PM91162: VERY HIGH DB2 CL2 CPU TIME IN ACCOUNTING RECORDS AFTER A TRAN WITH UDF DID ROLLBACK.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Very high DB2 CL2 CPU time (incorrectly) reported in accounting
  records after a tran with a UDF did a rollback. The CL1 CPU
  time is low. The ET is also low.
  Possible scenario:
  A tran calls a UDF. The UDF executes an SQL statement, and
  returns. The transaction issues a rollback. Then a
  "New User" call is issued before the UDF could be properly
  closed. This can lead to DB2 clocking the class 2 times under
  the wrong agent.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of DB2 for z/OS.                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: This APAR addresses the following 2     *
  *                      problems:                               *
  *                                                              *
  *                      1. An ABEND0C4 in CSECT DSNWAAPI when   *
  *                      executing an IFI READA request with     *
  *                      IFCARA64 bit set to ON.                 *
  *                                                              *
  *                      2. A very high CLASS 2 time can be      *
  *                      displayed in the IFCID accounting       *
  *                      record when a rollback is issued        *
  *                      against a transaction that performed    *
  *                      a UDF.                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  1. When an IFI READA request is issued with IFCARA64 bit set
  to ON, DB2 will assume that the first 8 bytes contain the
  64 bit address of the IFI return area to be used. However,
  this value is incorrectly copied from into internal DB2 buffer
  causing a subsequent ABEND0C4 in CSECT DSNWAAPI.
  
  2. When a UDF is involved in a rollback, the end of transaction
  time is clocked under a different agent structure. As a result,
  calculation to obtain the total CLASS 2 accounting time will be
  performed using an uninitialized start value.  This will result
  in an incorrect total CLASS 2 accounting value.
  

Problem conclusion

• 1. Corrected the DB2 logic that handles the 64 bit value of
  the IFI return area when IFCARA64 bit is ON.
  
  2. Corrected the DB2 logic that calculates the total CLASS 2
  time for transactions that were involved in UDF and were
  rolled back. DB2 will no longer use uninitialized value for
  this calculation.
  

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:

  UI13611 UI13613 UI13614

Modules/Macros

• DSNDQW02 DSNTLDEA DSNTLSUS DSNWAAPI DSNWVSR1
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UI13611

     UP14/01/10 P F401

• RB10 PSY UI13613

     UP14/01/10 P F401

• R910 PSY UI13614

     UP14/01/10 P F401

Fix is available

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