Measuring with Strobe/ISPF

This section describes the following information:

• Adding measurement requests for active jobs
• Adding measurement requests for jobs that are not yet executing
• Customizing measurement requests
• Submitting measurement requests as batch jobs.

Getting started

Strobe/ISPF is arranged so that you can specify the measurement information you want to obtain through a minimum number of panels.

The Strobe Options menu is the first screen that appears when you invoke Strobe. From this menu, the first seven options enable you to:

• Set default values
• Generate measurement requests
• Control the measurement session commands
• Produce StrobePerformance Profiles.

Four of the next six options (Options M, L, T, and C) provide additional information about Strobeand Strobe/ISPF. Option M provides information on messages, Option L accesses the Strobelog, Option T accesses the Tutorial, and Option C provides information on the enhancements to Strobefor the current release. Option P accesses the Strobepackaging utility, which is a tool that enables you to send sample datasets to the Compuware Customer Support department, if necessary. To access the online help facility, select Option T (TUTORIAL) from the StrobeOptions menu or press the Help key from any Strobepanel. The tutorial explains how to use Strobe/ISPF and includes a Getting Started section that provides an exercise for measuring and reporting with Strobe.

The last option (Option X) allows you to end your Strobe/ISPF session. The current Stroberelease number, and PTF level appear in the upper right corner of this panel. This information specifies the current version of the Strobesoftware that is installed.

Additional AutoStrobe Options (AutoStrobe Only)

AutoStrobe users can use additional menu options to:

• Work with monitor requests and measurement candidate lists
• Work with groups of measurement requests
• Work with historical data.

Option A (MONITOR/CANDIDATE) enables you to build measurement candidate lists and monitor candidate performance. For more information see AutoStrobe Batch Candidate Lists and Monitoring and Managing AutoStrobe Batch Candidate Processing and Monitoring. Option G (REQUEST GROUPS) enables you to create, edit, and submit groups of measurement requests. For more information, see Using AutoStrobe Request Groups. Option H (HISTORY) enables you to display and analyze measurement session history records. For more information, see Working with AutoStrobe Measurement History Information.

Strobe Options Menu

Submitting Measurement Requests

You have the following options for submitting measurement requests:

• Use the ADD ACTIVE option (Option 1) to submit a measurement request for a job step that is currently executing.
• Use the ADD QUEUED option (Option 2) to submit a measurement request for a job step that is not yet executing.

When you submit an active request, Strobeimmediately begins measuring the job step. When you submit a queued request, Strobe begins measuring the target job step when the job step becomes active.

Additional AutoStrobe Options (AutoStrobe Only)

AutoStrobe users have three additional options for submitting requests:

• Type Y in the SCHEDULE REQUEST field of either the Strobe- Add Active Request or the Strobe- Add Queued Request panels to create a schedule for a measurement request you want to occur on a regular basis.
• Use the MONITOR/CANDIDATE option (Option A) to build a measurement candidate list and submit a candidate monitoring request. For more information about these tasks, see AutoStrobe Batch Candidate Lists and Monitoring and Managing AutoStrobe Batch Candidate Processing and Monitoring.
• Use the REQUEST GROUPS option (Option G) to create, edit, and submit groups of measurement requests. You can submit the request group for Strobeto process immediately, or schedule the request group for Strobeto process at a later time or several dates and times. For more information on request groups see Using AutoStrobe Request Groups.

Adding Measurement Requests for Active Jobs

Submit an active request to measure online applications, as well as batch programs that are running far longer than you expected. For example, if you notice a decrease in the performance of an application executing in an online region, you can initiate a measurement of the application to help determine the cause of the problem. When you submit the request, Strobeimmediately begins measuring the job step.

To add a measurement request for a job step that is currently executing:

1. Select Option 1 (ADD ACTIVE) from the StrobeOptions menu.

2. Press Enter to display the Strobe- Add Active Request panel.
   Strobe- Add Active Request Panel

   

3. Specify the target system in the System field or clear this field to select from a list of systems. For details, see Specifying the Target System.
4. Specify the target job name in the Jobname field or clear this field to select from a list of active jobs. For details, see Specifying the Target Job.

