Introduction

Load tests run multiple instances of one or more unit tests so that you can measure your application's performance and ability to handle load. The primary components of a Visual Studio 2010 load test include:

• Scenarios – The section of a load test where you configure the test load pattern, test mix model, test mix, network mix and Web browser mix. Scenarios accommodate the complexity of simulating complex real world work load profiles. For a comprehensive listing of all load test scenario properties see Load Test Scenario Properties (http://go.microsoft.com/fwlink/?LinkId=208327).
• Counter Sets – The section of a load test where you create particular groupings or “Sets” of performance counters to be collected while the load test is running. Several predefined counter sets are provided by default and custom counter sets can be added. For example to evaluate Network performance you can create a custom counter set, add the relevant Network performance counters and save it to the list of available counter sets. For more information about creating and saving counter sets for load tests see Specifying the Counter Sets for Computers in a Load Test (http://go.microsoft.com/fwlink/?LinkId=208328).
• Run Settings – Run settings define multiple aspects of a load test, including the test duration, the counter sets that are associated with various computers during the load test, various test validation options, and test results storage options. You can create and store multiple run settings for each load test, and then select a particular setting to use when you run the test. An initial run setting is added to your load test when you create your load test with the New Load Test Wizard. For a comprehensive listing of all load test run setting properties see Load Test Run Setting Properties (http://go.microsoft.com/fwlink/?LinkId=208329).

Load tests are created using the New Load Test Wizard, edited with the Load Test Editor, and analyzed in the Load Test Analyzer. All these tools are included in Microsoft Visual Studio Ultimate edition. For more information about creating and editing load tests in Visual Studio 2010 Ultimate edition see Creating and Editing Load Tests (http://go.microsoft.com/fwlink/?LinkId=208308).

Follow the steps in the sections below to add a load test to the test project described in Create a Unit Test to Submit Documents to BizTalk Server. These steps also describe how to configure the Scenarios, Counter Sets, and Run Settings for a load test.

Add a Load Test and Configure the Load Test Scenario, Counter Sets, and Run Settings

This topic describes how to use the New Load Test Wizard to add a load test to a test project and how to configure the load test to meet specific needs.

Use the New Load Test Wizard to Add a Load Test to the Test Project

Follow these steps to add a load test to a test project using the New Load Test Wizard.

1. Open the Load Test solution in Visual Studio 2010 if it is not already open.
2. Add a folder to the BTSLoad project; this folder will contain any load tests that are created as part of this project. In Solution Explorer, right-click the BTSLoad project, point to Add, and click New Folder. A folder icon with the highlighted text NewFolder1 will appear under the BTSLoad project, type LoadTests to change the highlighted text and press the Enter key to complete creation of the folder C:\Projects\LoadTest\BTSLoad\LoadTests.
3. In Solution Explorer, right-click on the BTSLoad project, point to Add, and then click Load Test to start the New Load Test Wizard.
4. Click Next to display the Edit Settings for a Load Test Scenario page.
5. On the Edit Settings for a Load Test Scenario page under Enter a name for the load test scenario: type BTS_Messaging_Step. Under Think time profile select Do not use think times and then click Next to display the Edit load pattern settings for a load test scenario page.
6. On the Edit load pattern settings for a load test scenario page select Step load: and enter the following values:
   
   • Start user count: 30 users
   • Step duration: 60 seconds
   • Step user count: 10 users
   • Maximum user count 80 users
   
   

   Note

   When applying settings for a step load pattern you should calculate the amount of time required for all step increments to complete. For example, using the load pattern settings specified above the load test will need 5 minutes to complete all of the 60 second step increments when ramping up from 30 to 80 users. On the last page of the New Load Test Wizard you will be presented with options for specifying the length of the load test, one of which will be Load Test Duration. If you have already calculated the time required for all step increments to complete then it is a straightforward task to enter the value (5 minutes in this case) for Load Test Duration.

    

   Click Next to display the Select a test mix model for the load test page.
7. On the Select a test mix model for the load test page select Based on the number of virtual users and click Next to display the Add tests to the load test scenario and edit the test mix page.
8. On the Add tests to the load test scenario and edit the test mix page click the Add button to display the Add Tests dialog box.
9. Under Available tests: double-click BTSMessaging and BTSMessaging2 to add these unit tests to the list of Selected tests. Click OK and then click Next to display the Add network types to a load test scenario and edit the network mix page.
10. On the Add network types to a load test scenario and edit the network mix page verify that Network Type is set to LAN with a Distribution of 100% and click Next to display the Specify computers to monitor with counter sets during load test run page.
11. On the Specify computers to monitor with counter sets during load test run page click Next to display the Review and edit run settings for a load test page.
    
    

    Note

    Do not add computers to the load test at this time. The New Load Test Wizard will only allow you to associate computers with predefined counter sets, and this load test requires the use of both predefined and custom counter sets. After the wizard is complete and the load test is saved you can edit the load test to add custom counter sets and configure the load test to monitor computers using both predefined and custom counter sets.

