Distribute load generators

This topic describes the different types of load generators, and how to distribute them to groups in a performance test. It also describes how to assign elastic load generators to a test.

In this topic:

About load generators

A load generator is a host machine on which Vusers run during a test. There can be many load generators for a given test. While these Vusers run, they create load on your system, enabling you to analyze your system under load.

A load generator can be located on either a local computer or in the cloud. A performance test can include both local and cloud-based load generators.

Below are the different types of load generators:

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Customize load generator attributes

You can customize load generator attributes.

When customizing load generator attributes, consider the following:

• Create attributes that represent properties about your hosts that differentiate one host from another host when using them for performance testing.

• Because you can select multiple attributes for your host, you can define an unlimited number of host attributes. They do not need to be related.

• Host attributes can refer to anything. For example, Host Memory - High, Spanish environment, Very slow machine.

Customize host attributes

1. In LoadRunner Enterprise Administration, select Maintenance > Hosts, and click Manage Host Attributes.

2. To add an attribute, click Add Host Attribute . Enter a name for the attribute in the Add New Host Attribute box, and click Add. The host attribute is added to the host attributes list.

3. To delete attributes, select the attributes you want to delete and click Remove Host Attribute . The selected host attributes are removed from the host attributes list.

4. To edit an attribute, select the attribute you want to change and click Edit Attribute . Modify the attribute as required, and click Close.

Assign attributes to hosts

1. In LoadRunner Enterprise Administration, select Maintenance > Hosts, and select the hosts to which you want assign attributes.

2. In the Hosts toolbar, click Assign Host Attributes.

3. Select the attributes to assign to the hosts, and click Assign.

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Distribute load generators among Vuser groups

This task describes how to distribute load generators among Vuser groups participating in the performance test.

1. Prerequisites

   Add Vuser groups to participate in the test. For details, see Define test workloads.

2. Distribute load generators

   1. In the Performance Test Designer window, select the Groups and Workload tab.

      If load generators have already been assigned to a group, the script name and type, and the number of assigned Vusers and load generators are displayed. Click Show LG names to display the names of the load generators. You can also view details of assigned load generators in the Load Generators tab.

      Click Filter to filter the list of groups displayed in the grid. For details, see Filter.

      If you want to replace the script assigned to the group with a different script, select the script and click Replace script for existing group . Select a script to replace the existing one assigned to the group, and click Replace & Close.

   2. From the Groups pane toolbar, click Assign LGs . The Assign Groups to Load Generators dialog box opens.

      Use the Groups pane to select Vuser groups to which you can assign or remove load generators.

      • Click to filter the load generators being displayed by name. To select all the Vuser groups, select the checkbox next to the column heading.

      • Indicates the total number of Vusers assigned to the Vuser group.

      • Indicates the number of load generators assigned to the Vuser group.

      Use the Load Generators Pane to select the type of load generators you want to assign to each group (you can assign one or more load generators to multiple Vuser groups at once):

