IBM Support

OA35194: DLRPL SP227 CSA GROWTH IPRESOLV HOSTNAME RESOLUTION

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Below the line CSA growth can occur in SP227 KEY6 due to
    stranded DLRPL control blocks when Enterprise Extender
    IPRESOLV is non-zero and HOSTNAME RESOLUTION timeouts occur.
    Stranded VTALLOC storage is x'265' bytes long.
    SYSLOG may include the following messages:
    IST1893I NAME-TO-ADDRESS RESOLUTION FAILED
    IST1909I REMOTE HOSTNAME remotehostname
    

Local fix

  • Circumvention is to code IPRESOLV=0 on both XCA major node
    (PORT) and all Enterprise Extender switched major nodes.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All using predefined switched PU Enterprise  *
    *                 Extender (EE) connections with HOSTNAME      *
    *                 defined on the PATH, and using a non-zero    *
    *                 value for IPRESOLV, which is also            *
    *                 defined on the PATH.                         *
    ****************************************************************
    * PROBLEM DESCRIPTION: Subpool 227 CSA (Key 6) storage below   *
    *                      the line usage increases.  This         *
    *                      increase is due to DLRPL control blocks *
    *                      not being freed during dial-out         *
    *                      processing.                             *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The problem is summarized as follows:
    1) A dial-out request is initiated to establish an EE
       connection for a switched PU.
    2) The switched PU PATH definition, within the switched
       major node, contains a HOSTNAME of that
       of the partner EE node.  This particular
       PATH also has a non-zero value specified for IPRESOLV.
       IPRESOLV is a parameter used to timeout the hostname
       resolution request initiated to the TCP/IP stack.
    3) Module ISTACCQH receives control to initiate CONNOUT
       processing.  Since HOSTNAME is coded on the PATH definition,
       the GAIPATH routine gets control to handle HOSTNAME
       resolution processing.  A DLRPL control block is allocated
       for this process.  A timer is set to limit the length of
       time the process will wait on HOSTNAME resolution.  The
       timer is set to the value specified for the IPRESOLV
       definition.
    4) ISTINCDP is dispatched to process the hostname resolution.
       A subtask is kicked off to invoke module ISTAUCEX to service
       this request.
    5) In this case, the TCP/IP stack does not return the hostname
       resolution request prior to the IPRESOLV timer expiring.
    6) Module ISTACCQH is driven with the IPRESOLV TQE.  This
       causes subroutine TQEPPROC to allocate a PURGE DLRPL
       to purge the outstanding hostname resolution request DLRPL.
       The PURGE DLRPL is sent to ISTINCDP for processing.
    7) ISTINCDP is dispatched to process the PURGE DLRPL, but
       the hostname resolution DLRPL is not found by ISTINCDP.
       This leaves the original DLRPL, allocated in step 2,
       stranded.  Over time, this process can be cause a storage
       creep in SP277 below the line storage.
    

Problem conclusion

  • ISTINCDP - Modified the definition of QELEMENT within subroutine
               QMANAGER to match that of the corresponding
               DLRVT_SSTBLK structure.  The definition mismatch
               caused ISTINCDP not to locate the hostname resolution
               DLRPL, which is mapped by the QELWKE within the
               QELEMENT structure.
    ISTAUCLA - Included for maintenance purposes.
    

Temporary fix

  • *********
    * HIPER *
    *********
    

Comments

APAR Information

  • APAR number

    OA35194

  • Reported component name

    VTAM V4 MVS/ESA

  • Reported component ID

    569511701

  • Reported release

    1B0

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2010-12-15

  • Closed date

    2011-01-11

  • Last modified date

    2011-04-04

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

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

    UA58708 UA58709

Modules/Macros

  • ISTAUCLA ISTINCDP
    

Fix information

  • Fixed component name

    VTAM V4 MVS/ESA

  • Fixed component ID

    569511701

Applicable component levels

  • R1B0 PSY UA58708

       UP11/03/03 P F103 Ž

  • R1C0 PSY UA58709

       UP11/03/03 P F103 Ž

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"1B0","Edition":"","Line of Business":{"code":"","label":""}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSCY4DZ","label":"DO NOT USE"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"1B0","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
04 April 2011