IBM Support

PH40879: Server startup hang caused by plugin-cfg.xml generation

Subscribe to this APAR

By subscribing, you receive periodic emails alerting you to the status of the APAR, along with a link to the fix after it becomes available. You can track this item individually or track all items by product.

Notify me when this APAR changes.

Notify me when an APAR for this component changes.

 

APAR status

  • Closed as program error.

Error description

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Users of WebSphere Liberty with restrictive *
    *                  maxThreads configurations                   *
    ****************************************************************
    * PROBLEM DESCRIPTION: Server startup can hang with            *
    *                      restrictive maxThreads configurations   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    A change was made in Liberty fixpack 21.0.0.7 to improve
    diagnostic tracing for hostname lookups. When the server thread
    count is restricted - for example with <executor
    maxThreads="6"/> - and a large number of apps are deployed, the
    hostname lookup code change can cause a deadlock during plugin-
    cfg.xml generation at server startup.
    
    A javacore for this problem will contain a stack like:
    
    3XMTHREADINFO      "Default Executor-thread-3"
    J9VMThread:0x00000000006E8900, omrthread_t:0x00007F5138005928,
    java/lang/Thread:0x00000007001E36E0, state:P, prio=5
    ...
    3XMCPUTIME               CPU usage total: 9.448750727 secs,
    current category="Application"
    3XMTHREADBLOCK     Parked on:
    java/util/concurrent/FutureTask@0x00000007334DA3D0 Owned by:
    <unknown>
    3XMHEAPALLOC             Heap bytes allocated since last GC
    cycle=4096 (0x1000)
    3XMTHREADINFO3           Java callstack:
    4XESTACKTRACE                at sun/misc/Unsafe.park(Native
    Method)
    4XESTACKTRACE                at
    java/util/concurrent/locks/LockSupport.parkNanos(LockSupport.jav
    a:226(Compiled Code))
    4XESTACKTRACE                at
    java/util/concurrent/FutureTask.awaitDone(FutureTask.java:437(Co
    mpiled Code))
    4XESTACKTRACE                at
    java/util/concurrent/FutureTask.get(FutureTask.java:215)
    4XESTACKTRACE                at
    com/ibm/wsspi/channelfw/utils/HostNameUtils.doPrivilegedWithTime
    outWarning(HostNameUtils.java:343)
    4XESTACKTRACE                at
    com/ibm/wsspi/channelfw/utils/HostNameUtils.tryResolveHostName(H
    ostNameUtils.java:230)
    4XESTACKTRACE                at
    com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.tryDetermine
    HostName(PluginGenerator.java:2069)
    4XESTACKTRACE                at
    com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.buildServerT
    ransportData(PluginGenerator.java:1379)
    4XESTACKTRACE                at
    com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.generateXML(
    PluginGenerator.java:487)
    5XESTACKTRACE                   (entered lock:
    com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator@0x0000000733
    4E1EB0, entry count: 1)
    4XESTACKTRACE                at
    com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean.ge
    neratePluginConfig(GeneratePluginConfigMBean.java:160)
    5XESTACKTRACE                   (entered lock:
    com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean@0x
    0000000701269D58, entry count: 1)
    4XESTACKTRACE                at
    com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean.ge
    neratePluginConfig(GeneratePluginConfigMBean.java:262)
    ...
    

Problem conclusion

  • Liberty has been updated to avoid this deadlock scenario. See
    https://github.com/OpenLiberty/open-liberty/issues/18530 for
    more information.
    
    The fix for this APAR is currently targeted for inclusion in fix
    pack 21.0.0.10.  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

    PH40879

  • Reported component name

    WAS LIBERTY COR

  • Reported component ID

    5725L2900

  • Reported release

    CD0

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2021-09-24

  • Closed date

    2021-09-24

  • Last modified date

    2021-11-11

  • 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

    WAS LIBERTY COR

  • Fixed component ID

    5725L2900

Applicable component levels

[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSD28V","label":"WebSphere Application Server Liberty Core"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"CD0"}]

Document Information

Modified date:
12 November 2021