Fixes are available
APAR status
Closed as program error.
Error description
Messages are not spread evenly between two cluster destinations despite the fact that all workload balancing attributes have been set equally. Upon further investigation, it is found that some of the messages are being redistributed to a remote queue manager in the cluster, even once they had arrived across a cluster channel.
Local fix
Problem summary
**************************************************************** USERS AFFECTED: Any users of WebSphere MQ using pipelined channels in a cluster. Platforms affected: All Distributed (iSeries, all Unix and Windows) **************************************************************** PROBLEM SUMMARY: During channel initialisation, a flag is set on the thread servicing the channel to indicate that it is servicing a cluster receiver channel. This flag is accessible by the workload balancing algorithm and allows it to verify whether messages are incoming from a remote destination. This knowledge is used to prevent messages from being routed to remote destinations if it has already come across a cluster channel, thus preventing messages from hopping across multiple locations in the cluster. However, this flag was not being set in the secondary thread of a pipelined channel, and as a result, the workload balancing routine was unaware of the fact that messages being processed had already arrived from a remote destination. This was then leading to messages being routed repeatedly around the cluster, leading to unexpected distributions of messages on each individual destination.
Problem conclusion
WebSphere MQ was modified to ensure that the secondary thread responsible for communications across the dual pipelined channel was initialised correctly to reflect the fact that it was servicing messages on a cluster receiver channel. As such, the workload balancing algorithm running in the pipelined thread is now successfully able to tell that the message has already arrived from a remote queue manager, and consequently, removes all remote destinations from its list of eligible destinations. This prevents messages routed over cluster channels from hopping between multiple queue managers in the cluster. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: v7.0 Platform Fix Pack 7.0.1.3 -------- -------------------- Windows tbc_p700_0_1_3 AIX tbc_p700_0_1_3 HP-UX (PA-RISC) tbc_p700_0_1_3 HP-UX (Itanium) tbc_p700_0_1_3 Solaris (SPARC) tbc_p700_0_1_3 Solaris (x86-64) tbc_p700_0_1_3 iSeries tbc_p700_0_1_3 Linux (x86) tbc_p700_0_1_3 Linux (x86-64) tbc_p700_0_1_3 Linux (zSeries) tbc_p700_0_1_3 Linux (Power) tbc_p700_0_1_3 v6.0 Platform Fix Pack 6.0.2.10 -------- -------------------- Windows U200318 AIX U832558 HP-UX (PA-RISC) U833084 HP-UX (Itanium) U833088 Solaris (SPARC) U833085 Solaris (x86-64) U832557 iSeries tbc_p600_0_2_10 Linux (x86) U832545 Linux (x86-64) U833083 Linux (zSeries) U833089 Linux (Power) U833087 Linux (s390x) U833086 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
IC65822
Reported component name
WMQ WINDOWS V7
Reported component ID
5724H7220
Reported release
701
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-01-26
Closed date
2010-02-24
Last modified date
2010-02-24
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
PM08381
Fix information
Fixed component name
WMQ WINDOWS V7
Fixed component ID
5724H7220
Applicable component levels
R701 PSY
UP
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Document Information
Modified date:
31 March 2023