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PK48255: CICS REGION HANGS AND/OR AEXY ABENDS OCCUR WHEN LOADING PROGRAMS AT THE SAME TIME AS MANIPULATING DYNAMIC LIBRARY RESOURCES.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • You are using dynamic LIBRARY resources to load new instances of
    programs.  At the same time, you are manipulating dynamic
    LIBRARY resources, in particular browsing LIBRARY resources and
    setting attributes of LIBRARY resources.  You find that the CICS
    region hangs, or that you are seeing AEXY (task purged) abends,
    or both.   The situation is sometimes alleviated by increasing
    the values of MAXTASKS and EDSALIM.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS Users                               *
    ****************************************************************
    * PROBLEM DESCRIPTION: Attempts to browse or set attributes of *
    *                      dynamic LIBRARY resources at the same   *
    *                      time as program loading activity result *
    *                      in AEXY abends or a CICS region hang.   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Module DFHLDLB3 handles manipulation of dynamic LIBRARY
    resources, including browsing through the LIBRARY resources
    installed in the system, or setting the attributes of
    multiple LIBRARY resources.  This manipulation must be
    serialized with the processing that locates programs
    prior to loading.
    
    In situations where there is a large amount of LIBRARY
    manipulation in progress, waits resulting from this
    serialization can cause transactions to be purged with
    abend AEXY, or can even cause the CICS region to hang.
    
    This situation is more likely to occur at low values of
    MAXTASKS or the EDSALIM system initialization parameter.
    
    Additional Keywords. ABENDAEXY
    

Problem conclusion

  • The serialization mechanism has been changed so that
    the browse processing used when manipulating dynamic
    LIBRARY resources does not conflict with the locking used
    for locating programs for loading.
    
    This change involves adding a new type of Loader Domain
    Browse Element (LDBE) for LIBRARY browses, and a new
    field to the Loader Global Area as an anchor for the
    chain of LIBRARY LDBEs.  This increases the length of
    the Loader Global Area to X'0400'.
    
    The CICS Transaction Server for z/OS version 3 release 2
    CICS Supplementary Data Areas, GC34-6864-00, will be updated
    in the topic on LDCBS Loader Domain Control Blocks
    as follows:
    ---------------------------------------------------------------
     The LDBE LIBRARY chain anchor is added at the end of the area,
     to avoid changing any offsets. The existing reserved fields
     are preserved for service updates.
    ---------------------------------------------------------------
     (3E4)   FULLWORD        4    LDBE_LIB_
                                  CHAIN_SIZE
                                             Size of LDBE chain for
                                             LIBRARYs
     (3E8)   CHARACTER      24    LDBE_LIB_ANCHOR
                                             Anchor for LDBE chain
                                             for LIBRARYs
     (400)   CHARACTER       0    *
    
    (b) The LDBE Loader Domain Browse Element will be changed
    at offset (18) as follows, where LDBE_LAST_CPE_ADDRESS is
    an existing field, which is overlaid with this change by
    LDBE_LAST_PLIBE_ADDRESS
    
    (18)   CHARACTER       4    *
    (18)   ADDRESS         4     LDBE_LAST_
                                 CPE_ADDRESS
                                             Addr last CPE browsed
    (18)   ADDRESS         4     LDBE_LAST_
                                 PLIBE_ADDRESS
                                             Addr last PLIBE browsed
    
    (c) The LDBE Loader Domain Browse Element will also be changed
    at offset (24) as follows, where LDBE_LAST_LIBRARY_NAME
    replaces LDBE_PLIBE_CTRL.
    
    (24)   CHARACTER       8     LDBE_LAST_
                                 LIBRARY_NAME
                                              LIB name from PLIBE
    
    (d) New constants will be added to the LDBE associated constants
    as follows
      8  CHARACTER   LDBE_LIB   LDBE_LIB_ID_STRING
      8  CHARACTER   LDBE_LAN   LDBE_LIB_ANCHOR_ID
    

Temporary fix

  • FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PK48255

  • Reported component name

    CICSTS V3 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    500

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-07-03

  • Closed date

    2007-08-14

  • Last modified date

    2007-09-04

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

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

    UK28122

Modules/Macros

  •    DESPGDUF DFHKEDUF DFHLDCBD DFHLDCBS DFHLDDM
    DFHLDDMI DFHLDDUF DFHLDLB  DFHLDLB2 DFHLDLB3 DFHLDLD  DFHLDLD1
    DFHLDLD2 DFHLDLD3 DFHLDNT  DFHLDST  DFHLDSVC DFHLDTRI DFHPGDUF
    

Publications Referenced
GC34686400    

Fix information

  • Fixed component name

    CICSTS V3 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R500 PSN UK28122

       UP07/08/16 P F708

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.

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Document Information

Modified date:
04 September 2007