      LG Type	Description
      Specific	Enables you to select load generators from the project's host pool to assign to the Vuser groups in the test, or to remove them from the Vuser groups. . Enables you to filter the information being displayed in grid. Name. The name of the load generator. Note: While hosts from older installations of LoadRunner Enterprise (up to three versions earlier) are still supported and are colored orange, we recommend upgrading them to the current LoadRunner Enterprise version before using them. Versions displayed in red are no longer supported and cannot be used to run tests. Status. The status of the load generator: Operational, Non-operational. Assigned load generators must be operational during runtime. State. The current state of the load generator. This includes Idle, Installing, Rebooting, Running. Location. The location of the load generator. Purpose. The purpose of the load generator: Controller, Load Generator, Data Processor, or a combination of these. Note: Only the hosts in the pool with at least a Load Generator purpose are displayed. No. of related groups. The number of Vuser groups to which the load generator is assigned. If a load generator has been assigned to groups, you can click to display the related groups list or to unassign groups.
      Automatch	Enables you to select automatch load generators to assign to Vuser groups in the test, to remove assigned automatch load generators from the Vuser groups, and to add more automatch load generators for the test. Add LGs. Click to add more automatch load generators for the test. Enter the number of load generators in the adjacent box, and click Add. Name. The name of the automatch load generator. By default, these are named LG1, LG2, and LG<n+1> equivalent to the number of automatch load generators that you want to provision. To select all load generators in the list, select the checkbox next to the column heading. Properties. The properties by which the automatch load generator is matched up with a specific load generator in the host pool of the project at runtime. You can specify properties for an automatch load generator in the Load Generator Management dialog box (in the Performance Test Designer window, select Groups and Workload, and click More >  LG Management in the Groups pane toolbar). For details, see Manage load generator types. No. of related groups. The number of Vuser groups to which the load generator is assigned. If a load generator has been assigned to groups, you can click to display the related groups list or to unassign groups.
      Elastic Cloud	Enables you to assign or unassign elastic cloud-based load generators to or from Vuser groups, and to add additional cloud load generators to the test. For details, see Provision elastic cloud load generators. . Opens the Add New Elastic Cloud dialog box, enabling you to add more cloud load generators for the test. Select the load generators and the number of each that you want to add. You can filter the list of load generators displayed in the grid by account, location, size, and/or operating system. Click Add to add the selected load generators and close the dialog box, or Add & Another to add and keep the dialog box open enabling you to add additional cloud load generators. . Click to unassign the selected cloud load generators. Name. The name of the cloud load generator. By default, these are named CLOUD1, CLOUD2, and CLOUD<n+1> equivalent to the number of cloud load generators that you want to provision. Template Name. Name of the cloud load generator template. OS. Operating system of the cloud load generator. Location. Geographic location (region) of the cloud load generator. Account. Name of the cloud provider (Amazon Web Services or Microsoft Azure). Size. The hardware configuration of the machine from which the load generator is provisioned. This impacts the storage and memory.
      Elastic Docker	Enables you to assign or unassign elastic Dockerized load generators to or from Vuser groups, and to add additional Dockerized load generators to the test. For more on elastic Dockerized load generators, see Automatic provisioning of Docker hosts. Add LGs. Click to add more Dockerized load generators for the test. Enter the number of load generators in the adjacent box, and click Add. Image Name Selector. Select which load generator image to use for the test. The images assigned to the project are determined by the administrator (in Deploy and manage Docker host images). Memory/CPU Limit Selector. Specify how much of the available memory (in gigabytes) and CPU resources a container can use during a performance test run. Note: If resource limits are set by your LoadRunner Enterprise administrator (in Set up Dockerized hosts), you cannot enter values that exceed these limits. If you leave these fields empty, the administrator's limits (if set) are used. If the administrator reduces the project limits to a value below after you have configured your settings, your settings are automatically reset to the new limits. Name. The name of the elastic Dockerized load generator. By default, these are named DOCKER1, DOCKER2, and DOCKER<n+1> equivalent to the number of Dockerized load generators that you want to provision. No. of related groups. The number of Vuser groups to which the load generator is assigned. If a load generator has been assigned to groups, you can click to display the related groups list or to unassign groups.

   3. Click Apply Assignment to add the selected load generators to the selected Vuser groups.

      Note: This is available only when at least one unassigned load generator and one group have been selected.

3. Select the groups to use in the test

   In the Groups pane, select the groups to which you want to assign load generators. You can use to search the list of groups by name.

   

4. Specify the load generators to assign to the groups

   1. In the Load Generators pane, select the load generators you want to assign to the selected groups from the load generator types (see About load generators).

      You can use to search the list of load generators by name or attributes. The number of each load generator type already assigned to the Vuser group are displayed adjacent to the load generator type tab.

      

      Note:  

      • The Elastic Cloud tab is displayed only if the project has been linked to a cloud account. For details, see Cloud accounts.

      • The Elastic Docker tab is displayed only if the project has been linked to an orchestrator. For details, see Automatic provisioning of Docker hosts.

      • You can add additional automatch or elastic load generators to the list by clicking Add LGs , and entering the number of additional load generators required for the test. You can also update load generator properties by clicking the Properties link. For details, see Manage load generator types.

   2. Select the checkbox for each load generator you want to assign to the selected groups.

      To select all load generators in the column, select the checkbox next to the Name column heading.

      Note: While hosts from older installations of LoadRunner Enterprise (up to three versions earlier) are still supported and are colored orange, we recommend upgrading them to the current LoadRunner Enterprise version before using them. Versions displayed in red are no longer supported and cannot be used to run tests.

