PM81671: ABEND0C9 RC00000009 AT DSNLEDDA AND OTHER SYMPTOMS AFTER APAR PM43293 WAS APPLIED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DB2DDF DB2DSHR DB2TCPIP
  Defects pm81671 dpm81671 165822 d165822 165992 d165992
  ABEND=0C9-00000009 AT LOC=DSNLDTML.DSNLEDDA+345A AFTER
  APAR PM43293 APPLIED AND ONLY WHEN ZPARM CONDBAT SET TO 0
  ***************************************************************
  Additional Symptoms and Keywords:
   ABEND0C9 AB0C9 S00C9 0C9
    0C9-00000009 00000009 RC00000009
     DSNLEDDA DSNLEDDA+345A 345A OFFSET345A
   SYSPCDB CONDBAT value of zero 0
   DSNL031I MSGDSNL031I 00D351FF RC00D351FF DSNLZRPA DSNLZRPA0001
   DSNL413I MSGDSNL413I
   DSNV408I MSGDSNV408I RESET YES
   DSNV460I MSGDSNV460I V460
   AGNPRMRM
   SQLCODE -1224 SQLCODE1224 SQL1224N SQL01224N is detected by
    remote client environments, and the SQL statement fails to
    be seamlessly rerouted, after the DB2 server detects a
    DSNL027I 00D3003E or 00D3003F condition. The application must
    explicitly reconnect to the DB2 server where this was not
    necessary prior to the PM43293 change. The condition occurs
    because PM43293 caused an AGNPRMRM to be incorrectly returned
    when the 00D3003E or 00D3003F conditions are detected.
    00D3003E RC00D3003E
    00D3003F RC00D3003F
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Distributed Data Facility (DDF) users.   *
  *                 Specifically where:                          *
  *                 * DB2 is a member of a data sharing group    *
  *                   and is configured with a MAX REMOTE        *
  *                   CONNECTED (DSN6SYSP CONDBAT) value of 0,   *
  *                   and/or                                     *
  *                 * DB2 is utilized as a server, via a         *
  *                   TCP/IP connection, on behalf of a          *
  *                   remote DB2 for z/OS requester.             *
  *                 * DB2 is a member of a data sharing group    *
  *                   and is accessed by remote client           *
  *                   environments which utilize the             *
  *                   KeepDynamic Refresh capability             *
  *                   (introduced by DB2 9 APAR PK69339).        *
  *                 DB2 10 for z/OS users only.                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: After PTF UK90325 (APAR PM43293) is     *
  *                      applied, the following conditions may   *
  *                      be observed:                            *
  *                      * Abend 0C9-00000009 DSNLEDDA+345A.     *
  *                      * A DRDA AGNPRMRM reply is returned     *
  *                        to remote DB2 for z/OS requester      *
  *                        systems.                              *
  *                        DB2 for z/OS requester system         *
  *                        symptoms may include:                 *
  *                        . Message DSNL031I displayed          *
  *                          instead of DSNL511I.                *
  *                        . An application may receive SQLCODE  *
  *                          -30020 instead of SQLCODE -30081.   *
  *                        . Message DSNL413I, which may result  *
  *                          in message DSNV460I (V460) being    *
  *                          issued in the -DISPLAY THREAD(*)    *
  *                          TYPE(INDOUBT) command report.       *
  *                      * Distributed client applications       *
  *                        may receive SQLCODE -1224 errors.     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  As part of the new support introduced by PTF UK90325 (APAR
  PM43293), the following problems may be observed:
  * If DDF has been started when the subsystem is a member of a
    data sharing group, DDF will periodically notify z/OS Work
    Load Manager (WLM) of a change in the subsystem's health
    value as the number of remote client connections approaches
    the value specified for the MAX REMOTE CONNECTED
    (DSN6SYS CONDBAT) subsystem parameter.  DDF can be started
    with a set of subsystem parameters or a different set of
    subsystem parameters can be loaded (online changed) where
    the value of CONDBAT is 0.  When CONDBAT is 0, remote
    clients cannot connect to this DB2 subsystem because the
    DDF server capability is disabled.  However, the new
    (APAR PM43293) DB2 system health notification capability
    did not consider the condition where CONDBAT is 0 which
    results in a divide by 0 exception (abend 0C9-00000009).
  * DB2 for z/OS requesters do not expect a DRDA AGNPRMRM
    (Agent Permanent Error reply message) to be returned from a
    DB2 for z/OS server when the server agent abnormally
    terminates.  Thus, once PTF UK90324 is applied to a DB2
    for z/OS server, a server agent abend condition will be
    reported as a DRDA AGNPRMRM (Agent Permanent Error) reply
    message rather than a connection failure.  When a DB2 for
    z/OS requester sees this condition, it will issue message
    DSNL031I (REASON=00D351FF, ERROR ID=DSNLZRPA0001) instead of
    message DSNL511I, and return SQLCODE -30020 instead of
    SQLCODE -30081 to an application.
    Additionally, if the server agent abend is detected during
    commit processing, the DB2 for z/OS requester may also issue
    message DSNL413I in conjunction with message DSNL031I. This
    will result in the -DISPLAY THREAD INDOUBT command reporting
    a thread requiring manual intervention (RESET=YES and message
    DSNV460I) to resolve.
  * Distributed applications using the IBM Data Server Driver or
    Client product family that have been configured to utilize
    the KeepDynamic Refresh capability (introduced by DB2 9 APAR
    PK69339) do not expect a DRDA AGNPRMRM to be returned from a
    DB2 for z/OS server when the server has determined that the
    thread/connection should be refreshed. As such, the client
    application may now receive a SQLCODE -1224.
  

Problem conclusion

• DB2 has been changed as follows:
  * DB2 will now ensure that the MAX REMOTE CONNECTED (DSN6SYSP
    CONDBAT) subsystem parameter is not 0 before determining
    whether or not WLM must be notified of a change in the
    subsystem's health.  If CONDBAT is 0, no notification of
    the subsystem's health will be made to WLM because no
    remote client work can be accepted by the member.  This
    means that the WLMHEALTH value displayed in message DSNL094I,
    issued as a result of the -DISPLAY DDF DETAIL command, will
    be 0.  The subsystem health value will still be reported by
    message DSNV507I, which is issued for the ACTIVE MONITOR as
    a result of the -DISPLAY THREAD(*) TYPE(SYSTEM) command.
  * DB2 will no longer return an AGNPRMRM to a DB2 for z/OS
    requester.  That is, relative to remote DB2 for z/OS
    requester systems only, DB2 server AGNPRMRM reply behavior
    introduced by APAR PM43293 has been restored to prior
    behavior.
    Users should be aware that if symptoms are observed on DB2
    for z/OS requester systems, the solution is to apply this
    change to the associated DB2 10 for z/OS server system.
  * DB2 will no longer return an AGNPRMRM to a distributed
    client being terminated for KeepDynamic Refresh purposes.
  

Temporary fix

Comments

APAR Information

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

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

  UK93177

Modules/Macros

• DSNLAGNT DSNLAGNX DSNLCTRC DSNLDALB DSNLEDDA
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UK93177

     UP13/04/20 P F304

Fix is available

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