Fixes are available
APAR status
Closed as program error.
Error description
In an agent with multiple applications servicing an individual queue, one particular application ends up in an MQGET call for an extended period of time when MQGMO_WAIT is specified. This results in the application seemingly hanging until the MQGET call returns.
Local fix
Not Applicable
Problem summary
**************************************************************** USERS AFFECTED: Anyone using MQ with multiple applications doing MQGET with MQGMO_WAIT specified on a queue. Platforms affected: All Distributed (iSeries, all Unix and Windows) **************************************************************** PROBLEM SUMMARY: The problem was caused by multiple agent threads competing for messages on a queue. A particular thread was consistently failing to retrieve a message from the queue prior to other threads obtaining the message. However, the timer used for the get with wait call was always being reset to 0 every time the thread was notified that a new message was ready for retrieval. As such, it was caught in an endless loop until it either successfully retrieved a message from the queue prior to other threads waiting, or a suitable amount of time longer than the wait interval passed without any new messages appearing on the queue.
Problem conclusion
The solution was to avoid resetting the timer after each failed attempt to retrieve a message. As such, the wait interval was now able to expire and the MQGET could then return. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: v6.0 Platform Fix Pack 6.0.2.3 -------- -------------------- Windows U200279 AIX U811346 HP-UX (PA-RISC) U811630 HP-UX (Itanium) U811631 Solaris (SPARC) U811632 Solaris (x86-64) U811633 iSeries SI27288 Linux (x86) U811634 Linux (x86-64) U811635 Linux (zSeries) U811636 Linux (Power) U811637 Linux (s390x) U811638 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
IY97558
Reported component name
WMQ LIN X86 V6
Reported component ID
5724H7204
Reported release
600
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2007-04-18
Closed date
2007-05-21
Last modified date
2007-07-27
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
R600 PSY
UP
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Document Information
Modified date:
31 March 2023