5. Configure the measurement session by providing information for the following fields:

   • Session Duration—how long you want to measure
   • Target Sample Size—how many performance samples you want Strobe to take
   • TSO UserID to Notify—the TSO user ID for Strobeto notify when the request is complete.

   For more information, see Configuring Measurement Sessions.

6. Specify the sample dataset information in the Sample Dataset Information fields, if necessary. For details, see Specifying Sample Dataset Information.

To specify the system on which the target job is currently executing, do one of the following:

• Type the system name in the System field of the Strobe- Add Active Request panel.
• To view a list of all active systems in the sysplex, clear the field.
  1. Press Enter to display the Strobe- System Selection List panel.
  2. To select a system, type S to the left of the system name.

Strobe- System Selection List Panel - Active Measurement Request

Specifying the Target Job

To specify the target job to be measured, choose one of the following:

• Type the job name in the Jobname field of the Strobe- Add Active Request panel.

• To select from list of all active jobs, clear the Jobname field.

1. 
   

   1. Press Enter to display the Strobe- Active Job Selection List panel.

      Strobe- Active Job Selection List Panel 

      

      If you are using Strobefor z/OS UNIX System Services, you can select process IDs to measure from the Strobe- Active Process Selection List panel. See the Options-guide for more information about selecting process IDs to measure.

   2. To select target jobs, type S to the left of the job name. You can select as many as 32 jobs. If the list is longer than one page, press the Down or Up function keys to view the rest of the list. To refresh the list, press Enter without making a selection.
   3. When you have selected your target jobs, press Enter.
   4. Strobe returns you to the Strobe- Add Active Request panel. The name of the first job you selected appears on the panel.
   5. If the Strobe- Active Job Selection List panel is wider than the screen, press the Left Function or Right Function keys to scroll the additional columns horizontally.
   6. To change the format of the Strobe- Active Job Selection List panel, refer to the section Changing the Format of the Active Job Selection List.

The Strobe- Active Job Selection List panel always contains the following types of information:

Specify the scope and duration of the measurement session in the Measurement Session Information fields. Specifying the amount of time you want Strobeto measure and the number of times your application should be sampled provides Strobewith the two most important parameters that determine whether the data collected during measurement is statistically valid.

Try to estimate the session duration as accurately as possible so that Strobeuses the most efficient sampling rate. If you overestimate the duration, Strobemay not gather enough execution samples. If you underestimate the duration, Strobewill gather too many samples and consequently reduce its sampling rate. Underestimation produces a statistically valid profile, but it wastes resources because Strobediscards the extra samples.

Note that for an active request, by default Strobewill stop sampling when the target sample size is reached. The following table provides some guidelines for each of these fields.

Strobestores measurement data in the sample dataset. Therefore, before you submit either an active or queued request, you must supply information about the sample dataset. For the name of the sample dataset, you can accept the installation default prefix and suffix or provide your own. Strobegenerates the rest of the name. You may need to enter other information if you are not using System Managed Storage (SMS). For example, if you are not using SMS, you can specify the unit name and the dataset disposition.

If you are using SMS, fields for data, storage, and management classes appear instead of unit name, volume, and the dataset disposition. Entering data in these fields is optional since SMS provides Strobewith the location of the sample dataset.

Naming the Sample Dataset

Strobedynamically allocates a sample dataset in the MSAS address space. Refer to Task-4-3-External-Security-Considerations in the Advanced-Configuration-Guide for additional security information. For the name prefix, Strobe uses the value either you or the system installer provided. The rest of the sample dataset name is created by Strobewith the format:

prefix.jobname.SsssDddd.[suffix]

• prefix is a period-delimited string of dataset name qualifiers. Your Strobe system programmer may have specified a default prefix. Because the sample dataset is allocated by the MSAS address space, the prefix must be acceptable to any security package at your installation. This prefix and suffix combined cannot exceed 26 characters.
• jobname is the name of the job in which the target program executes.
• sss is the sequence number of the request measuring a particular job: 001 for the first measurement request, 002 for the second, and so on. When Strobefirst activates a measurement request for a job, it increments by one the highest sequence number from its list of requests for the job name and assigns it to the request. It reserves this number until the request is deleted.
• ddd is the sequence number of the dataset within the measurement request. It also denotes the number of measurement sessions conducted under the request.
• suffix is an optional string of characters that can be set at Strobeinstallation as a system-wide default.

