Customizing DDF Reports

Strobe for DB2 DDF provides you with different options for collecting and suppressing data that enable you to focus the content of your DDF Performance Profiles. The options include:

  • Suppressing non-DDF reports
  • Minimum thresholds for total in_DB2 SQL CPU time and total execution time for SQL target statements
  • Minimum thresholds for average in_DB2 SQL CPU time and average execution times for SQL executing statements
  • Different types of requesters, which are the sources of remote SQL
  • Filters that can focus on specific requesters
  • Filtering for a particular DBRM.

The DDF options you specify are listed on the Measurement Session Data report under either the Measurement or Report Parameters section.

Strobe for DB2 DDF reports can be very large, so using these options to focus the content of the DDF Performance Profile can be very helpful, especially if you are using iStrobe for your analysis. (For more information about using iStrobe to analyze DDF reports see Using-DDF-Reports).

Suppressing Non-DDF Reports

By default when you measure a DDF address space, all Strobe reports that are part of the DDF Performance Profile, except for the Measurement Session Data and the DDF reports are suppressed.

If you do not want to suppress the reports, you will get the following non-DDF reports, where 100% of the wait time is attributed to system services:

  • Data Set Characteristics
  • Data Set Characteristics Supplement
  • Program Usage Summary
  • Program Usage by Procedure
  • Resource Demand Distribution
  • Time Distribution of Activity Level
  • Wait Time by Module.

To change whether or not non-DDF reports are suppressed:

  1. Go to the Strobe - Tailor Reports panel.

  2. Type Y next to DDF REPORT PARAMETERS (See the following figure).

    Strobe -Tailor Reports Panel (Scrollable)

    image2021-2-5_21-18-59.png

    The Strobe - DDF Filters and Thresholds panel is displayed (See the following figure).

    Strobe - DDF Filters and Thresholds - Suppressing Reports

    image2021-2-5_21-21-23.png

  3. Type Y next to the Suppress non-DDF reports field to generate only DDF reports and the Measurement Session Data report. Type N to also produce the non-DDF reports, which are usually part of the Performance Profile. Y is the default value.
  4. Press Enter.

Specifying Thresholds to Limit SQL Activity on DDF Reports

You can specify minimum thresholds (in seconds) that must be met or exceeded before any SQL activity will appear on the DDF reports. Strobe applies the thresholds individually to each statement.

You can specify the following thresholds for target and executing SQL statements:

  • Target statements, which are the user’s SQL statements
    • Total in_DB2 SQL CPU time
    • Total execution time
  • Executing statements, which execute SQL on behalf of target statements
    • Average in_DB2 SQL CPU time
    • Average execution time

SQL activity appears on the DDF reports when any or all of the threshold values are met or exceeded:

  • If any of the executing statements meets or exceeds one of the executing statement thresholds, then its target statement and all the associated executing statements also appear on the DDF reports.
  • If any of the target statements meets or exceeds one of the target statement thresholds, then its associated executing statements also appear on the DDF reports.

No SQL activity appears on the DDF reports when none of the minimum thresholds are met or exceeded.

The DDF threshold parameters that were applied when the Performance Profile was created appear in the Report Parameters section of the Measurement Session Data report.

If your DDF reports are too large, try assigning higher values to the minimum thresholds. However, if the reports have little or no output, check if the thresholds were set too high, and if filters were also used, check if they were too restrictive.

To specify minimum thresholds for SQL statement activity on DDF reports:

  1. Go to the Strobe - Tailor Reports panel.
  2. Type Y next to DDF REPORT PARAMETERS (Strobe -Tailor Reports Panel (Scrollable)) to go to the Strobe - DDF Filters and Thresholds panel (Strobe - DDF Filters and Thresholds - Specifying Thresholds). N is the default value.

  3. Type one or more values in the fields, under the Enter DDF thresholds header.
    Valid values are 0—99.99999 seconds in nn.nnnnn format.
    Note: To direct Strobe to ignore a threshold, type 0 or leave the field blank for those thresholds that do not have default values.

    Strobe

     - DDF Filters and Thresholds - Specifying Thresholds
    image2021-2-5_21-24-42.png

  4. Press Enter.

Examples

  • To focus the DDF reports on those target SQL statements whose total in_DB2 SQL CPU times exceed 0.8 seconds or total execution times exceed 0.1 second: type .8 in the Total CPU time field, .1 in the Total Execution Time field, and leave the other two fields blank.
  • To focus the DDF reports on only those executing SQL statements whose average in_DB2 SQL CPU times exceed 0.1 second: type 0.1 in the Average Execution Time field, and to ignore the total in_DB2 SQL CPU times of the target statements: type 0 in the Total CPU Time field.

Specifying the Source of Remote SQL

You can specify what requester information Strobe collects during measurement to generate the DDF SQL Statement by DBRM by Requester report. The requester is the source of the remote SQL running in the DDF address space.

The type of requester is set when Strobe is installed. The default value for the requester is location, if the value was not changed during installation.

You can temporarily override the requester type when submitting a measurement request using the Strobe - DDF Requester panel (Strobe - DDF Requester Panel).

