Fixes are available
APAR status
Closed as program error.
Error description
A connection leak is seen following failover and reconnection to a queue manager if subscriptions are used from the resource adapter, and clone support is enabled. A trace shows an error with the stack: 17:22:46:18.701.09 0021 @848c58 c.i.m.c.w.v.jms.internal.MQBrokerSubscriptionList :::----+----+-- { getSubscription(String,MQSession) [JMS:::JMS\\\u 003#AnsExpiredMessageListener] [c.i.m.c.wmq.v6.jms.internal.MQSession@153b9ee] 17:22:46:18.701.0A 0021 static MQBrokerSubscriptionList :::----+----+--- d unspecified method subscription JMS:#visw_jMDBAnsExpire.jar#AnsExpiredMessageListener already in use <null> 17:22:46:18.701.0B 0021 @848c58 c.i.m.c.w.v.jms.internal.MQBrokerSubscriptionList :::----+----+--- ! getSubscription(String,MQSession)<throwIndex 1>, MQJMS3023 [javax.jms.JMSException] 17:22:46:18.701.0C 0021 @848c58 c.i.m.c.w.v.jms.internal.MQBrokerSubscriptionList :::----+----+--- X getSubscription(String,MQSession) 17:22:46:18.701.0C 0021 MQJMS3023 [javax.jms.JMSException] at: 17:22:46:18.701.0C 0021 com.ibm.msg.client.wmq.v6.jms.internal .MQBrokerSubscriptionList.getSubscription (MQBrokerSubscriptionList.java:102) 17:22:46:18.701.0C 0021 com.ibm.msg.client.wmq.v6.jms.internal. MQBrokerSubscriptionEngine.openDurableSubscription (MQBrokerSubscriptionEngine.java:845) A new connection will be created after each reconnectionRetryInterval. The number of connections created will be equal to the reconnectionRetryCount. Eventually the reconnectionRetryCount will be reached. The mqjms.log will report [JMSCCThreadPoolWorker-10] JCAMessageBuilder Failed to reconnect one or more MDBs after a connection failure. EXPLANATION: The connection supplying one or more MDBs failed, and the resource adapter was not able to reconnect within the number of attempts specified by the reconnectionRetryCount property.
Local fix
Once the reconnectionRetryCount has been exceeded, the MDB(s) will need to be restarted manually
Problem summary
**************************************************************** USERS AFFECTED: This issue affects all WebSphere MQ J2EE Connector Architecture (JCA) resource adapter users, as well as WebSphere Application Server Version 7 users, whose applications create subscriptions with clone support. 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, a reconnection helper thread was spawned to reestablish the connection. This thread found what it thought was another valid connection to rebuild the subscription. This connection was also broken, so the attempt to subscribe failed. This broken connection meant we spawned another reconnection helper thread to rebuild this other broken connection. Both of these reconnection helper threads then attempted to rebuild the subscription. One succeeded, and the other continued to try to resubscribe. With each re-subscription attempt, the reconnection helper thread created a new connection, which was not closed. As clone support was enabled, each attempt failed, as we were already subscribed. This reconnection helper thread then waited for the reconnectionRetryInterval to try again. After this interval, a new connection was created, and the subscription failed as we were already subscribed. This pattern continued a number of times up to the reconnectionRetryCount, causing a number of connection to be created which were then not closed.
Problem conclusion
If a connection is created to rebuild a subscription, and this attempt fails, the connection is now closed. If a re-subscription fails because we are already subscribed, we do not continue to try to resubscribe. The connection leak following queue manager fail-over no longer occurs. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: 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
IC65087
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
2009-12-10
Closed date
2009-12-23
Last modified date
2009-12-23
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