Documenting the monitoring run

For each trace interval, several general reports or overall summaries are generated for the processing that took place. You can use these reports as part of your IMS Monitor run documentation.

It is important to record, as accurately as possible, the conditions under which the trace was taken. Your documentation can include system status information (obtained by the /DISPLAY command) several times before and after the trace, an expected profile of the CCTL transaction activity, and any desired processing events. The trace interval should represent typical processing loads and not be a biased or inadequate historical record.

Adding to the System Configuration report data

The first general report (titled SYSTEM CONFIGURATION) is found under the page heading BUFFER POOL STATISTICS. It shows the modification level of the IMS and z/OS® systems. You can choose to add a list of IMS APARs applied and include the service levels of the application programs, especially if the latter are not permanent programs or are part of a staged implementation. The system configuration output is illustrated in the following section.

Recording the Monitor trace interval

The heading of most IMS Monitor reports carries the trace start and stop times. It is shown in the format YEAR DAY (Julian) HH:MM:SS. The overall length of the trace interval is given in milliseconds under the title MONITOR OVERHEAD DATA. The following example shows how many trace records were placed on the IMSMON data set. An example of the monitor trace interval recording is shown in the following figure.

***IMS  MONITOR***  BUFFER POOL STATISTICS   TRACE START 1993 130   5:55:15   TRACE STOP  1993 130  5:59:49  PAGE 0001
 
                   S Y S T E M   C O N F I G U R A T I O N
 
 
 
                                                 SYSTEM CONFIGURATION      :
                                                    IMS VERSION            :   4
                                                 RELEASE LEVEL             :
                                                 MODIFICATION NUMBER       :

Completing the Monitor run profile

A compact set of processing ratios will be found at the end of the Run Profile report. The statistics summarize, for the monitor interval, the UOR throughput and the degree of DL/I and I/O activity. An example of the report is shown in the following example.

 IMS MONITOR   **RUN PROFILE**              TRACE START 1993 130   5:55:15     TRACE STOP  1993 130   5:59:49  PAGE 0184
TRACE ELAPSED TIME IN SECONDS.............274.6
TOTAL NUMBER OF MESSAGES DEQUEUED........1403
TOTAL NUMBER OF SCHEDULES.................173
NUMBER OF TRANSACTIONS PER SECOND...........5.1
TOTAL NUMBER OF DL/I CALLS ISSUED.......18632
NUMBER OF DL/I CALLS PER TRANSACTION.......13.2
NUMBER OF OSAM BUFFER POOL I/O'S........11236,    8.0 PER TRANSACTION
NUMBER OF MESSAGE QUEUE POOL I/O'S..........0,    0.0 PER TRANSACTION
NUMBER OF FORMAT BUFFER POOL I/O'S..........0,    0.0 PER TRANSACTION
RATIO OF PROGRAM ELAPSED TO DL/I ELAPSED:
              REGION   1:   1.09
              REGION   2:   1.09
              REGION   3:   1.00
              REGION   4:   1.02
              REGION   5:   1.01
              REGION   6:   1.00
              REGION   7:   1.00
              REGION   8:   1.00
              REGION   9:   1.17
              REGION  10:   1.00
              REGION  11:   1.00
              REGION  49:   1.03
              REGION  50:   1.19
RATIO OF DL/I ELAPSED TO DL/I IWAIT:
              REGION   1: 325.65
              REGION   2:  73.49
              REGION   4: 100.35
              REGION   5:  85.76
              REGION   6:  82.99
              REGION  47:  95.64
              REGION  48:  45.93
              REGION  49:   9.22

The lower half of the Run Profile report shows several ratios:

  • Program elapsed time to DL/I elapsed time for each region
  • DL/I elapsed time to wait time during DL/I processing
  • Program elapsed time to other subsystem call elapsed time
  • DL/I elapsed time to other subsystem call elapsed time

Each region is identified by a sequence number, starting at region 1.

There are some generalized processing ratios that are given at the end of several buffer pool statistics reports. You can include them in the documented profile of the trace interval. These are not specific to one UOR or system resource but can be used as indicators of variation across a series of monitor runs. The ratios are:

  • The total number of OSAM reads + OSAM writes + all waits divided by the total number of transactions.

    From the Message Queue Pool report, this ratio indicates on a per transaction basis the physical I/O activity required to handle the scheduling function.

  • The total number of OSAM reads + OSAM writes + BISAM reads divided by the total number of transactions.

    From the Database Buffer Pool report, this ratio indicates on a per transaction basis the physical I/O activity required to handle the database buffering function.

Verifying IMS Monitor report occurrences

When you examine the output from the IMS Monitor Report Print Program, the presence of a report heading does not necessarily mean that appropriate data will be listed. System definition options and utility control statements also affect the content of the output as follows:

  • The output does not include a Call Summary report unless a control statement specifies DLI.
  • The output does not include a set of Distribution reports unless a control statement specifies DIS or DISTRIBUTION. The column headed DISTRIBUTION NUMBER that occurs on many of the reports contains cross-references to items included in the Distribution reports.
  • The output consists of just a Call Summary report if a control statement specified ONLY DLI.

Because many of the summary reports require system status to calculate the difference between start and end values, and this status is obtained during the /TRACE SET OFF processing, the IMS Monitor execution must end before termination of the IMS control region. If the trace was not stopped properly, the following message is issued: 

NO DATABASE BUFFER POOL TRACES AT END TIME ON MONITOR LOG TAPE
****DATABASE BUFFER POOL REPORT CANCELLED****

Similarly, other summary reports are not produced.

The series of reports titled Buffer Pool Statistics do not include a VSAM Buffer Pool section unless the database in IMS.ACBLIB uses the VSAM access method. If VSAM is not used, the following message is issued: 

NO VSAM BUFFER POOL TRACES ON MONITOR LOG TAPE
****VSAM BUFFER POOL REPORT CANCELLED****

If the source data used to formulate a particular IMS Monitor report, or a section of that report, has not been recorded by the IMS Monitor during the trace interval, the report contains only the headings.