PM89499: ABEND0C4 AT DSNLCPCR+336 IF MAXCONQN AND MAXCONQW CONTAIN VALUES OTHER THAN THEIR DEFAULTS. DB2 ABENDS WITH RC00E50705

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DB2DDF DB2INACTIVE
  Defects pm89499 dpm89499
          167585 d167585 167664 d167664 167670 d167670
          167715 d167715 167764 d167764 167828 d167828
  An ABEND0C4 in DSNLCPCR can happen if zparms MAXCONQN and
  MAXCONQW are being used to control DBAT queueing. These zparms
  were introduced with PM43293/UK90325. The default setting for
  both is OFF. The ABEND0C4 and subsequent DB2 crash can only
  happen if non default values are specified.
  00E50705 0336 OFFSET0336 DB2TERM DB2ABTERM
  **************************************************************
  Additional Symptoms and keywords:
  . ABEND0C4 AB0C4 S00C4 0C4
     0C4-00000004 00000004 RC00000004
      DSNLCPCR DSNLCPCR+0336 0336 OFFSET0336
     0C4-00000010 00000010 RC00000010
      DSNLQCRP DSNLQCRP+12EE 12EE OFFSET12EE
  . Short on ECSA ssnmDIST DIST storage SOS may occur only if
    DSN6FAC MAXCONQN and/or MAXCONQW is specified.
    DB2STGLK/K
    . LQHD LWEL ROB storage leak:
      LCBLQREP LWEL ESCA pool - DB2 QUEUE ELEMENT POOL
      LCBLQHDP LQHD ESCA pool - DC QUEUE HEADER POOL
      SP231 SUBPOOL231 SUBPOOL SUB POOL 231 KEY 7 07 KEY7 KEY07
      Symptoms may include:
      . 04E-00E2001F, LOC=DSNSLD1.DSNSVBK+06E2
        ABEND04E AB04E S004E 04E 04E-00E2001F 00E2001F RC00E2001F
          DSNSVBK DSNSVBK+06E2 06E2
      . 878-00000004
        ABEND878 AB878 S00878 878 878-00000004 00000004 RC00000004
      . 04E-00E20022, LOC=DSNSFBK.DSNSFBK+059E
        ABEND04E AB04E S004E 04E 04E-00E20022 00E20022 RC00E20022
        DSNSFBK DSNSFBK+059E 059E
    . SRGS storage leak:
      ACOMSRGSPOL SRGS BLOCKS
      Symptoms may include:
      . 04E-00E2000C, LOC=DSNXESR1.DSNSVSVB+0AC2
        ABEND04E AB04E S004E 04E 04E-00E2000C 00E2000C RC00E2000C
        DSNXESR1.DSNSVSVB+0AC2 DSNXESR1 DSNSVSVB+0AC2 DSNSVSVB
        +0AC2 OFFSET0AC2
    . Communication buffer storage leak:
      LCBLSTKP - DCRM I/O BUFFER POOL- LSTK
       04E-00E2000C, LOC=DSNLISKM.DSNSVSVB+0AC2
         ABEND04E AB04E S004E 04E 04E-00E2000C 00E2000C RC00E2000C
         DSNLISKM.DSNSVSVB+0AC2 DSNLISKM DSNSVSVB+0AC2 DSNSVSVB
         +0AC2 OFFSET0AC2
      LCBLSMVL - CMGR64 BUFFER POOL IN SM
  

Local fix

• Set both MAXCONQN and MAXCONQW to OFF. These zparms can be
  dynamically updated.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Distributed Data Facility (DDF) users.   *
  *                 Specifically those who have enabled the      *
  *                 new capabilities provided by APAR PM43293    *
  *                 by utilizing a subsystem parameters (ZPARM)  *
  *                 module with (DSN6FAC) MAXCONQN and/or        *
  *                 MAXCONQW set to a value other than OFF.      *
  ****************************************************************
  * PROBLEM DESCRIPTION: Possible symptoms may include:          *
  *                      - ABEND 0C4-00000004 DSNLCPCR+336       *
  *                      - ABEND 04E-00E2001F DSNSVBK+06E2       *
  *                      - ABEND 04E-00E2000C                    *
  *                        DSNXESR1.DSNSVSVB+0AC2                *
  *                      - ABEND 0C4-00000010 DSNLQCRP+12EE      *
  *                      - ABEND 04E-00E2000C                    *
  *                        DSNLISKM.DSNSVSVB+0AC2                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  APAR PM43293 provided a new capability to control the amount
  of connection request queuing that can occur at members of
  a data sharing group.  The capability is activated by utilizing
  a subsystem parameters (ZPARMs) module where the values of the
  MAXCONQN and/or MAXCONQW parameters are set to a value other
  than OFF.
  When the connection request queue control capability is
  activated, several possible conditions can occur during the
  process of terminating a client connection:
  - If the client application had requested (hop) access to
    remote location data from the DB2 subsystem, then the (hop)
    connections to the remote locations must also be terminated.
    This leads to abend 0C4-00000004 DSNLCPCR+0336 and a
    subsequent termination of the entire subsystem since the
    abend occurs during "must complete" deallocation processing.
  - During connection termination processing, DB2 fails to
    free the associated LWEL and LQHD (and hence ROB) control
    blocks.
    A storage leak will occur in the following storage pool(s).
    . DB2 QUEUE ELEMENT POOL
    . DC QUEUE HEADER POOL
    . ROB
    The storage leak may accumulate to the point of causing
    abend 04E-00E2001F.
    Example:
      04E-00E2001F DSNLVCIP.DSNSVBK +0744
  - During connection termination processing, DB2 fails to
    free storage related to any modified session information,
    such as special registers.
    A storage leak will occur in the following storage pool(s).
    . SRGS POOL
    The storage leak may accumulate to the point of causing
    abend 04E-00E2000C.
    Example:
      04E-00E2000C DSNXESRL.DSNSVSVB+0AC2
  - A rare timing condition exists where a connection may undergo
    MAXCONQ* termination processing while the connection
    environment is still in the process of being inactivated
    after just being accepted.
    This may lead to abend 0C4-00000010 DSNLQCRP+12EE.
  - During connection termination processing, DB2 may fail to
    free communication buffer relate storage.
    A storage leak will occur in the following storage pool(s).
    . DCRM I/O BUFFER POOL
    The storage leak may accumulate to the point of causing
    abend 04E-00E2000C.
    Example:
      04E-00E2000C DSNLISKM.DSNSVSVB+0AC2
  

Problem conclusion

• Numerous changes have been made to correct the reported
  conditions.
  

Temporary fix

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

Comments

APAR Information

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

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

  UK96235 UK96236

Modules/Macros

• DSNLCBFM DSNLCPCR DSNLIENO DSNLQCRP
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UK96235

     UP13/08/14 P F308 ½

• RB10 PSY UK96236

     UP13/08/14 P F308 ½

Fix is available

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