Strategies for troubleshooting test controllers and test agents in load tests

Applies to: yesVisual Studio noVisual Studio for Mac

This article covers some common problems you might encounter when you work with test controllers and test agents in Visual Studio.

Note

Web performance and load test functionality is deprecated. Visual Studio 2019 is the last version where web performance and load testing will be fully available. For more information, see the Cloud-based load testing service end of life blog post. To reduce the impact on users some minimum support is still available in Visual Studio 2022 Preview 3 or later. Users should also note web performance and load test functionality only supports Internet Explorer which is not available on Windows 11 and some versions of Windows 10. Read more on Internet Explorer Lifecycle policy.

Unable to collect performance counters on test agent computer

When you run a load test, you might receive errors when you try to connect to a test agent computer and collect performance counters. The Remote Registry service is the service responsible for providing performance counter data to a remote computer. On some operating systems, the Remote Registry service does not start automatically. To fix this problem, manually start the Remote Registry service.

Note

You can access the Remote Registry service in Control Panel. Choose Administrative Tools and then choose Services.

Another cause of this problem is that you do not have sufficient permissions to read performance counters. For local test runs, the account of the user who is running the test must be a member of the Power Users group or higher, or be a member of the Performance Monitor Users group. For remote test runs, the account that the controller is configured to run as must be a member of the Power Users group or higher, or be a member of the Performance Monitor Users group.

Set the logging level on a test controller computer

You can control the level of logging on a test controller computer. This is useful when you are trying to diagnose a problem when you are running a load test on an environment.

To set the logging level on a test controller computer

  1. Stop the test controller service. At a command prompt, type net stop vsttcontroller.

  2. Open the file QTController.exe.config. This file is located in the controller installation directory.

  3. Edit the entry for the EqtTraceLevel switch in the system diagnostics section of the file. Your code should resemble this:

    <system.diagnostics>
        <trace autoflush="true" indentsize="4">
            <listeners>
                <add name="myListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="d:\VSTestHost.log" />
            </listeners>
        </trace>
        <switches>
            <!-- You must use integral values for "value":
                    0 = off,
                    1 = error,
                    2 = warn,
                    3 = info,
                    4 = verbose. -->
            <add name="EqtTraceLevel" value="4" />
        </switches>
    </system.diagnostics>
    
  4. Save the file.

  5. Start the controller service. At a command prompt, type net start vsttcontroller.

This applies to the test controller, the test agent service, and the test agent process. When diagnosing problems, it is helpful to enable logging on all three processes. The procedure to set the logging level is the same for all three processes, as specified earlier for the test controller. To set the logging levels for the test agent service and the agent process, use the following configuration files:

  • QTController.exe.config Controller service

  • QTAgentService.exe.config Agent service

  • QTDCAgent(32).exe.config Agent data adapter process for 32-bit architecture.

  • QTDCAgent(64).exe.config Agent data adapter process for 64-bit architecture.

  • QTAgent(32).exe.config Agent test process for 32-bit architecture.

  • QTAgent(64).exe.config Agent test process for 64-bit architecture.

Bind a test controller to a network adapter

When you try to set up a test agent, you might receive the following error:

Error 8110. Cannot connect to the specified controller computer or access the controller object.

This error can be caused by installing the test controller on a computer that has more than one network adapter.

Note

It is also possible to install test agents successfully, and not see this problem until you try to run a test.

To fix this error, you must bind the test controller to one of the network adapters. You have to set the BindTo property on the test controller, and then change the test agent to refer to the test controller by IP address instead of by name. The steps are provided in the following procedures.

To obtain the IP address of the network adapter

  1. Choose Start, and then choose Run.

    The Run dialog box is displayed.

  2. Type cmd and then choose OK.

    A command prompt opens.

  3. Type ipconfig /all.

    The IP addresses for your network adapters are displayed. Record the IP address of the network adapter that you want to bind your controller to.

To bind a test controller to a network adapter

  1. Stop the test controller service. At a command prompt, type net stop vsttcontroller.

  2. Open the file QTController.exe.config. This file is located in %ProgramFiles(x86)%\Microsoft Visual Studio\2017\Enterprise\Common7\IDE.

  3. Add an entry for the BindTo property to the application settings. Specify the IP address of the network adapter that you want to bind the controller to. Your code should resemble this:

    <appSettings>
        <add key="LogSizeLimitInMegs" value="20" />
        <add key="AgentSyncTimeoutInSeconds" value="120" />
        <add key="ControllerServicePort" value="6901" />
        <add key="ControllerUsersGroup" value="TeamTestControllerUsers" />
        <add key="ControllerAdminsGroup" value="TeamTestControllerAdmins" />
        <add key="CreateTraceListener" value="no" />
        <add key="BindTo" value="<YOUR IP ADDRESS>" />
    </appSettings>
    
  4. Save the file.

  5. Start the test controller service. At a command prompt, type net start vsttcontroller.

To connect a test agent to a bound controller

  • Run the test agent installation again. This time, specify the IP address for the test controller instead of the test controller name.

This applies to the test controller, the test agent service, and the test agent process. The BindTo property must be set for each process that is running on a computer that has more than one network adapter. The procedure to set the BindTo property is the same for all three processes, as specified earlier for the test controller. To set the logging levels for the test agent service and the test agent process, use the configuration files that are listed in Set the logging level on a test controller computer.

See also