For example, if request 456 measuring MYJOB had two measurement sessions, and request 477 measuring MYJOB had three measurement sessions, then the sample datasets for request 456 would be named:

prefix.MYJOB.S001D001, prefix.MYJOB.S001D002and the sample datasets for request 477 would be named:

prefix.MYJOB.S002D001, prefix.MYJOB.S002D002, prefix.MYJOB.S002D003

Reusing Sample Datasets

If Strobefinds a sample dataset with the same name as the one it is about to create, it reuses the dataset, if the originating request has been deleted. When you delete a measurement request, you can lose the contents of datasets associated with the request.

To preserve the contents of sample datasets for requests that might be deleted, you can:

• Rename the associated sample dataset
• Assign a different dataset name prefix to new requests for the same job.

The following table provides an explanation for each sample dataset information field.

Optionally, you can:

• Request that a Performance Profile be automatically created upon completion of the measurement session. For more information, see Producing Profiles Automatically.
• Specify values that govern how Strobemanages the request and specify additional measurement data beyond the basic information returned in a Performance Profile. These optional fields are described in Additional Measurement Options.

(AutoStrobe only) AutoStrobe users can also:

• Schedule a measurement session to be initiated at a later time (or series of dates and times). For more information, see Using AutoStrobe Scheduling.
• Save the measurement request in a request group. For more information, see Using AutoStrobe Request Groups.

Adding Measurement Requests for Jobs Not Yet Executing

When you submit a queued request, Strobeinitiates a measurement task when the target job becomes active. Because you are requesting a measurement session for a job that has not yet begun executing, you can target specific job steps.

AutoStrobe users can also specify lists of step names, step numbers, or program names to measure, or even measure all steps of the job.

To add a measurement request for a job that is not yet executing, complete the following steps:

1. Select Option 2 (ADD QUEUED) from the Strobe Options menu.

2. Press Enter to display the Strobe- Add Queued Request panel.
   Strobe- Add Queued Request Panel

   

3. Specify the target job name in the JOBNAME field. For details, see Specifying the Target Job Name.

4. Specify the target job step in the PROGRAM or STEP fields or for AutoStrobe users, clear these fields to input a list.

   To Measure:	Specify:
   The target job by its program name	The name (as it appears in the PGM= operand of the EXEC statement) in the PROGRAM field.
   The target job by its step name	Type one of the following in the STEP field: The relative step number. The step name. If the step is part of a procedure, specify the step name and procedure step name. For example, if the step name is STEP7 and the procedure step name is PLIXCLG, specify STEP7.PLIXCLG. If the step is part of a nested procedure, specify the step name of the procedure containing the nested procedure, and the procedure step name of the nested procedure. Strobemeasures the first executable step identified by the procedure step name. For more information on specifying nested procedures as target job steps, see Identifying the Target Job.
   Additional AutoStrobe options:
   Multiple steps of a job	Clear the PROGRAM and STEP fields and press Enter. Complete the Strobe- Add Queued Request - Multiple Steps panel as described in Measuring Multiple Steps in a Job (AutoStrobe Only).
   All of the steps of a job	Specify *ALL in the STEP field or Option 4 on the Strobe- Add Queued Request - Multiple Steps panel.

   If you specify more than one step identifier, make sure that the target job step satisfies all conditions. If Strobeidentifies a job step that meets only some of the conditions, it does not measure the job step. If a specified job step name or program name appears more than once in a given job, Strobe measures the first occurrence. To measure a later execution of the step or program, specify the step number in the STEP field.

5. Specify the target system in the SYSTEM field. Clear this field to select from a list of systems. For more information, see Specifying the Target System for a Queued Measurement Request.

