A fix is available
APAR status
Closed as program error.
Error description
With 64 bit JVMs, an MQException with MQRC 2012 is thrown, seemingly randomly, when a transaction is committed: com.ibm.mq.MQException: MQJE001: Completion Code 2, Reason 2012 at com.ibm.mq.MQQueueManager.commit(MQQueueManager.java:2220) at com.ibm.mq.jms.MQSession.commitQ(MQSession.java:3779) at com.ibm.mq.jms.MQQueueSession.commit(MQQueueSession.java:154) at com.ibm.ejs.jms.JMSManagedSession$JMSLocalTransaction.commit(JMS ManagedSession.java:1201) at com.ibm.ejs.j2c.LocalTransactionWrapper.commit(LocalTransactionW rapper.java:259) The cause of the problem could result in other symptoms that have not yet been observed.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V7.0 * * * **************************************************************** * PROBLEM DESCRIPTION: MQException MQRC 2012 thrown at * * transaction commit. There could be * * other symptoms of this problem that * * are not yet known. * * * **************************************************************** * RECOMMENDATION: * **************************************************************** On 64 bit JVMs, the Java Object.hashcode() method cannot return a unique int for every Object. Traditionally hashcode is based on the memory address of the Object itself; there are more addresses with 64 bit than MAX_INT (32 bit signed integer) can address. Internally the WMQ JMS Provider relied on the uniqueness of hashcode to identify an internal connector (the JMS Session pools) to J2C. If two different connectors had the same identifier, when one is cleaned up, the other that should still be active has some state removed. This can result in the exception described, but equally could result in some other, seemingly random, problem. It is very unlikely that two Objects would have the same hashcode, let alone two Objects used in a group of say 30 (the number of JMS Connections in the pool). On Z/OS, however, the implementation of hashcode frequently produces the same int for different Objects, making the likelihood of this problem occurring higher. The likelihood of hitting this problem is also increased when many JMS Connections are created and destroyed. This scenario is possible when there are many requests of Connections using different user aliases, so J2C must destroy one Connection to create another suitable Connection with the correct credentials if the J2C Connection pool is already full.
Problem conclusion
This APAR fixes the problem by generating unique IDs for each connector, and no longer relies on hashcode. APAR PK02879 is currently targeted for inclusion in Service Level (Fix Pack) 7.0.0.8 of WebSphere Application Server V7.0. Please refer to URL: //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970 for Fix Pack availability.
Temporary fix
Comments
APAR Information
APAR number
PM02879
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
YesSpecatt / CST
Submitted date
2009-12-05
Closed date
2009-12-08
Last modified date
2010-01-11
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK52698
Modules/Macros
BBGBOA BBGUBINF BBORBACB BBORTFTE BBOUBINF BBOZ3446 BBO00772 BBO00798 BBO00801 BBO01062 BBO02121 BBO03574 BBO06919 BBO09142 BBO09341 BBO09390 BBO09391 BBO09405 BBO09406 BBO09504 BBO09958 BBO09990 BBO10127 BBO10128 BBO10142 BBO10143 BBO10188 BBO10189 BBO10241 BBO10516 BBO10517 BBO10521 BBO10524 BBO10525 BBO10529 BBO10533 BBO10538 BBO10540 BBO10541 BBO10542 BBO10543 BBO10544 BBO10545 BBO10547 BBO10549 BBO10550 BBO10551 BBO10555 BBO10556 BBO10562 BBO10563 BBO10564 BBO10573 BBO10575 BBO10581 BBO10582 BBO10584 BBO10590 BBO10597 BBO10598 BBO10599 BBO10604 BBO10605 BBO10606 BBO10607 BBO10609 BBO10610 BBO10611 BBO16109 BBO16111 BBO16114 BBO16115 BBO16119 BBO16121 BBO16123 BBO16131 BBO16132 BBO16140 BBO16141 BBO16145 BBO16146 BBO16147 BBO16159 BBO16166 BBO16167 BBO16168 BBO16169 BBO16172 BBO16173 BBO16194 BBO16195 BBO16210 BBO16217 BBO16218 BBO16219 BBO16220 BBO16224 BBO16230 BBO16231 BBO16234 BBO16237 BBO16238 BBO16241 BBO16243 BBO16244 BBO16255 BBO16257 BBO16262 BBO16267 BBO16268 BBO16269 BBO16270
Fix information
Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500
Applicable component levels
R700 PSY UK52698
UP09/12/18 P F912
Fix is available
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Document Information
Modified date:
10 February 2022