JR42522: BusinessDataAliasCache performance and memory leak fix for IBM Business Process Manager

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APAR status

  • Closed as program error.

Error description

  • The inital load of the BusinessDataAliasCache, which is an
    internal cache that is associated with portal queries, scales
    poorly as the number of named snapshots in the database
    increases. The performance problem is also associated with
    large amounts of memory being consumed and heavy load on the
    database.
    .
    Heap Analyzer shows 90% of memory with the branch manager.
    .
    One instance of
    "com.lombardisoftware.server.ejb.persistence.versioning.BranchMa
    nager"
    loaded by "com.ibm.oti.vm.BootstrapClassLoader @ 0x40f91a48"
    occupies
    1,944,715,592 (90.52%) bytes. The memory is accumulated in one
    instance
    of "java.util.concurrent.ConcurrentHashMap$Segment[]" loaded by
    "com.ibm.oti.vm.BootstrapClassLoader @ 0x40f91a48".
    

Local fix

  • n/a
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Users of BPM Express, BPM Standard and BPM  *
    *                  Advanced                                    *
    ****************************************************************
    * PROBLEM DESCRIPTION: The first login to the portal           *
    *                      triggers the initial load of the        *
    *                      cache and can take a long time. It      *
    *                      sometimes results in page time outs     *
    *                      and hung thread stack traces in the     *
    *                      server log files. During this initial   *
    *                      load, there is excessive load on the    *
    *                      database. Users will see stack traces   *
    *                      with content like:                      *
    *                      at                                      *
    *                      com/lombardisoftware/server/ejb/psapi/B *
    *                      usinessDataAliasesCache.getBusinessData *
    *                      Aliases(BusinessDataAliasesCache.java:4 *
    *                      5)                                      *
    *                      at                                      *
    *                      com/lombardisoftware/servlet/util/Cache *
    *                      Manager.init(CacheManager.java:112)     *
    *                      at                                      *
    *                      com/ibm/ws/webcontainer/servlet/Servlet *
    *                      Wrapper.init(ServletWrapper.java:358)   *
    *                      at                                      *
    *                      com/ibm/ws/webcontainer/servlet/Servlet *
    *                      WrapperImpl.init(ServletWrapperImpl.jav *
    *                      a:169)                                  *
    *                      at                                      *
    *                      com/ibm/ws/webcontainer/servlet/Servlet *
    *                      Wrapper.initialize(ServletWrapper.java: *
    *                      1809                                    *
    ****************************************************************
    * RECOMMENDATION:  Recommended IFIX                            *
    ****************************************************************
    The first login to the portal
    triggers the initial load of the
    cache and can take a long time. It
    sometimes results in page time outs
    and hung thread stack traces in the
    server log files. During this initial
    load, there is excessive load on the
    database. Users will see stack traces
    with content like:
    at
    com/lombardisoftware/server/ejb/psapi/B
    usinessDataAliasesCache.getBusinessData
    Aliases(BusinessDataAliasesCache.java:4
    5)
    at
    com/lombardisoftware/servlet/util/Cache
    Manager.init(CacheManager.java:112)
    at
    com/ibm/ws/webcontainer/servlet/Servlet
    Wrapper.init(ServletWrapper.java:358)
    at
    com/ibm/ws/webcontainer/servlet/Servlet
    WrapperImpl.init(ServletWrapperImpl.jav
    a:169)
    at
    com/ibm/ws/webcontainer/servlet/Servlet
    Wrapper.initialize(ServletWrapper.java:
    1809
    On runtime servers with many deployed snapshots, large amounts
    of memory might be consumed, which sometimes leads to out of
    memory errors. Heap dump analysis points to a class named
    BranchManager as a leak suspect.
    

Problem conclusion

  • The fix:
    The algorithm for loading and incrementally updating this
    cache has been optimized to dramatically reduce the number of
    queries to the database and the server time needed to process
    the results.
    The fix also addresses the memory leak by avoiding the code
    path that exposed the leak and by putting a configurable bound
    on the number of entries in the BranchManager cache.
    
    On systems with very large number of snapshots and versions of
    business process definitions (BPDs) (especially Process
    Center), the first login to the portal after a server start
    might still have a delay.
    Details available here:
    http://www-304.ibm.com/support/docview.wss?uid=swg27025011
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    
    The interim fix is available in fix central for the following
    versions:
    7.5.0.1
    7.5.1
    It is also fixed in future fix packs and releases.
    
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    
    In version 7.5.0 Fix Pack 1 (7.5.0.1), this fix is available
    as a part of the JR42581 ifix package.
    JR42581 can be downloaded from Fix Central:
    http://www-933.ibm.com/support/fixcentral/swg/quickorder?parent=
    ibm~WebSphere&product=ibm/WebSphere/IBM+Business+Process+Manager
    +Advanced&release=7.5.0.1&platform=All&function=fixId&fixids=7.5
    .0.1-WS-BPM-IFJR42581&includeSupersedes=0&source=fc
    The installation instruction can be downloaded along with
    JR42581 ifix file.
    
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    
    Install/Dependency information on 7.5.1:
    
    Is available in the readme.txt on FixCentral.
    When the user goes to the download files page in FixCentral the
    readme will be available with the fix package as a seperate
    download.
    
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    THIS FIX REQUIRES POST INSTALL XML CONFIGURATION CHANGES.
    PLEASE CONSULT README FOR THE SAME.
    

Temporary fix

Comments

APAR Information

  • APAR number

    JR42522

  • Reported component name

    BPM ADVANCED

  • Reported component ID

    5725C9400

  • Reported release

    751

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-04-12

  • Closed date

    2012-05-24

  • Last modified date

    2014-06-23

  • 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

    BPM ADVANCED

  • Fixed component ID

    5725C9400

Applicable component levels

  • R750 PSY

       UP



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Document information


More support for:

IBM Business Process Manager Advanced

Software version:

7.5.1

Reference #:

JR42522

Modified date:

2014-06-23

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