IBM Support

IT30275: Update MQ Java SE common services component to use eight digit thread identifiers in trace

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APAR status

  • Closed as program error.

Error description

  • When capturing IBM MQ diagnostic trace using the common services
    component in Java SE environments, such as for standalone MQ
    classes for JMS and classes for Java application and Managed
    File Transfer processes, a four digit thread identifier is used.
    
    In some environments (in particular, IBM MQ Managed File
    Transfer) this is not a sufficiently large enough number to be
    able to distinguish between different threads in the trace
    output.
    
    This results in multiple, concurrently running threads sharing
    the same thread identifier when writing to trace files.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This issue affects administrators who are collecting diagnostic
    trace for IBM Support from MQ components written in Java.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    For long running systems where a large number of threads are
    created, used and then destroyed, a four digit thread identifier
    in a trace file does not provide a sufficiently large enough
    number to uniquely identify each thread.  In IBM MQ Managed File
    Transfer agents, for example, IBM Support has observed the
    thread count reach into the hundreds of thousands over the
    lifetime of the JVM.  In such a case, five new threads might be
    allocated the identifiers:
    
    - 248100
    - 248101
    - 248102
    - 248103
    - 248104
    
    within the trace output.  However, with only four digits
    permitted by the current tracing mechanism, the identifiers
    would be truncated from the right.  This would mean all of these
    five threads writing trace points would use the thread
    identifier "2481".
    
    This makes analysis of such trace files significantly more
    difficult when the threads are running concurrently.
    

Problem conclusion

  • The IBM MQ Java common services component, that is responsible
    for the output format of diagnostic trace files, has been
    updated such that:
    
    - eight digit thread identifiers are used
    
    In addition, if the thread identifier uses a number with more
    than eight digits, truncation occurs from the left hand side of
    the number.  For example, a thread with the identifier
    "123456789" will write to trace using the thread id "23456789".
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.0 LTS   9.0.0.8
    v9.1 CD    9.1.4
    v9.1 LTS   9.1.0.4
    
    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

    IT30275

  • Reported component name

    IBM MQ BASE M/P

  • Reported component ID

    5724H7261

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-09-12

  • Closed date

    2019-09-19

  • Last modified date

    2019-09-19

  • 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

    IBM MQ BASE M/P

  • Fixed component ID

    5724H7261

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
19 September 2019