IBM Support

IT07049: PCOM: TN3270 SESSION HANGS WHEN RUNNING TSO APPLICATION THAT SENDS LARGE AMOUNT OF CHAINED DATA

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APAR status

  • Closed as program error.

Error description

  • Customer migrated from PCOM 5.9.2 to PCOM 6.0.10 (20140409) and
    is having a session hang in some workstations.
    .
    In the PCOM trace we see that the hang condition occurs while
    transferring large amount of data using CONTROL-M (in this
    case) under NVAS/TSO.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users of IBM Personal communications connected to z      *
    * series host.                                                 *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * With large chained data from Z series host, sometimes the    *
    * users may face the following symptoms:                       *
    * 1. IBM Personal communications display sessions may hang;    *
    * 2. The emulator sessions may notice slow down in             *
    * performance.                                                 *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The session hang is observed when there is large volume of data
    from the host where the definite response (TN3270 RESPONSE-FLAG)
    is not requested. The problem was caused by an incorrect pointer
    arithmatic that took place only when TN3270 header was split
    across TN3270 data packets.
    
    The performance slow down was due to a delay in processing the
    incoming data packets. This can be seen only when definite
    response is not sought.
    

Problem conclusion

  • To address the session hang problem, the pointer arithmatic code
    has been corrected. Considering the sensitivity of the code, a
    pcswin.ini keyword has been introduced to enable the fix. To
    enable the fix, please add the following keyword to pcswin.ini
    file:
    
    [Telnet]
    HandleSplitDS=Y
    
    Additional code changes have been put in place to improve
    performance. The fix is independent of the above keyword.
    
    Fix scheduled for IBM Personal Communications 6.0.14 Refresh
    Pack.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT07049

  • Reported component name

    PCOMM V5 COMBO-

  • Reported component ID

    5639I7000

  • Reported release

    60A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-02-09

  • Closed date

    2015-03-20

  • Last modified date

    2015-03-20

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

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

Modules/Macros

  • pcstlnet
    

Fix information

  • Fixed component name

    PCOMM V5 COMBO-

  • Fixed component ID

    5639I7000

Applicable component levels

  • R60D PSN

       UP

[{"Line of Business":{"code":"LOB35","label":"Mainframe SW"},"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSEQ5Y","label":"Personal Communications"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"60A"}]

Document Information

Modified date:
26 September 2021