Strobe for Db2 automatically starts as soon as Strobe detects Db2 activity and is initially configured to report on all types of Db2 application data.

Certain considerations might require you to change the Strobe for Db2 configuration. Does the application you are measuring have any special characteristics? If it contains a large number of SQL statements, you can specify thresholds that statements must meet for Strobe to display their complete text in the Performance Profile.

This section describes how to produce and tailor Strobe Performance Profiles using Strobe and Strobe for Db2.

Creating the Strobe Performance Profile

This section explains several parameters you may want to set depending on the type of information you need to analyze your Db2 environment. Strobe enables you to customize how the Performance Profile reports Db2 measurement data so you can aggregate and suppress information about your Db2 environment according to your needs and interests. The Using-Strobe-to-measure-online-applications-and-batch-programs explains other details about how to produce the Performance Profile.

If you are using Strobe for CICS to measure the performance of CICS transactions that are accessing Db2, you will want to use specific CICS reports that can give you a more complete understanding of your Db2 environment. Refer to Strobe-for-CICS for information about using the CICS Performance Supplement and the transaction reports it provides.

Activity Aggregation and Expansion

Depending on the type of activity it detects, Strobe can either aggregate or provide more detail by expanding the breadth of the information it displays in the Performance Profile. When you examine the reports detailing Db2 activity, you need to know exactly what is represented by the values shown in the report fields, or you might incorrectly view how your code is running. Use the following guidelines when examining the reports:

DBRMs

Strobe for Db2 always aggregates activity in DBRMs that have the same name and creation timestamp or package version number.

SPUFI Files

Strobe for Db2 aggregates activity using the Db2-provided DBRM.

SQL Text Reporting

Strobe for Db2 automatically records the text of the SQL statements that are active during the measurement session.

Controlling SQL Statement Text Reporting

You can control when Strobe displays the entire text of a SQL statement in the Performance Profile by specifying thresholds with two parameters called CPUTEXT and WAITTEXT. The parameter values determine whether a SQL statement has caused enough CPU usage or wait time to appear in either the CPU Usage by SQL Statement or the Wait by SQL Statement reports.

For example, if the CPUTEXT parameter were set to 25.0, full SQL text will be printed for all SQL statements that consume more than 25 percent of the CPU time for a measurement session. If the full text of a SQL statement does not appear in the Performance Profile report in which you are interested, decrease the value for either CPUTEXT or WAITTEXT and re-create the Profile. The default values are 10% for CPUTEXT and 5% for WAITTEXT.

To set these parameters:

1. Enter Y in the Detail Reports field of the Strobe - Produce A Performance Profile panel.
2. In the OTHER PARAMETERS field on the Strobe - Detail For A Performance Profile panel, specify: SQL=CPUTEXT= nn.n where nn.n equals the percentage of in_DB2 execution CPU time consumed, or SQL=WAITTEXT= nn.n, where nn.n equals the percentage of wait time observed for a SQL statement during a measurement session. (You can specify both CPUTEXT and WAITTEXT.) Any value for a SQL statement greater than the percentage specified will cause Strobe to report all of the available SQL text for the statement.

For statements that do not exceed the thresholds specified by either CPUTEXT or WAITTEXT, Strobe truncates the text to a specified number of characters.

• The MAXLEN=nnnn operand controls the number of characters Strobe prints for SQL statements that fall below the threshold values you specified. You must specify a value between 0 and 9999 (default 300) for nnnn. 

  Warning

  Important

   If you enter a value that is not a multiple of 100,  rounds up to the next hundred.

• To suppress the SQL text for statements that do not exceed the specified thresholds, enter 0.
• To print all available text for all SQL statements, specify 0 for CPUTEXT, 0 for WAITTEXT, and 9999 for MAXLEN.

With the STROE or STROXE procedure, specify the SQL=MAXLEN=nnnn option or SQL=CPUTEXT=nn.n or SQL=WAITTEXT=nn.n options.

Attribution Reporting

To limit or suppress the Attribution of CPU Execution Time and Wait Time reports in the Performance Profile, specify corresponding parameters on the Strobe - Tailor Reports panel, as shown in Strobe - Tailor Reports Panel (Scrollable).

Compressing Attribution Reports with Low Activity

You can compress attribution reports for any system service module in which the total CPU or wait time percentage is less than a specified baseline. By default, Strobe will not report on any service module that has consumed less than 2% of the CPU usage during a measurement session, or waits less than 2% of the time of the session. You can change this value through either using ISPF or the Strobe command language.

To set these parameters:

1. Enter Y in the Tailor Reports field of the Strobe - Produce A Performance Profile panel.
2. On the Strobe - Tailor Reports panel, specify a baseline percentage between 0 and 99.9 in the “Compress below %” portion of the ATTRIBUTION REPORTS field.

When you submit a batch job using the STROE or STROXE procedure, specify ATTR=nn.n.

Suppressing All Attribution Reports

You can suppress all Attribution reports.

To set these parameters:

1. Enter Y in the Tailor Reports field of the Strobe - Produce A Performance Profile panel.
2. On the Strobe - Tailor Reports panel, enter Y in the Suppress all portion of the ATTRIBUTION REPORTS field (See the following figure).

With the STROE or STROXE procedure, specify the NOATTR parameter.

 Strobe - Tailor Reports Panel (Scrollable)

Suppressing Db2-Specific Attribution Reports

You can suppress the Attribution of CPU Execution and Wait Time reports for Db2 service modules only.

To set these parameters:

1. Enter Y in the Tailor Reports of the Strobe - Produce A Performance Profile panel.
2. On the Strobe - Tailor Reports panel, enter Y in the Suppress reports for Db2 field (Strobe - Tailor Reports Panel (Scrollable)).

With the STROE or STROXE procedure, specify the NOATTR=DB2 operand.

Using iStrobe with Strobe for Db2

If you have installed iStrobe, a separate BMC product, you can analyze your SQL statements of interest even further using SQL Analysis reports, Stored Procedure SQL activity reports, trigger SQL activity reports, and SQL Run Time Statistics for all SQL Activity reports.

To generate iStrobe output for your Db2 reports, enter I for an iStrobe file in the OUTPUT FORMAT field of any of the following panels:

• Strobe - Produce a Performance Profile (See the following figure)
• Strobe - Create an Auto Performance Profile
• Strobe - Change an Auto Performance Profile.

 Strobe - Produce A Performance Profile Panel

For more information about creating Performance Profiles for iStrobe, refer to the Using-Strobe-to-measure-online-applications-and-batch-programs. For information about using iStrobe, see the iStrobe documentation