DBCTL monitoring data returned to CICS

Monitoring data at the transaction level is passed back to CICS® by DBCTL whenever a TERM request occurs, either explicitly, or implicitly at the end of task termination. The data is appended to the CICS monitoring facility performance record of the issuing task.

The data returned is as follows:
  • PSB name.
  • Elapsed wait time for pool space. In a PSB schedule, when the pool space is insufficient for PSB/DMB blocks, the schedule request is put on a wait queue. The total wait time for it is in this field.
  • Elapsed wait time for intent conflict. In a PSB schedule, when an intent conflict is detected, the schedule request is put on a wait queue. The total wait time for it is in this field.
  • Elapsed time for the schedule request.
  • Elapsed wait time for database I/O.
  • Elapsed wait time for locking. The total wait time to get the PI locks which are local segment level locks.
  • Total number of database I/O counts.
  • Number of DL/I requests for each of the following:
    • Get unique
    • Get next
    • Get next within parent
    • Get hold unique
    • Get hold next
    • Get hold next within parent
    • Insert requests
    • Delete requests
    • Replace requests
  • Total number of DL/I database requests.
  • Number of test enqueues.
  • Number of times requesting the PI locks on segments.
  • Number of waits on test enqueues.
  • Number of times requesting the PI locks on segments.
  • Number of dequeues.
  • Number of times PI locks are released.
  • Number of update enqueues.
  • Number of times the update locks are not available for a request and requires a wait.
  • Number of update dequeues.
  • Number of times requesting the exclusive lock.
  • Number of waits on exclusive enqueues.
  • Number of times the exclusive locks are released.
  • Number of exclusive dequeues.
  • Number of times the exclusive locks are released.
  • DEDB statistics:
    • Number of DEDB requests
    • Number of DEDB I/Os
    • Number of overflow buffers used
    • Number of waits for DEDB buffer
    • Number of unit of work contentions
  • Date of schedule start.
  • Time of schedule start.
  • Date of schedule end.
  • Time of schedule end.
  • Elapsed UOW CPUTIME for DRA thread (see note).

Note: The elapsed CPUTIME field was introduced by IMS APAR PL83370. The CPUTIME represents the time spent in the DRA Thread TCB from the time the PSB is scheduled, to the time the PSB is terminated. CICS always terminates the PSB at the end of the Unit of work (UOW). The CPUTIME does not include any time spent in the DBCTL region.

Calculating CICS and IMS processor times for IMS Version 12 or later

When CICS is connected to IMS Version 12 or later, and is using the open transaction environment (OTE), the CICS-DBCTL database adapter transformer DFHDBAT, uses CICS-managed L8 open TCBs rather than CICS IMS subtask TCBs. This means that the CICS monitoring facility can measure activity that was previously only reported in the IMS data that was returned whenever a TERM request occurred. For example, CICS can now measure the processor time consumed on the IMS thread. When CICS is using L8 open TCBs, the CPU time reported for these TCBs by the CICS monitoring facility includes the IMS elapsed UOW CPUTIME for the DRA thread.

When CICS is connected to IMS Version 12 or later, do not add the processor time from the CICS records (SMF type 110 records) and the IMS elapsed UOW CPUTIME when calculating the total processor time for a single transaction, because the IMS processor time would then be included twice. The total processor time for a single transaction is recorded in the USRCPUT field in the CICS records (performance class data field 008 from group DFHTASK). This field includes all processor time used by the transaction when it was executing on any TCB managed by the CICS dispatcher. CICS-managed TCBs include the QR, RO, CO, and L8 mode TCBs.
Note: The DRA startup table (DFSPZP) option TIMETHREADCPU=NO can be specified so that the IMS elapsed UOW CPUTIME for the DRA thread is not calculated and hence returns zero to avoid counting the IMS processor time twice.

In the OTE, the CICS L8 task processor time can also include the cost of creating an IMS DRA thread.

Also take the capture ratio for CICS and IMS into account. Capture ratio is the ratio of reported CPU time to total used CPU time. For more information, see z/OS Resource Measurement Facility (RMF) Report Analysis.