PK41636: QDSTQDBT (LCOMQDBT) VALUE NOT CORRECT

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DB2DDF DDFL09 DB2INACTIVE defects 96798 pk41636 d96798 dpk41636
  QDSTQDBT (LCOMQDBT) value not correctly managed. This value is
  also reflected in the QUEDBAT value of the DSNL092I message of
  the DISPLAY DDF DETAIL command report. The value may be
  incorrectly incremented, or not incremented, depending on the
  condition.
  If new work arrives on an existing inactive connection, andthe
  MAXDBAT threshold has been reached and there are no available
  disconnected DBATs to service the request, the connection must
  wait for a DBAT to become available but the QDSTQDBT value
  is not incremented to reflect this wait.
  If a new connection is accepted by DB2 when the MAXDBAT
  threshold has been reached but there are disconnected DBATs
  available, the QDSTQDBT value will be incorrectly incremented
  even though the connection did not actually have to wait (since
  disconnected DBATs were already available to service the
  request).
  ***********************************
  Additional Symptoms and keywords:
    QDSTQDBT
    DSNL092I MSGDSNL092I QUEDBAT
    LCOMQDBT
    DSN6FAC CMTSTAT INACTIVE
    DSNTIPR DDF THREADS INACTIVE
    DDF Inactive Thread support
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Distributed Data Facility (DDF) users.   *
  *                 Specifically where DB2 is configured with    *
  *                 DDF THREADS = INACTIVE specified             *
  *                 (DSN6FAC CMTSTAT INACTIVE).                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: QDSTQDBT statistics value, which is     *
  *                      also reported as the QUEDBAT value      *
  *                      in the DSNL092I message of the          *
  *                      "Display DDF Detail" command report,    *
  *                      may be incorrect.                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When the DSN6SYSP MAXDBAT limit has been reached, the QDSTQDBT
  statistical value may be incorrectly managed and may reflect a
  value that is too low or too high.
  . If a new request is received on an existing (type 2) inactive
    connection and the MAXDBAT limit has been reached, and
    there ARE NO "disconnected" (pooled) DBATs available to
    service the connection, then the connection request must be
    queued until a DBAT becomes available. In this case, the
    connection DOES wait due to an inadequate MAXDBAT definition
    but QDSTQDBT is not incremented to reflect this DBAT shortage
    condition.
  . If a new connection is received and the MAXDBAT limit has
    been reached, but there ARE "disconnected" (pooled) DBATs
    available to service the connection, then the connection
    request is not queued (since an existing "disconnected"
    DBAT can be used). In this case, the connection DOES NOT wait
    but QDSTQDBT is incorrectly incremented which invalidly
    reflects a DBAT shortage condition.
  The intent of the QDSTQDBT value is to reflect occurrences
  where an inadequate MAXDBAT configuration value may be
  affecting the performance and throughput of remote connections
  into DB2. The incorrect management of this value may reflect a
  MAXDBAT configurational issue that may, or may not, really
  exist.
  

Problem conclusion

• DB2 has been changed to increment the QDSTQDBT value only
  when MAXDBAT has been reached and there are no "disconnected"
  (pooled) DBATs readily available to service the connection.
  

Temporary fix

Comments

• ž**** PE08/03/05 FIX IN ERROR. SEE APAR PK55392  FOR DESCRIPTION
  

APAR Information

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

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

  UK23589 UK23590 UK23591

Modules/Macros

• DSNDDPSB DSNDEXTN DSNLCRNC DSNLILNR DSNLQCRP
  DSNLQDIS DSNLTEXC
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R710 PSY UK23589

     UP07/04/17 P F704

• R810 PSY UK23590

     UP07/04/17 P F704

• R910 PSY UK23591

     UP07/04/17 P F704

Fix is available

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