6. Configure the measurement session by providing information in the following fields.

   1. SESSION DURATION—how long you estimate the job will run
   2. TARGET SAMPLE SIZE —the number of performance samples
   3. TSO USER ID TO NOTIFY—the TSO user ID for Strobe to notify when the request is complete.

   For more information, see Configuring Measurement Sessions.

7. Specify the sample dataset information in the SAMPLE DATA SET INFORMATION fields. For details, see Specifying Sample Dataset Information.

Specifying Other Report and Measurement Options

The steps for controlling the length and scope of the measurement session and identifying the sample dataset are the same as those for an active request. You can:

• Request that a Performance Profile be automatically created upon completion of the measurement session. For more information, see Producing Profiles Automatically.
• Specify values that govern how Strobemanages the request and specify additional measurement data beyond the basic information returned in a Performance Profile. These optional fields are described in Additional Measurement Options.

Additional AutoStrobe Measurement Options

AutoStrobe users can also:

• Schedule a measurement session to be initiated at a later time (or series of dates and times). For more information, see Using AutoStrobe Scheduling.
• Save the measurement request in a request group. For more information, see Using AutoStrobe Request Groups.

Specifying the Target Job Name

Specify the name of the target job in the JOBNAME field.

AutoStrobe users can insert an asterisk as a wildcard character (*) after a string of one or more characters in the JOBNAME field to measure the first job that meets the specified search criteria. For example, if your installation uses an automated operations package that appends a suffix to an alphanumeric sequence for a job name, you can measure the job without knowing the suffix. If you specify MYJOB*, Strobemeasures the first job whose name begins with MYJOB followed by any string of characters, including blanks.

Measuring Multiple Steps in a Job (AutoStrobe Only)

If you are an AutoStrobe user, you can measure more than one job step at a time:

1. Clear the PROGRAM and STEP fields of the Strobe- Add Queued Request panel.
2. Press Enter to display the Strobe- Add Queued Request - Multiple Steps panel.

3. In the OPTION field, type the number that corresponds to the type of list you wish to specify (1 for programs, 2 for step names, 3 for step numbers, or 4 for all steps in the job).
   Strobe- Add Queued Request - Multiple Steps (AutoStrobe only)

   

4. Type the program names, step names, or step numbers on the underscored lines. You do not have to enter the numbers or names in any particular sequence. Strobewill automatically sort the entries.
5. Press Enter to return to the Strobe- Add Queued Request panel. The value *LIST appears in the PROGRAM or STEP field, indicating that you have specified multiple job steps to be measured as a part of this request.

Specifying the Target System for a Queued Measurement Request

To view a list of all active systems in the sysplex:

1. Clear the System field on the Strobe- Add Queued Request panel.
2. Press Enter to display the Strobe- System Selection List panel. Strobe lists the active systems in the sysplex near the bottom of this panel.

To specify one or more target systems in the sysplex for a measurement session, do one of the following:

• To specify just one system, type the system name in the System field of the Strobe- Add Queued Request panel and, to the left of the name type S.
• To specify all of the systems in the sysplex, type *ALL in the System field of the Strobe- Add Queued Request panel.
• To specify one or more systems, type S to the left of the system name on the Strobe- System Selection List panel and press Enter. When the target job becomes active on one of the systems that you specified, Strobeinitiates a measurement session on that system. If you select more than one system, Strobereturns the value *LIST to the System field of the Strobe- Add Queued Request panel.

It might be easier to exclude a system rather than select many systems. When you exclude one or more systems, all systems, except for the ones that you excluded, are potential targets for the measurement request.

To exclude a system, on the Strobe - System Selection List panel, type E to the left of the system name.

If a system is not currently active, it will not appear on the Strobe- System Selection List panel. To select or exclude one or more systems that are not currently active as potential targets for the measurement request:

1. Type the system name on one of the underscored lines in the middle of the Strobe- System Selection List panel.
2. Type S or E to the left of the name.

Strobe- System Selection List Panel - Queued Measurement Request

Specifying Other Options for a Queued Request

The steps for controlling the length and scope of the measurement session and identifying the sample dataset are the same as the steps for an active request. For more information, see Configuring Measurement Sessions and Specifying Sample Dataset Information.