Statistics Collection

A DC/UCF system collects and writes five types of statistics:

System
Task
Transaction
CA ADS dialog
DC/UCF histograms

System Statistics

System statistics record data on a system-wide basis. System statistics are always collected. They are written to the system log:

At normal system shutdown.
At an interval specified by the STATISTICS parameter of the system generation SYSTEM statement.
Upon explicit request with a DCMT WRITE STATISTICS command.

Task Statistics

Task statistics record data on a by-task basis. Task statistics are collected only if requested by means of the STATISTICS TASK WRITE parameter of the system generation SYSTEM statement. You can specify whether separate task CPU-time statistics are to be maintained for system-mode time and user-mode time. Statistics for a task are written to the system log when the task terminates.

Note: Collecting and writing tasks statistics generates a large amount of data and increases overhead.

Transaction Statistics

Transaction statistics record data on a logical unit of work which can span multiple tasks. Transaction statistics are collected only if task statistics collection is enabled.

The collection of transaction statistics is enabled either during system generation by means of the STATISTICS TASK TRANSACTION parameter of the SYSTEM statement or at runtime by means of the TRANSACTION parameter of the DCMT VARY STATISTICS command.

At runtime, the system collects transaction statistics only when requested to do so by a user program.

CA ADS Dialog Statistics

CA ADS dialog statistics record data on a by-dialog basis. Statistics can be collected for all dialogs or for selected dialogs. Dialog statistics can be collected only if transaction statistics collection is enabled.

The collection of dialog statistics is enabled either during system generation by means of the DIALOG STATISTICS parameter of the ADSO statement or at runtime by means of the DCMT VARY ADSO STATISTICS command. Individual dialogs are selected for statistics collection either during system generation by means of the ADSO DIALOG STATISTICS parameter of the PROGRAM statement or at runtime by means of the ADSO STATISTICS parameter of the DCMT VARY PROGRAM statement.

DC/UCF Systems Maintain Histograms

The DC/UCF system maintains additional statistics in the form of histograms. Histograms show statistical data for events in terms of frequency of occurrence within predefined value ranges. For example, one histogram may show the number of loads into the program pool of programs of up to 250 bytes, of 251- to 500-byte programs, of 501- to 750-byte programs, and so forth.

Types of Histograms Maintained by DC/UCF Systems

The system maintains the following histograms:

System-wide histograms are always maintained.
By-task histograms are maintained only if requested by means of the STATISTICS TASK COLLECT parameter of the system generation SYSTEM statement.
By-line histograms are maintained only if requested by means of the STATISTICS LINE parameter of the system generation SYSTEM statement.

All histograms maintained by the system are written to the log whenever system statistics are written to the log.

You can run reports to retrieve statistics from the system log.

More Information:

For more information about the SYSTEM statement, see System Statement.
For more information about DCMT commands, see the CA IDMS System Tasks and Operator Commands Guide.
For more information about the ADSO and PROGRAM statements, see ADSO Statement and PROGRAM Statement.
For more information about the DCMT commands, see the CA IDMS System Tasks and Operator Commands Guide.
For more information about running statistics reports, see the CA IDMS Reports Guide.
For more information about the statistics collected by the DC/UCF system, see the CA IDMS System Operations Guide.