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3. IMPLEMENTATION › 3.2 Strategies for DB2 Accounting › 3.2.2 Avoiding DB2 Duplicate Charging

3.2.2 Avoiding DB2 Duplicate Charging


 
 Duplicate charging for CPU time can occur in DB2 when the
 calling region is TSO, BATCH, or IMS because the CPU time
 will be reported in the calling region as well as in DB2.
 
 Special consideration must be given to charging for
 DB2 CPU time when the calling region is CICS.
 
 -- For DB2 Version 6 (and higher) and CICS CTS Version 2.2
    (and higher), duplicate charging can occur for CICS.
    Beginning with CTS 2.2, CICS regions exploit the IBM open
    transaction environment (OTE) to connect with DB2; the DB2
    CPU time is reported in the CICS transaction record as
    well as in DB2.
 
 -- For DB2 Version 5 (or lower) or CICS CTS 2.1 (or lower),
    there is no issue with duplicate charging for CICS because
    the DB2 CPU time is NOT reported back to CICS calling
    regions.
 
 If you charge for DB2 resource utilization from the ACTJDS
 DB2 Resource Journal File and also charge for TSO, batch,
 CICS, and/or IMS resource utilization from the journal files
 associated with those components, then you must take care to
 avoid duplicate charging for CPU times.
 
 The standard computation codes whose associated data elements
 contain DB2 CPU time follow.
 
    Comp   Data
    Code   Element    Description
    ----   -------    -----------------------------------
    1201   DSUTCBTM   TCB Time
    1203   DSUCPUTM   Accumulated CPU Time
    1206   DSUCPODB   CPU Time Only on a DB2 TCB
 
 WARNING:  Beginning with DB2 Version 6, DB2 no longer
           records SRB CPU time for DB2 transactions. Since
           DB2 Version 6, DSUTCBTM and DSUCPUTM are equal.
           Therefore, you should, never select both
           computation codes 1201 and 1203 for charging.
 
           In addition, for DSU file observations where the
           DB2PTASK data element has a value of ACUMAC, CHILD,
           or ROLLUP, or data element DSUCATYP has a value of
           7,8, or 12, DSUCPUTM and DSUCPUTM contain the save
           value.
 
           When you select both computation codes 1203 and
           1206 for charging, only apply charges for
           computation code 1206 in the following
           circumstance:
 
           o When the DB2PTASK value is not ACUMAC, CHILD, or
             ROLLUP
           o and DSUCATYP has a value other than 7, 8, or 12.
             Otherwise you will incur duplicate charging.
 
 AVOIDING DUPLICATE CPU TIME CHARGES IN AN ENVIRONMENT WITH
 SPECIAL PROCESSORS
 
 There are two types of IBM special processors, zSeries
 Application Assist Processor (zAAP) and z9 Integrated
 Information Processor (zIIP).
 
 For DB2 transactions, the portion of CPU time spent executing
 on special processors (zIIP) is kept separate from the
 portion of CPU time used by the transaction while it is
 executing on a standard processor.  The CA MICS data element
 that contains the special processor CPU time is:
 
  DSUCPUZ1 Accumulated CPU Time Consumed on zIIP
 
 There are no duplicate charging issues for special processor
 CPU times.
 
 The CPU time spent by a transaction that could have executed
 on a special processor, but executed on a standard CP because
 a special processor was not available, is considered special
 processor eligible CPU time.
 
 Special processor eligible CPU time is a subset of TCB CPU
 Time (DSUTCBTM) or CPU Time (DSUCPUTM).  The CA MICS data
 element that contains special processor eligible CPU time is:
 
  DSUELGZP Accumulated CPU Time zIIP-Eligible Work
 
 The potential exists for duplicate charging for special
 processor eligible CPU time if you want to use a different
 rate for eligible CPU time than the rate that is used for
 work that had to run on the standard processors.  It is
 important to understand, that if you charge for both special
 processor eligible CPU time and either the TCB or CPU time,
 you will be charging for the special processor eligible CPU
 time twice.
 
 If you want  to charge the same rate for special processor
 eligible CPU time as the rate for TCB CPU time, we recommend
 that you use the COMP codes for DSUTCBTM or DSUCPUTM.
 
 If you want to charge different rates for special processor
 eligible CPU time and non-special processor eligible CPU time
 or non-special processor eligible TCB time, use the following
 computation codes:
 
 o Special Processor Eligible CPU Time
 
 COMP
 CODE   Element    Label
 ----   --------   ------------------------------
 1261  DSUELGZP   Accumulated CPU Time zIIP-Eligible Work
 
 o CPU Time Excluding Special Processor Eligible CPU Time
 
 COMP
 CODE   Element    Label
 ----   --------   -----------------------------------
 1262   DSUXSPTM   CPU Time Excluding Special CPU Time
 
 The computation of DSUXSPTM is:
 
   DSUXSPTM = DSUCPUTM - DSUELGZP
 
 WARNING:  Beginning with DB2 Version 10.1, supported by
           product change DB26790, the raw data used to
           populate data element DSUELGZP is no longer
           collected by DB2, so data element DSUELGZP is set
           to zero by CA MICS.
 
           Prior to DB2 Version 10.1, data element DSPXSPTM
           contained total CPU time (DSUCPUTM) minus
           specialty processor eligible CPU time (DSUELGZP).
 
           Beginning with DB2 Version 10.1, DSUCPUTM and
           DSUXSPTM will always be equal. To avoid duplicate
           charging, you should not charge for both the 1262
           (DSUXPSTM) and 1203 (DSUCPUTM) computation codes.
 
 HOW TO AVOID DUPLICATE CHARGING
 
 You can avoid duplicate charging for DB2 CPU time by using a
 zero rate when the connection identifier (DB2CONN) is TSO,
 BATCH, CICS (see notes above), or an IMS identifier.
 
 This can be accomplished in Rate Table Algorithm
 Specification by using control variable charging as follows:
 
  1) Assign DB2CONN to a DB2ACTn variable in
     sharedprefix.MICS.PARMS(DB2ACRT).
 
     Assigning DB2CONN to a DB2ACTn variable causes it to be
     available in the DAYS timespan, where charging occurs.
 
  2) Select Rate Table (Option 3;6 on the Installation
     Accounting Primary Options Menu), select the DB2 unit if
     necessary, and select the ACTJDS DB2 Resource Journal
     File.
 
  3) If you have not previously done so, select Option 1 and
     enter the file specifications.
 
  4) Select Algorithm Specification, Option 3, from the File
     Options menu and select each algorithm in turn.
 
  5) Enter DB2ACTn (where n is the number of the account code
     that contains DB2CONN) in the Control Variable column for
     the CPU time computation code.
 
  6) Enter the normal rate in the Rate column.
 
  7) Select the row to display the Variable Value
     Specifications panel.
 
  8) Enter rows with control variable values of TSO, BATCH,
     IMS (and CICS CTS Version 2.2 or higher and if DB2
     Version 6 or higher) identifiers, respectively, and rates
     of 0.
 
  9) END from Rate Table and submit MAGRUN when requested.
 
 10) Repeat steps 1 through 9 for each additional DB2 unit.