For each measurement request, you can specify a primary and an optional secondary requester from the following list of requesters. If you do not specify a requester, Strobe uses the requester type set at installation.

  • Requester location
    This is the default value for a requester that is set at installation. It can be either the IP address or LU name in the SNA network of the requester that is executing the SQL in the DDF address space.
  • Correlation ID
  • Authorization ID
  • End User’s USERID
  • End User’s Workstation
  • End User’s Transaction.

After you have collected requester information from the measurement, you can then use filters to focus the DDF reports on specific requesters using the Strobe- DDF Filters and Thresholds panel (Strobe - DDF Filters and Thresholds - Specifying Filters).

You can only filter on a requester type for which you collected measurement information.

To specify one or two requesters for a measurement:

  1. Go to the Strobe - Data Collectors panel (See the following figure).

    Strobe

     - Data Collectors Panel - Accessing Capture Options
    image2021-8-11_12-20-10.png

  2. Type Y in the DB2 Data Collectors field and press Enter to display the Strobe - DB2/DDF Data Collector Capture Option panel (See the following figure).

    Strobe

     - DB2/DDF Data Collector Capture Option Panel
    image2021-2-5_21-28-27.png

  3. Type Y in the DDF Requester field to go to the Strobe - DDF Requester panel (Strobe - DDF Requester Panel). N is the default value.
    If you type Y in the Always use as default field, Strobe automatically uses these requester types the next time you submit a measurement request. You do not need to visit the Strobe - Data Collectors panel again, unless you want to change the requester types.
    An S appears if this field was previously selected. If you leave the S, no changes are made to the DDF requester information. To change the DDF requester information, type Y. Typing N has no effect.
  4. Type P to specify a primary requester, or a P and S to specify primary and secondary requesters, under Requester on the Strobe - DDF Requester panel (Strobe - DDF Requester Panel).
    You must specify at least a primary requester, if you do not use the default values. In addition, you cannot specify a secondary requester without a primary requester. At most, you can have two requesters: one primary and one secondary.
    The first time you visit this panel, the default requester type specified during installation appears on this panel. If the default value was not changed during installation, you will see a P next to Requester Location and no secondary requester.
    Strobe - DDF Requester Panel
    image2021-2-5_21-30-3.png
  5. Press Enter.

Report Filtering of DDF Data

Strobe for DB2 DDF provides you with filters for DBRMs and requesters, which can focus the content of the DDF Performance Profile on specific values collected during measurement.

You can assign a specific value to the following filters:

  • DBRM name
  • DDF requesters:
    • Location
    • Correlation ID
    • Authorization ID
    • End User’s USERID
    • End User’s Workstation
    • End User’s Transaction.

The more filters that you specify, the more you limit the DDF report data. The final report output is determined by the intersection of the data from the filters that you specify. If your DDF reports have no output, it means that Strobe could not find data that met the criteria specified by the filters you used. (In addition, if thresholds were also used, check if the thresholds were set too high.)

To filter DDF data that was collected during measurement for DDF reports, type Y next to the DDF REPORT PARAMETERS (Strobe -Tailor Reports Panel (Scrollable)) to go to the Strobe - DDF Filters and Thresholds panel (Strobe - DDF Filters and Thresholds - Specifying Filters).

You can only filter on a requester type for which you collected measurement information. At most there can be only two requester types. The DDF filters support only exact matches and no wildcards. You can filter only on correlation IDs that consist entirely of printable characters.

  1. To specify the following filters:
    • DBRM name
      Type the name of a DBRM next to the Enter DBRM name filter field.
    • Requester location
      Type the IP address or LU name in the SNA network of the requester up to a maximum length of 16, next to the Requester location field.
    • Correlation ID
      Type the correlation ID up to a maximum length of 12, next to the Correlation ID field.
    • Authorization ID
      Type the authorization ID next to the Authorization ID field.
    • End User’s USERID
      Type the end user’s USERID next to the End User’s USERID field.
    • End User’s Workstation
      Type the End User’s workstation next to the End User’s workstation field.
    • End User’s Transaction
      Type the End User’s transaction next to the End User’s transaction field.
  2. Press Enter.
    Strobe - DDF Filters and Thresholds - Specifying Filters
    image2021-2-5_21-34-11.png

Submitting Measurement Requests for DDF Address Spaces

When you submit a measurement request for a DDF address space, Strobe for DB2 DDF automatically measures the DDF address space using the Strobe for DB2 default option DATA COLLECTOR = Y. If this option is set to N on the measurement request, Strobe does not measure the DDF address space. In addition, the SSA installation parameter must be set to YES (default value) or Strobe will not measure the SQL statements.

For more information about the Strobe for DB2 options, see Managing-Db2-and-DDF-Data-Collection. For detailed instructions about submitting measurement requests, refer to the Using-Strobe-to-measure-online-applications-and-batch-programs and the Strobe/ISPF Online Tutorials.

Measurement Session Data Report

When you measure a DDF address space, the following appear on the Measurement Session Data report:

  • DDF appears in the Subsystem section
  • Parameters for suppressing non-DDF reports, minimum SQL thresholds that were specified, and requester filters with their values appear in the Report Parameters section
  • Parameters for requesters and their values appear in the Measurement Parameters section

 

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