager crash then this can lead the queue manager to erroneously believe there are additional messages on the queue, and can result in the queue being detected as damaged. This bug has existed in the code since 5.3 GA. The fact that the problem has only just been exposed (November 2009) gives an indication as to how unlikely the circumstances are in which the problem can arise.
Problem conclusion
The checkpoint code was changed to flush the queue header when all of the messages on the queue had been put since the start checkpoint log record was written, but one or more of the message chains is now empty when it was not empty when the queue was last checkpointed. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: v6.0 Platform Fix Pack 6.0.2.9 -------- -------------------- Windows U200313 AIX U828012 HP-UX (PA-RISC) U827381 HP-UX (Itanium) U827383 Solaris (SPARC) U827693 Solaris (x86-64) U828055 iSeries tbc_p600_0_2_9 Linux (x86) U827380 Linux (x86-64) U827694 Linux (zSeries) U827590 Linux (Power) U827382 Linux (s390x) U827695 v7.0 Platform Fix Pack 7.0.1.2 -------- -------------------- Windows U200316 AIX U829807 HP-UX (PA-RISC) U829678 HP-UX (Itanium) U829681 Solaris (SPARC) U829806 Solaris (x86-64) U829680 iSeries tbc_p700_0_1_2 Linux (x86) U829677 Linux (x86-64) U829676 Linux (zSeries) U829682 Linux (Power) U829679 The latest available maintenance can be obtained from 'WebSphere MQ Recommended Fixes' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037 If the maintenance level is not yet available, information on its planned availability can be found in 'WebSphere MQ Planned Maintenance Release Dates' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309 ---------------------------------------------------------------
Temporary fix
Comments
APAR Information
APAR number
IZ64138
Reported component name
WMQ LIN X86 V6
Reported component ID
5724H7204
Reported release
601
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-10-30
Closed date
2009-11-24
Last modified date
2009-12-17
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
WMQ LIN X86 V6
Fixed component ID
5724H7204
Applicable component levels
R601 PSY
UP
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Document Information
Modified date:
31 March 2023