- 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.
- The statistics domain. This component is responsible for managing statistics
interfaces, for example, SMF and EXEC API.
- 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.
- 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:
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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 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: