Distribute Vusers among Vuser groups

This task describes how to distribute Vusers in a performance test among the Vuser groups. You distribute Vusers according to the Vuser distribution method you selected for the workload.

You can distribute the Vusers by number, by percentage (manually), by percentage using the relative distribution method, or by goal.

In this topic:

Distribute Vusers by number

• Basic schedule: In the Performance Test Designer window, in the Groups grid, select a group, and in the Vusers column, enter the number of Vusers to allocate to that group.

• Real-world schedule: You define the number of Vusers when you define the test schedule. For details, see Define a schedule for the performance test.

For both run modes, the total number of the Vusers assigned to all the Vuser Groups is displayed in the Groups pane toolbar.

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Distribute Vusers by percentage

1. In the Performance Test Designer window, in the Groups grid, in the Vusers-100% column for each group, enter the percentage of the total number of Vusers to allocate to the group.

   Note: The total of all the groups' percentages must be exactly 100% for the test to be valid.

2. Allocate a total number of Vusers to run in the test:

• Basic mode: In the Groups pane, enter the number of Vusers in the Total Vusers box.

• Real-world mode: You define the number of Vusers when you define the test schedule. For details, see Define a schedule for the performance test.

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Distribute Vusers by percentage using relative distribution

In the Performance Test Designer window, in the Groups grid, click the Relative Distribution button to define a ratio by which to distribute the Vusers from each group. For user interface details, see Relative Distribution in Performance Test Designer > Groups & Workload.

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Distribute Vusers by goal

In a goal-oriented schedule, you define the goals you want your test to achieve, and Performance Center automatically builds a schedule for you based on these goals.

1. Prerequisites

   Before setting up the test, decide which goal you want the test to reach. For details on types of test goals, see Goal types for goal-oriented schedule.

2. Assign each script a percentage of the total test target

   In the Performance Test Designer window, in the Groups grid, enter the percentage of the total goal you want each script to reach during the test in the % of Target column for each group.

   Note: The total of all the groups' percentages must be exactly 100% for the test to be valid.

3. Define a goal for the test

   1. In the Goal Definition For pane, click the adjacent drop-down arrow, and select a goal type.

   2. Configure the goal settings:

      UI Element	Description
      Reach Goal <value> <goal type>	Enter the desired goal (number of Vusers to run, Hits Per Second, or Transactions Per Second). For the Transactions per Second goal type, you also specify a transaction name.
      # of Vusers	Enter a minimum-maximum range of Vusers for the scheduler to run. Note: Available for Hits/Transactions Per Second only.
      Duration Run For <duration>	The amount of time (in days, hours, minutes, and seconds) to run the test.
      Goal Missed	The action to be taken if the target cannot be reached. Stop test and save results. Continue test without reaching goal.
      Schedule Preview	A graphical representation of the goal and load behavior defined for the test.

4. Configure test options (optional)

   By default, Performance Center runs the test using the think time recorded in the script (this might require running additional Vusers in your test in order to reach your target). If necessary, you can disable this setting for the test from the Test Options dialog box.

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Goal types for goal-oriented schedule

You can select the following types of goals for a goal-oriented schedule:

Goal Type	Description
Vusers	Tests if your application can run a specified number of Vusers simultaneously. Running this type of goal-oriented schedule is similar to manually distributing Vusers by number.
Hits per Second/Transactions per Second	These goals test the strength of your server. When you define one of these goal types, the Controller divides the target defined by the minimum number of Vusers specified, and determines the target number of hits/transactions per second that each Vuser should reach. After running each batch of Vusers, Performance Center evaluates whether the target for the batch was achieved. If the batch target was not reached, Performance Center recalculates the target number of hits, transactions, or pages per Vuser, and readjusts the number of Vusers for the next batch to be able to achieve the defined goal. By default, a new batch of Vusers is released every two minutes. If the goal has not been reached after the Controller has launched the maximum number of Vusers, Performance Center attempts to reach the defined target once more by recalculating the target number of hits or transactions, and running the maximum number of Vusers simultaneously. A Hits/Transactions per Second goal-oriented scenario is assigned a Failed status if: The Controller has twice attempted to reach the goal using the maximum number of Vusers specified, and the goal could not be reached. No hits/transactions per second were registered after the first batch of Vusers was run. The number of hits/transactions per second did not increase after the Controller ran a certain number of Vuser batches. All the Vusers that ran failed. There were no available load generators for the type of Vusers you attempted to run.

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