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PI20987: Deadlocks can occur in the logging infrastructure.

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APAR status

  • Closed as program error.

Error description

  • The logging code can get into a deadlock.
    
    Deadlock detected !!!
    ---------------------
    Thread "WXS : 2: XSDistributedCommand"
    is waiting for:
    com/ibm/ejs/ras/SystemOutStream
    which is owned by:
    Thread "WXS : 18: XSDistributedCommand"
    which is waiting for:
    com/ibm/ws/bootstrap/WsLogManager
    which is owned by:
    Thread "WXS : 2: XSDistributedCommand" (0x0000000002E9C600)
    
    
    "WXS : 2: XSDistributedCommand"
    Blocked on: com/ibm/ejs/ras/SystemOutStream Owned by: "WXS : 18:
    XSDistributedCommand"
    Java callstack:
    at
    com/ibm/ejs/ras/SystemOutStream.processEvent(SystemOutStream.jav
    a:291)
    at
    com/ibm/ws/logging/WsHandlerWrapper.publish(WsHandlerWrapper.jav
    a:43)
    at java/util/logging/Logger.log(Logger.java:621)
    at
    com/ibm/ws/logging/WsLogger.deliverOrBuffer(WsLogger.java:279)
    at com/ibm/ws/logging/WsLogger.log(WsLogger.java:257)
    at com/ibm/ws/logging/WsLogger.logp(WsLogger.java:492)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.logMessage(WsLoggerConfi
    gurator.java:540)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.access$000(WsLoggerConfi
    gurator.java:62)
    at
    com/ibm/ws/logging/WsLoggerConfigurator$1.run(WsLoggerConfigurat
    or.java:194)
    at
    com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon
    troller.java:63)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.getExtensionPointLogging
    Configuration(WsLoggerConfigurator.java:179)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.getCurrentLoggingConfigu
    ration(WsLoggerConfigurator.java:300)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.getLoggerConfiguration(W
    sLoggerConfigurator.java:121)
    at
    com/ibm/ws/logging/WsLoggerConfigurator.configureLogger(WsLogger
    Configurator.java:346)
    at
    com/ibm/ws/logging/WsLoggerFactoryImpl.createWsLogger(WsLoggerFa
    ctoryImpl.java:80)
    at
    com/ibm/ws/bootstrap/RASDelegator.createWsLogger(RASDelegator.ja
    va:74)
    at
    com/ibm/ws/bootstrap/WsLogManager.getLogger(WsLogManager.java:21
    8)
    (entered lock:
    com/ibm/ws/bootstrap/WsLogManager@0x0000000680282830, entry
    count: 1)
    at
    java/util/logging/LogManager.demandLogger(LogManager.java:418)
    at java/util/logging/Logger.demandLogger(Logger.java:354)
    at java/util/logging/Logger.getLogger(Logger.java:401)
    at
    com/ibm/ws/ffdc/impl/WrappingFileOutputStream.<clinit>(WrappingF
    ileOutputStream.java:79)
    
    
    
    "WXS : 18: XSDistributedCommand"
    Blocked on: com/ibm/ws/bootstrap/WsLogManager Owned by: "WXS :
    2: XSDistributedCommand"
    Java callstack:
    at java/util/logging/LogManager.access$1500(LogManager.java:159)
    at
    java/util/logging/LogManager$RootLogger.getHandlers(LogManager.j
    ava:1445)
    at com/ibm/ejs/ras/Tr.logToWsHandlers(Tr.java:1689)
    at com/ibm/ejs/ras/Tr.systemOut(Tr.java:998)
    at
    com/ibm/ejs/ras/SystemOutStream.dispatchEvent(SystemOutStream.ja
    va:363)
    at com/ibm/ejs/ras/SystemStream.write(SystemStream.java:298)
    at
    com/ibm/ejs/ras/SystemOutStream.write(SystemOutStream.java:79)
    at sun/nio/cs/StreamEncoder.writeBytes(StreamEncoder.java:233)
    at
    sun/nio/cs/StreamEncoder.implFlushBuffer(StreamEncoder.java:303)
    at sun/nio/cs/StreamEncoder.implFlush(StreamEncoder.java:307)
    at sun/nio/cs/StreamEncoder.flush(StreamEncoder.java:153)
    (entered lock: java/io/OutputStreamWriter@0x0000000680340FE0,
    entry count: 1)
    at java/io/OutputStreamWriter.flush(OutputStreamWriter.java:289)
    (entered lock:
    com/ibm/ejs/ras/SystemOutStream@0x0000000680266668, entry count:
    1)
    at
    org/apache/log4j/helpers/QuietWriter.flush(QuietWriter.java:58)
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of WebSphere eXtreme Scale.       *
    ****************************************************************
    * PROBLEM DESCRIPTION: Underloaded threads can get into a      *
    *                      deadlock.                               *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    There was a problem identified in the WebSphere Application
    Server logging code that caused a deadlock under certain
    circumstances.  That problem was fixed under APAR PI21768.
    This APAR includes that code change in the eXtreme Scale code.
    

Problem conclusion

  • An interim fix is available for this APAR.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI20987

  • Reported component name

    WS EXTREME SCAL

  • Reported component ID

    5724X6702

  • Reported release

    860

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-06-30

  • Closed date

    2014-07-31

  • Last modified date

    2014-07-31

  • 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

    WS EXTREME SCAL

  • Fixed component ID

    5724X6702

Applicable component levels

  • R860 PSY

       UP

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Document Information

Modified date:
31 July 2014