Fixes are available
APAR status
Closed as program error.
Error description
If connection sharing is in use, a hang occurs if an existing connection is being closed when a new connection attempt is being made. Since the thread used to receive data is now closed, the thread waiting for data, therefore, waits indefinitely. Here is a java stack that indicates a problem: "Thread-382" (TID:0x39650A00, sys_thread_t:0x395BEFD0, state:CW, native ID:0x00AD10F5) prio=5 at java/lang/Object.wait(Native Method) at java/lang/Object.wait(Object.java:199) at com/ibm/mq/jmqi/remote/internal/RemoteHconn.receiveAsyncTsh (RemoteHconn.java:1912) at com/ibm/mq/jmqi/remote/internal/RemoteHconn.receiveTSH (RemoteHconn.java:1176) at com/ibm/mq/jmqi/remote/internal/system/RemoteConnection .addHconn(RemoteConnection.java:891) at com/ibm/mq/jmqi/remote/internal/system/RemoteConnectionPool .getConnection(RemoteConnectionPool.java:495(Compiled Code)) "Thread-232" (TID:0x3562DB00, sys_thread_t:0x356797E8, state:CW, native ID:0x007DC0C7) prio=5 at java/lang/Object.wait(Native Method) at java/lang/Object.wait(Object.java:199(Compiled Code)) at com/ibm/mq/jmqi/remote/internal/system/RemoteConnection .sendTSH(RemoteConnection.java:2185(Compiled Code)) at com/ibm/mq/jmqi/remote/internal/system/RemoteConnection .addHconn(RemoteConnection.java:876(Compiled Code)) at com/ibm/mq/jmqi/remote/internal/system/RemoteConnectionPool .getConnection(RemoteConnectionPool.java:490(Compiled Code)) Another symptom which may also be observed in the logs is the following ConcurrentModificationException stack trace: java.util.ConcurrentModificationException at java.util.LinkedList$ListItr.checkForComodification(LinkedL ist.java:617) at java.util.LinkedList$ListItr.next(LinkedList.java:552) at com.ibm.mq.jmqi.remote.internal.system.RemoteConnectionPool .getConnection(RemoteConnectionPool.java:173)
Local fix
Disable connection sharing. The following line should be used to set the property: m_mqProperties.put(MQC.SHARING_CONVERSATIONS_PROPERTY, new Integer("1")); where m_mqProperties is a Hashtable used when creating the MQQueueManager object.
Problem summary
**************************************************************** USERS AFFECTED: This issue affects users of WebSphere MQ Java/Java Message Service (JMS) based applications who utilise connection sharing Platforms affected: All Distributed (iSeries, all Unix and Windows) +Java **************************************************************** PROBLEM SUMMARY: A small timing window in the WebSphere MQ Java/JMS client allowed a connection to be identified as suitable for sharing by one thread, but then be closed by another thread. The code was modified to removing this timing window, and also prevent the ConcurrentModificationException exception from occurring.
Problem conclusion
The WebSphere MQ Java/JMS client has been updated to remove the timing window. | MDVPARTL 7.0.1-WS-MQ-Windows-FP0001 | | MDVPARTL 7.0.1-WS-MQ-SolarisX64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-SolarisSparc64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-LinuxX64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-LinuxS390X-FP0001 | | MDVPARTL 7.0.1-WS-MQ-LinuxPPC64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-LinuxIA32-FP0001 | | MDVPARTL 7.0.1-WS-MQ-HpuxPaRISC64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-HpuxIA64-FP0001 | | MDVPARTL 7.0.1-WS-MQ-AixPPC64-FP0001 | --------------------------------------------------------------- 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
IZ65557
Reported component name
WMQ AIX V7
Reported component ID
5724H7221
Reported release
701
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2009-11-19
Closed date
2009-12-23
Last modified date
2010-04-08
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 AIX V7
Fixed component ID
5724H7221
Applicable component levels
R701 PSY
UP
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0.1"}]
Document Information
Modified date:
06 October 2021