Understanding Load Tests

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Microsoft Visual Studio Team System Test provides a tool for creating and running load tests. The primary goal of a load test is to simulate many users accessing a server at the same time.

When you add Web tests to a load test, you simulate multiple users opening simultaneous connections to a server and making multiple HTTP requests. You can set properties on load tests that broadly apply to the individual Web tests.

When you add unit tests to a load test, you exercise the performance of non-Web based server components. An example application of a unit test under load is to test data access model components.

Load tests can be run using a set of test agents and a test agent controller. For more information, see Configuring Test Agents and Test Agent Controllers for Load Testing.

Load tests are used in several different types of testing:

Type of Testing



How your application performs under light loads for short durations.


To determine if the application will run successfully for a sustained duration under heavy load.


To determine how responsive your application is.

Capacity Planning

How your application performs at various capacities.

About Load Tests

Load tests consist of a series of Web tests or unit tests which operate under multiple simulated users over a period of time. Load tests are created with the Load Test Wizard. For more information about the Load Test Wizard, see How to: Specify Scenarios.

To change the load test properties, use the Load Test Editor. The properties allow you to run Web tests with different user profiles, browser targets, and load patterns. Test results are stored in SQL-based Load Test Results Repository. For more information, see Load Test Results Repository.

View your load tests as they run in the Load Test Monitor. To view load test results for completed test runs, use the Load Test Analyzer. For more information, see Analyzing Load Test Runs.


Load test files and load test results contain potentially sensitive information that could be used to build an attack against your computer or your network. Load tests and load test results contain computer names and connection strings. You should be aware of this when sharing tests or test results with others.

In This Section

About Scenarios

About Load Pattern

About Test Mix

About Browser Mix

About Network Mix

About Run Settings

About Think Times

About Validation, Extraction, and Threshold Rules

About SQL Tracing

See Also


About Counter Sets

About the Load Test Results Repository

Other Resources

Working with Load Tests