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PI74952: CLASSLOADER LEAK CAUSED BY EJB TIMER THREAD

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APAR status

  • Closed as program error.

Error description

  • The classloader leak is caused by the
    "WebSphere_EJB_Timer_Service_WorkManager Thread ".
    The reference of EJB_Timer thread to CompoundClassLoader
    remained, so classloader leak might occur.
    
    com.ibm.ws.classloader.CompoundClassLoader @ 0x7010d8a10
       war:test-1_0-SNAPSHOT-DF01_war/test-1.0-SNAPSHOT-DF01.war
    '- moduleClassLoader
    com.ibm.ws.webbeans.services.ScannerServiceImpl @0x71cb48a50
       '- scannerService
    org.apache.webbeans.container.BeanManagerImpl @0x726ddf8e0
          '- beanMgrImpl
    com.ibm.ws.webbeans.services.IBMBeanManagerImpl @0x711403410
             '- value
    java.util.concurrent.ConcurrentHashMap$HashEntry @0x70110a8c0
                '- [0]
    java.util.concurrent.ConcurrentHashMap$HashEntry[1] @0x70c53c1d0
                   '- table
    java.util.concurrent.ConcurrentHashMap$Segment @0x70c53bfa0
                      '- [13]
    java.util.concurrent.ConcurrentHashMap$Segment[16] @ 0x70c53bf18
                         '- segments
    java.util.concurrent.ConcurrentHashMap@ 0x70c4ce340
                            '- cache
    my.test.class$BeanManagerCache @0x70c4c1bb0
                               '- INSTANCE class
    my.test.class$BeanManagerCache @0x700b6b018
                                  '-
    com.ibm.ws.classloader.CompoundClassLoader @ 0x700d7ee68
    
       war:test-1_0-SNAPSHOT-DF01_war/test-1.0-SNAPSHOT-DF01.war
                                     |- contextClassLoader
    com.ibm.ws.asynchbeans.am.AlarmManagerThread @ 0x710739108
    
       WebSphere_EJB_Timer_Service_WorkManager:AlarmManager Thread
                                     |- contextClassLoader
    java.lang.Thread@ 0x710739190  Alarms per second thread for
    
       WebSphere_EJB_Timer_Service_WorkManager Thread
                                     |- <classloader>,
    <classLoader> class
    my.test.second.class2 @ 0x700acc720
                                     |  '- <class>
    my.test.second.class2 @ 0x70c95d110
                                     |     '- value
    java.lang.ThreadLocal$ThreadLocalMap$Entry @ 0x70c969f78
                                     |        '- [237]
    java.lang.ThreadLocal$ThreadLocalMap$Entry[256] @ 0x70c5a02d0
                                     |           '- table
    java.lang.ThreadLocal$ThreadLocalMap @ 0x700e170c0
                                     |              '- threadLocals
    com.ibm.ws.util.ThreadPool$Worker @ 0x700e14508  server.startup
    : 1Thread
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server                                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: Class loader leak when scheduled        *
    *                      task/timer is read from the database    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Application class loader can be left on the thread that
    deserializes a scheduled tasks or timer from the database.
    This can prevent garbage collection of application classes
    once they are no longer needed, for example, because the
    application is stopped or restarted.
    

Problem conclusion

  • Code has been corrected to remove the application class loader
    from the thread.
    
    The fix for this APAR is currently targeted for inclusion in
    fix packs 8.5.5.12 and 9.0.0.4.  Please refer to the
    Recommended Updates page for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI74952

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-01-13

  • Closed date

    2017-04-12

  • Last modified date

    2017-04-12

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R850 PSY

       UP

  • R900 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"850","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
19 October 2021