Modify load test logging settings
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
The load test result for the completed load test contains performance counter samples and error information that was collected in a log periodically from the computers-under-test. A large number of performance counter samples can be collected over the course of a load test run. The amount of performance data that is collected depends on the length of the run, the sampling interval, the number of computers under test, and the number of counters to collect. For a large load test, the amount of performance data that is collected can easily be several gigabytes; therefore, you might consider modifying how often data is saved to the log. See Test controllers and test agents.
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.
The test controller spools all collected load test sample data to a database log while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes.
| Task | Associated topics |
|---|---|
| Save logs if a load test fails: You can specify if you want to save the test log whenever a load test fails. | - How to: Specify if test failures are saved to test logs |
| Set the maximum file size for the log file: You can edit the XML configuration file that is associated with the test controller service to specify the maximum file size you want to use for the log file. | Modify <add key="LogSizeLimitInMegs" value="20"/> in the QTCcontroller.exe.config XML configuration file. |