Normally, when a test fails to execute or is aborted, a brief error message will be displayed in the Test Result Window. For a Web test that completes with error(s), detailed information can be found in the Web Test Playback window. For a load test completes with error(s), the errors are written to the Errors table, Tests table, and sometimes also the Requests table. Under certain (rare) conditions, it is difficult to find out why VSTS or the system does not behave as expected based on the given error messages and you may turn on VSTS tracing.

If you are running test locally, enable logging for the VSTestHost process.

1.     Open <Program Files>\Microsoft Visual Studio 9.0\Common7\IDE\VsTestHost.exe.config file.

2.     Add the following system.diagnostics section.

<system.diagnostics>

    <trace autoflush="true" indentsize="4">

        <listeners>                   

           <add name="myListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="c:\VSTestHost.log" />

        </listeners>

    </trace>

    <switches>

        <!-- You must use integral values for "value".  Use 0 for off, 1 for

             error, 2 for warn, 3 for info, and 4 for verbose. -->

        <add name="EqtTraceLevel" value="3" />

    </switches>

  </system.diagnostics>

3.     Specify the path to the log file and the trace level.

If you are running test on Rig, enable logging for the Agent and/or Controller processes.

1.     Under <Program Files>\Microsoft Visual Studio 9.0 Team Test Load Agent\LoadTest\, find QTAgent.exe.config for Agent process and QTController.exe.config for Controller process.

2.     In the config file, under appSettings section, locate line <add key="CreateTraceListener" value="no" />, and  change the value from “no” to “yes”.

3.     After you modify the config files, you need to restart the Controller and Agent.