   3. Click Apply Assignment to assign the selected load generators to the selected groups in the test.

      Conversely, if you want to unassign load generators from a group, clear the checkbox for each load generator you want to unassign, and click Apply Assignment.

   4. Click Save Test to save your settings.

   5. To view all load generators assigned to a group, select the group in the Groups pane, and in the group details pane on the right, select the Load Generators tab. The grid displays the name and load generator type, and the number of groups to which the load generator is assigned.

   6. If you want to unassign load generators from groups or replace them with other load generators, select the groups and load generators that you want to change, and select Unassign or Replace with another LG.

   7. If you want to unassign load generators from groups, select the groups and load generators that you want to unassign, and select Unassign.

   8. If you want to replace load generators with other load generators, select the groups and load generators that you want to change, and select Replace with another LG. In the Replace Load Generators dialog box, select the load generators you want to assign to the selected groups.

5. Select properties for the automatch load generators - optional

   You can select properties for the automatch load generators that are assigned to Vuser groups in your test. Properties include a location and other attributes. At runtime, each automatch load generator is matched up with an available specific load generator (in the host pool of the project) with the same properties.

   1. To select properties for automatch load generators, select More > LG Management to open the Load Generator Management dialog box.

   2. Select one or more automatch load generators for which you want to define the same settings, and enter a location and/or host attributes.

      You can also use to copy properties from one automatch load generator, and to paste them to multiple automatch load generators.

      To see the updated properties for an automatch load generator, you need to clear the checkbox, and then select it again.
      

   For more details, see Manage load generator types.

   Note: If no properties are specified, the automatch load generator is matched up with any load generator in the project's host pool.

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Manage load generator types

You can manage the different load generators types that are available to use in your performance test from the Load Generator Management dialog box.

To access the Load Generator Management dialog box:

1. In LoadRunner Enterprise, click Open the navigation toolbar and select Test Management (under Testing).

2. Select a performance test in the test management tree and click Edit Test.

3. In the Performance Test Designer window, click Groups and Workload.

4. On the Groups pane toolbar, click More > LG Management.

   Note:  

   • To select multiple load generators, click a row and drag the mouse to highlight the load generators you want to select. To select all load generators in the column, select the checkbox next to the Name column heading, or press CTRL + A.

   • Click to copy load generator properties from the selected load generator, and paste them to other load generators.

Configure load generator types

You can perform the following actions on the different load generator types from the Load Generator Type tab:

LG Type	Action
Specific	Click Enable RDP to enable remote desktop sessions. For details, see Configure RDP settings. Click Enable Terminal Services to enable terminal services. For details, see Configure Terminal Services settings. Note: Properties for specific load generator types are defined by the LoadRunner Enterprise administrator, and are read-only.
Automatch	Enables you to add additional automatch load generators to the test and define their properties. Click Add LGs and enter the number of load generators in the adjacent box. Click Add and define the following properties for automatch load generators: Name. The name of the automatch load generator. By default, these are named LG1, LG2, and LG<n+1> equivalent to the number of automatch load generators provisioned. To select all load generators in the list, select the checkbox next to the Name heading. Location. Choose a load generator location for the selected load generators. Host Attributes. You can customize the list of attributes. For details, see Customize load generator attributes.  Example: You want a Vuser group to use a load generator that is located in London and has medium strength and memory. Under Location, select London, and in the Host Attributes list, select Host memory: Medium and Host strength: Medium. At runtime, the system tries to assign a specific load generator with these properties to the Vuser group. Enable RDP. For details, see Enable RDP. Enable Terminal Services. For details, see Configure Terminal Services settings. At runtime, a specific load generator in the host pool of the project matching these properties is assigned to the Vuser group. When you select one or more automatch load generators, all the load generator details are displayed in the right pane.
Elastic Cloud	Enables you to add additional elastic cloud load generators to the test. Click Add LGs , and select the load generators and the number of each that you want to add. You can filter the list of load generators displayed in the grid by account, location, size, and/or operating system. Click Add to add the selected load generators and close the dialog box, or Add & Another to add and keep the dialog box open enabling you to add additional cloud load generators. The following information is displayed: Name. By default, cloud load generators are named CLOUD1, CLOUD2, and CLOUD<n+1>, equivalent to the number of cloud load generators provisioned. For task details, see Assign elastic hosts to a test. Template Name. Name used to identify the template. OS. Operating system of the cloud load generator. Location. Geographic location in which the cloud load generator is provisioned. Account. Cloud provider from which the load generator is provisioned (Amazon Web Services or Microsoft Azure). Size. The hardware configuration of the machine to be provisioned. This impacts the storage and memory. You can also delete cloud load generators from the list by selecting them, and then clicking Delete. For more on elastic cloud load generators, see Provision elastic cloud load generators.
Elastic Docker	Enables you to add additional elastic Dockerized load generators Click Add LGs and enter the number of load generators in the adjacent box. Click Add. The Dockerized load generators are added to the list with the name DOCKER1, DOCKER2, and DOCKER<n+1>, equivalent to the number of Dockerized load generators provisioned. For task details, see Assign elastic hosts to a test. For more on elastic Dockerized load generators, see Automatic provisioning of Docker hosts.

