PM23556: LARGE CLIENTDELEGATE INSTANCES LEADING TO HEAP EXHAUSTION

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Error Message: Customer reports large instances of
    ClientDelegate and IOR objects persisting on heap even after the
    Services(EJBs) been evacuated. Issue is seen on 142 SR13 FP4.
    
    Large no. of instances of following objects was found during
    HeapDump Analysis:
    a com.ibm.CORBA.iiop.ClientDelegate
    b com.ibm.CORBA.iiop.ObjectKey
    c)com.ibm.rmi.IOR
    .
    Stack Trace: N/A
    .
    In Customer Scenario the two largest collections of objects in
    on heap dump were the a)SessionManager and b) SelectionManager.
    SessionManager was collecting sessions for a common EJB or
    server. The SelectionManager cached the IOR (indirect object
    reference) for RMI calls.
    
    Analysis of heapdumps taken over the issue revealed a possible
    leak in the following object graph:
    ------------------------------------------------------
    com.ibm.ws.util.ThreadPool$Worker @ 0xa50aaaf0  ORB.thread.pool
    : 393 JNI Global, Thread
    <HAT>00- <Java Local> com.ibm.ws.orb.WSExtendedServerDelegate @
    0x712a8378
    <HAT>00  '- clientSubcontractMappingFactory
    com.ibm.CORBA.iiop.ServerDelegate$ClientSubcontractMappingFactor
    y @ 0x712bbff0
    <HAT>00     '- cache
    com.ibm.jtc.orb.map.CacheFactories$Soft$FutureCacheImpl @
    0x71642518
    <HAT>00        '- map java.util.HashMap @ 0x71642530
    <HAT>00           '- elementData
    java.util.HashMap$Entry<OSB>262144<CSB> @ 0x83000008
    <HAT>00              <HAT>00- <OSB>41042<CSB>
    java.util.HashMap$Entry @ 0x9a304648
    ............
    
    - <Java Local> com.ibm.CORBA.iiop.ORB @ 0x712a2010
    <HAT>00  <HAT>00- fWLMPlugin com.ibm.ws.wlm.client.WLMClient @
    0x712a2350
    <HAT>00  <HAT>00  '- impl
    com.ibm.ws.cluster.router.selection.WLMClientForCommonRouterImpl
    @ 0x712a3718
    <HAT>00  <HAT>00     '- selectionMgr
    com.ibm.ws.cluster.router.selection.SelectionManager @
    0x71af5e90
    <HAT>00  <HAT>00        '- proxies java.util.WeakHashMap @
    0x71afc218
    <HAT>00  <HAT>00           '- elementData
    java.util.WeakHashMap$Entry<OSB>376832<CSB> @ 0x85800148
    ............
    

Local fix

Problem summary

  • The "Soft" held ClientDelegate references in ORB's
    ServerDelegate led to a bloated memory footprint.
    

Problem conclusion

  • This defect will be fixed in:
    1.4.2 SR13 FP8
    .
    The ClientDelegate cache in ServerDelegate  has been "Weak"end
    taking care to not loose functionality.
    .
    To obtain the fix:
    Install build 20101105 or later
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM23556

  • Reported component name

    JAVA(1.3/1.4 CO

  • Reported component ID

    5648C9800

  • Reported release

    42A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-09-30

  • Closed date

    2010-11-16

  • Last modified date

    2011-01-05

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    PM23557 PM23558 PM23561

Fix information

  • Fixed component name

    JAVA(1.3/1.4 CO

  • Fixed component ID

    5648C9800

Applicable component levels

  • R42A PSN

       UP

  • R42L PSN

       UP

  • R42W PSN

       UP

  • R420 PSN

       UP



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Document information


More support for:

z/OS family

Software version:

1.4.2

Reference #:

PM23556

Modified date:

2011-01-05

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