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PI47257: FFDC is produced for a NullPointerException in com.ibm.ws.tcpcha nnel.internal.SocketRWChannelSelector.updateSelector.

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APAR status

  • Closed as program error.

Error description

  • Very rarely, an FFDC is produced indicating a
    NullPointerException similar to the following:
    
    >Exception = java.lang.NullPointerException
    >Source =
    com.ibm.ws.tcpchannel.internal.SocketRWChannelSelector
    >probeid = 254
    >Stack Dump = java.lang.NullPointerException
    > at
    com.ibm.ws.tcpchannel.internal.SocketRWChannelSelector.updat
    eSelector(SocketRWChannelSelector.java:193)
    > at
    com.ibm.ws.tcpchannel.internal.ChannelSelector.run(ChannelSe
    lector.java:227)
    > at java.lang.Thread.run(Thread.java:804)
    
    The error itself is harmless other than the appearance of
    the FFDC.  It is produced because the ChannelSelector thread
    is processing connections that may have been closed by
    another thread, and there is a timing window where the
    ChannelSelector, while attempting to write an event trace,
    will dereference a null field obtained from a closed
    connection.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  IBM WebSphere Application Server Version    *
    *                  7.0, 8.0 and 8.5.5 Full Profile             *
    ****************************************************************
    * PROBLEM DESCRIPTION: A First Failure Data Capture (FFDC)     *
    *                      is produced for a                       *
    *                      java.lang.NullPointerException in the   *
    *                      TCP Channel                             *
    *                      SocketRWChannelSelector.updateSelector  *
    *                      method                                  *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Very rarely, an FFDC is produced indicating a
    java.lang.NullPointerException similar to the following:
    >Exception = java.lang.NullPointerException
    >Source =
    com.ibm.ws.tcpchannel.internal.SocketRWChannelSelector
    >probeid = 254
    >Stack Dump = java.lang.NullPointerException
    > at
    com.ibm.ws.tcpchannel.internal.SocketRWChannelSelector.updateSel
    ector(SocketRWChannelSelector.java:193)
    > at
    com.ibm.ws.tcpchannel.internal.ChannelSelector.run(ChannelSelect
    or.java:227)
    > at java.lang.Thread.run(Thread.java:804)
    The error itself is harmless other than the appearance of the
    FFDC.  It is produced because the ChannelSelector thread is
    processing connections that may have been closed by another
    thread, and there is a timing window where the
    ChannelSelector, while attempting to write an event trace,
    will dereference a null field obtained from a closed
    connection.
    

Problem conclusion

  • The TCP Channel was modified to avoid the NullPointerException.
    
    The fix for this APAR is currently targeted for inclusion in
    Java 8 SR2, Java 7.1 SR3 FP20, Java 7 SR9 FP20, Java 6.1 SR8
    FP15, and Java 6 SR16 FP15.
    
    IBM WebSphere Application Server Version 8.5.5.9, 8.0.0.12, and
    7.0.0.41 will include one of the above mentioned Java
    releases.
    
    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

    PI47257

  • Reported component name

    WEBSPHERE APP S

  • Reported component ID

    5724J0800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-08-20

  • Closed date

    2015-10-15

  • Last modified date

    2015-10-15

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

    PI46433

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

Fix information

  • Fixed component name

    WEBSPHERE APP S

  • Fixed component ID

    5724J0800

Applicable component levels

  • R700 PSY

       UP

  • R800 PSY

       UP

  • R850 PSY

       UP



Document information

More support for: WebSphere Application Server
General

Software version: 850

Reference #: PI47257

Modified date: 15 October 2015