Configure RDP settings

You can perform the following actions from the RDP settings tab:

Enable RDP

To support GUI testing, you can run Vusers in an interactive RDP session. Select this option to enable remote desktop sessions for the selected Specific, Automatch, or Elastic Cloud load generator types. For task details, see Run Vusers in an interactive RDP session. Note: Interactive RDP mode is not supported when a LoadRunner Enterprise host is used simultaneously as a Controller and load generator. RDP mode is not supported for a local system user account. While a performance test with a system account runs for a load generator set to RDP mode, it does not open an interactive RDP session.

Select Color depth and resolution

Select the required color depth and resolution to be used to create the RDP session on the hosts running the script (the graphic card of the hosts running the script determines the default color depth and resolution if it does not support the selected one).

Configure Terminal Services settings

You can perform the following actions from the Terminal Services settings tab:

Enable Terminal Services	Enables you to configure terminal services sessions for the selected Specific, Automatch, or Elastic Cloud load generator types. For task details, see Configure terminal sessions.
No. of Terminal Services to open on Load Generator	Enter the number of terminals in your performance test. Note: You must open a terminal session for each terminal on which you want to run Vusers during the performance test.
Max. number of Vusers to run in a Terminal Service	Enter the maximum number of Vusers that you want to run in a terminal session. Note: The maximum number of Vusers depends on the Vuser type used in the script. For GUI Vusers, the maximum is one Vuser for each terminal session.
Create new session	Enables the Controller to launch terminal sessions automatically using the Remote Desktop Connection. When choosing this option (the default setting) you must specify the credentials required for automatic login: User Name, Password, and Domain. If you are using a custom user account, make sure you follow Run terminal sessions with a custom user account. Bit Level. You can also select the color depth of the session (15, 16, 24, or 32-bit level).
Connect to existing session	Enables a connection to an existing (open) terminal session. If you select this option, you must open a terminal client session manually for each terminal that you want to run Vusers on during the test run.

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Assign elastic hosts to a test

Using Elastic Cloud and Elastic Docker hosts automates the testing process by provisioning and de-provisioning hosts on demand, and seamlessly adds them to tests on the fly without having to reserve resources in advance.

1. Prerequisites

   • To assign Elastic Cloud hosts to a test, a cloud account must have been set up for provisioning load generators. For details, see Provision elastic cloud load generators.

   • To assign Elastic Docker hosts to a test, the project must be linked to an orchestrator (performed by your LoadRunner Enterprise administrator). For details, see Set up Dockerized hosts.

2. Select a test

   In LoadRunner Enterprise, click Open the navigation toolbar and select Test Management (under Testing). Select a performance test in the test management tree, and click Edit Test.

3. Assign elastic cloud-based or Dockerized load generators to Vuser groups

   Follow the steps in Distribute load generators among Vuser groups, and assign Elastic Cloud or Elastic Docker load generators to the groups for the test.

4. Set the post run action to collate results (if your LoadRunner Enterprise administrator did not set a post run action)

   To ensure that run results are not lost after a performance test ends (since elastic hosts are freed immediately after the run finishes), we recommend you select Post Run Action to Collate Results. For details, see Post Run Action.

5. Run the performance test

   Save and then run the test to check its performance. For details on running a test, see Run performance tests.

   When the test has finished, the elastic hosts are automatically removed from the test.

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See also:

• Define test workloads