    
    On the Review and edit run settings for a load test page enter the following values:
    
    1. Select Load test duration.
    2. Warm-up duration (hh mm ss): - 30 seconds
    3. Run duration (hh mm ss): - 5 minutes
       
       

       Note
       The time allocated for Run duration should equal the amount of time required for all step increments to complete as described in step 5 above, or 5 minutes for this example.

        

    4. Sampling rate: 5 seconds
    5. Description (optional), enter a description for the load test here.
    6. Save Log on Test Failure: True
    7. Validation level: Low – invoke validation rules marked low
12. Click Finish to close the New Load Test Wizard.
13. Click the File menu and select Save <Load Test Name>.loadtest As… to display the Save File As dialog box.
    
    

    Note
    In this example, <Load Test Name> will be the name assigned to the load test file by Visual Studio 2010, typically loadtestx.loadtest, unless the name of the file has already been manually changed.

     

14. Save the file to the C:\Projects\LoadTest\BTSLoad\LoadTests directory created earlier. It may be useful to save the file with the name used for the scenario, in this example the scenario name is BTS_Messaging_Step so the loadtest file would be saved as C:\Projects\LoadTest\BTSLoad\LoadTests \BTS_Messaging_Step.loadtest.

Add a Custom Counter Set to Measure BizTalk Server Key Performance Indicators (KPI)

Follow these steps to add a counter set with performance counters that measure BizTalk Server KPI required for determining Maximum Sustainable Throughput (MST) of the BizTalk Server application:

1. In Solution Explorer double-click the load test that you created in the previous section to view the load test in Load Test editor.
2. In Load Test editor, click to expand Counter Sets. Notice that there is no predefined counter set for BizTalk Server, therefore a custom “BizTalk Server” counter set must be added to the list of counter sets.
3. Right-click Counter Sets and select Add Custom Counter Set. By default this action will create a custom counter set with the name Custom1.
4. Right-click the Custom1 counter set and select Properties to set focus to the Properties dialog for the Custom1 counter set.
5. Double-click the name Custom1 in the Properties dialog, type BizTalk and then press the Enter key to rename the custom counter set to BizTalk.
6. In Load Test Editor, right-click the BizTalk counter set and select Add Counters to display the Pick Performance Counters dialog box.
7. Under Computer:, type the name of one of the BizTalk Server computers in the BizTalk Server group to display performance monitor categories that include BizTalk Server performance counters.
   
   

   Important

   To ensure that all BizTalk Server performance categories and performance counters are listed, you may need to type in the fully qualified domain name (or IP Address) of a BizTalk Server in the group and you may also need to start the instances of the following hosts on the BizTalk Server computer: Instances of BizTalk hosts which are bound to orchestrations that will run during the load test. Instances of BizTalk hosts configured as send or receive handlers for adapters that will run during the load test.

    

8. BizTalk Server provides quite an extensive set of performance counters. For purposes of determining the Maximum Sustainable Performance (MST) of a BizTalk Server application you only need to add the following BizTalk Server performance counters to the BizTalk custom counter set:
   

   Performance Category	Performance Counter
   Processor	% Processor Time for the _Total counter instance.
   BizTalk:Message Box: General Counters	Spool Size for the <BizTalk MessageBox database name>:<SQL Server instance name> counter instance. Note <BizTalk MessageBox database name> and <SQL Server instance name> are just placeholders for the actual names of the BizTalk MessageBox database and the SQL Server instance that houses the BizTalk MessageBox database. These placeholders should be replaced with the actual names of the BizTalk MessageBox database and associated SQL Server instance.
   BizTalk:Messaging	Documents received/Sec for the receive host counter instance. Documents processed/Sec for the transmit host counter instance.
   BizTalk:Message Agent	Message delivery incoming rate for the document receive host.
   BizTalk:Message Agent	Message publishing outgoing rate for the document transmit host.
   XLANG/s Orchestrations	Orchestrations completed/sec for the Orchestration processing host.

Modify Run Settings to Specify the Computers to Monitor with Counter Sets

Follow these steps to associate the appropriate counter sets with the appropriate computers for the load test:

1. In Load Test Editor, Right-click Run Settings and select Manage Counter Sets to display the Manage Counter Sets dialog box.
2. Click Add Computer to add a new computer to the list. An icon with the highlighted text New Computer will appear under Computers and counter sets to monitor:. Replace the highlighted text by typing the name of the computer you would like to add to the list. 
3. After adding the computer to the list, click to expand the list of available counter sets and then click to select one or more of the available counter sets to associate the counter set(s) with the computer.
4. Repeat steps 2 and 3 until you have associated counter sets with all computers for which you would like to collect performance data.

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See Also

Another important place to find a huge amount of BizTalk related articles is the TechNet Wiki itself. The best entry point is BizTalk Server Resources on the TechNet Wiki.

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