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IC85932: WMQ CLASSES FOR JMS. WHEN SENDING LARGE MESSAGES USING RLE COMPRESSION, MESSAGE ARRIVES WITH SOME CORRUPTED CHARACTERS

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APAR status

  • Closed as program error.

Error description

  • When using a WebSphere MQ v7.5 classes for JMS application to
    send large JMS messages over a channel that uses RLE
    compression, the message arrives uncompressed but with some
    corrupted characters.
    
    For example, the original message snippet was :
    
    <xyz>true
    
    but the application received message is:
    
    _xyz>true
    
    Note that the first less-than symbol '<' has been replaced with
    underscore symbol '_'.
    

Local fix

  • None <br/>
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    All users of WebSphere MQ classes for Java/JMS applications
    that make use of RLE Message Compression when receiving
    messages.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM SUMMARY:
    When a large message (>32kB) was received that has been
    compressed using the RLE algorithm, it was possible that one
    or more bytes of the data received did not match the data
    originally compressed. The corrupted byte(s) were located at the
    boundary of the 32kB message transmission segment size of the
    data received by the WebSphere MQ classes for Java/JMS
    application.
    
    The problem occurred when a sequence of data has been compressed
    and required decompression. At the end of this decompression,
    there may have been one remaining byte left in the compressed
    buffer of the message segment received from the queue manager.
    This last remaining byte was not being copied into the
    decompressed buffer resulting in the previously received
    transmission segment's final byte being used in the received
    message data instead.
    

Problem conclusion

  • This code change associated with this APAR solves the problem by
    ensuring that if there is one byte left in the buffer after a
    data sequence has been received, then it is written to the
    decompressed buffer.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Platform           v7.5
    --------           --------------------
    Multiplatforms     7.5.0.1
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC85932

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7241

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-08-16

  • Closed date

    2012-08-30

  • Last modified date

    2012-08-30

  • 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

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7241

Applicable component levels

  • R750 PSY

       UP

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Document Information

Modified date:
19 September 2021