Design overview

CICS® statistics support is divided into the following components:

  1. The operator interface. This component is responsible for interfacing to the various CICS-supported terminals, analyzing the input string and then invoking the statistics domain to perform the appropriate management operation. This function is provided by the CEMT transaction, and also by the EXEC API.
  2. The statistics domain. This component is responsible for managing statistics interfaces, for example, SMF and EXEC API.
  3. The statistics update logic. This code is inline in the relevant resource manager. In this way the control function of statistics is centralized, but the management and updating of the statistics fields is given to the resource owner.
  4. The statistics data collection and reset. For all collection types except unsolicited (see below), the collection mechanism is the same. The owning domain is invoked by statistics domain to supply a record that contains the domain’s statistics. When this record has been formed, the domain then calls statistics domain to place the data on the SMF data set.

    There are five types of collections:

    1. Interval. The collection interval default is 3 hours. This may be changed by the user. The minimum value is 1 minute, the maximum 24 hours. On an interval collection, each called domain collects and resets its statistics counters. No action is taken if the statistics recording status is OFF.
    2. Requested. Statistics may be requested using the PERFORM STATISTICS function provided by the CEMT transaction or the EXEC API. The data recorded is for the period between the last time statistics were reset and the time the request was made. Statistics are reset on an interval, end-of-day, or requested-reset collection; they can also be reset, without a collection, when changing the statistics recording status from ON to OFF, or from OFF to ON.

      This type of collection can obtain statistics from some or all domains, as requested. Each called domain collects, but does not reset, its statistics counters.

      Requested statistics are collected even if the statistics recording status is OFF.

    3. Requested-reset. This collection is similar to requested statistics, except that it always obtains statistics for all domains, and each called domain resets its statistics counters after collection.

      Requested-reset statistics are collected even if the statistics recording status is OFF.

    4. End-of-day. This collection occurs when the system is quiescing. A logical end-of-day time may be specified. The default time is midnight. This is primarily for continually running systems. The collection is then made at this time, and the called domain collects and resets its statistics counters.

      End-of-day statistics are collected even if the statistics recording status is OFF.

      Daily systems that are taken down after midnight should change the logical end of day to a time when the system is not operational.

      If the user wishes to simulate shutdown statistics, the interval can be set to 24 hours. An end-of-day report, which contains total figures for the CICS run up to the end of the day, can then be printed by DFHSTUP.

    5. Unsolicited. For dynamically allocated and deallocated resources, the resource records its statistics just before it is deleted; for example, an autoinstall terminal that logs off and is thereby deleted. USS statistics are written to SMF regardless of the statistics recording status (STATRCD).

    By default DFHSTUP formats the statistics for all types of collection, for all the specified APPLIDs. However, if you specify the EXTRACT control parameter but not COLLECTION TYPE, only the extract exit is invoked and no other statistics output is produced.

  5. The statistics formatting control. The offline utility DFHSTUP opens the statistics data set, which is an unloaded SMF data set, and the I/O interfaces to that data set. This routine then browses the data set and formats the statistics.

    Reports may be produced for any or all of the five types of statistics collections.

    DFHSTUP also provides the option of producing a summary report for selected CICS applids. The summary report is constructed from all the statistics contained in the interval, requested-reset, end-of-day, and unsolicited collections. Requested statistics are not involved in the production of the summary report.

  6. The extract statistics reporting function. This is a DFHSTUP exit that takes statistics data from the input SMF data set and passes it to a user program for processing in order to create tailored statistics reports. DFH0STXR is a sample program designed to exploit the extract reporting function. There are also two skeleton exits; an assembler extract exit called DFH£STXA, and a COBOL extract exit called DFH0STXC. These show the format and structure of the interface between DFHSTUP and the extract exit.

    Specifying the extract statistics reporting function changes the default DFHSTUP report settings. If you specify only the EXTRACT control statement, only the extract exit is driven; other DFHSTUP reports are suppressed. If EXTRACT is specified, other statistics report control statements, such as SUMMARY, must also be specified to ensure that the appropriate reports are produced.

DFHSTUP operation

DFHSTUP runs as a separate MVS™ job and extracts all or selected entries from the unloaded SMF data set. The types of entries to be processed by this program are specified in the SYSIN data set. Entries that can be selected for processing include:

You can also select:

Further information about using DFHSTUP is given in the CICS Operations and Utilities Guide.

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