Fixes are available
APAR status
Closed as program error.
Error description
Two instances of the same message are seen by an application running in JBoss when using the WebSphere MQ v7 Resource Adapter (RA). The duplicate messages are seen shortly after the queue manager fails over. The issue is seen when using two applications running in separate instances of an application server. One sends a message which the other picks up using a topic listener. Shortly after the queue manager in use has failed over to another queue manager running on a different server the receiving application receives a duplicate message. That is, it sees the same message twice. After a restart of the partition with the sending application, no further duplicate messages are seen.
Local fix
Problem summary
**************************************************************** USERS AFFECTED: This issue affect users of the WebSphere MQ v7 Resource Adapter connecting to a queue manager who restart their queue manager twice as part of a failover, or otherwise break a connection as it is being rebuilt. Platforms affected: All Distributed (iSeries, all Unix and Windows) +Java **************************************************************** PROBLEM SUMMARY: When a connection from the resource adapter to the queue manager was broken, the resource adapter created a reconnection helper thread to rebuild this connection and its associated consumer. If this new connection was broken after the connection was created but before the consumer was created, a new reconnection helper thread was created to reconnect what the resource adapter thought was a new broken connection. However, as the original reconnection helper thread treated this break in the connection as a failure to rebuild the connection, it would continue in its attempt to reconnect. This meant we could end up with two reconnection helper threads active for a connection, and so when they were both eventually successful in reconnecting, we would have two instances of a consumer, where before the break in the connection there was only one.
Problem conclusion
A broken connection when recreating a consumer now does not create a new reconnection helper thread, instead the original thread handles the reconnection. Only one reconnection helper thread can now be active for a consumer at a time. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: v7.0 Platform Fix Pack 7.0.1.3 -------- -------------------- Windows U200320 AIX U834987 HP-UX (PA-RISC) U834414 HP-UX (Itanium) U834413 Solaris (SPARC) U834986 Solaris (x86-64) U834210 iSeries tbc_p700_0_1_3 Linux (x86) U834415 Linux (x86-64) U834985 Linux (zSeries) U834412 Linux (Power) U835662 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
IC66603
Reported component name
WMQ WINDOWS V7
Reported component ID
5724H7220
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-02-23
Closed date
2010-04-28
Last modified date
2010-04-28
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 WINDOWS V7
Fixed component ID
5724H7220
Applicable component levels
R700 PSY
UP
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Document Information
Modified date:
31 March 2023