In VS 2010, we made several changes to the process models for local and remote execution.

These changes impact you when you:

1. Look in task manager or at performance counters to see how the test processes are running,
2. Turn on logging to debug a problem. You turn on logging in the .config file for the process you want to log from, so obviously the process name changes affect this.
3. Use other settings in the config files to control test execution or data collection.

Everyone working with load testing will probably do all three of these activities at some point or another.

A major new piece of infrastructure in VS 2010 is test data collectors, which give you the ability to collect data from the system under test. Some data collectors work against the test host process, and have to hook into the process before it starts (such as Intellitrace and Test Impact). To make this happen, we start the data collection process first, and give data collectors an opportunity to hook the test host process. Since the controller is orchestrating the test, for local execution we were required to move the controller out of the test host process and into devenv (Visual Studio).

Here are the changes in local execution:

The key changes here are:

1. The host process was renamed.
2. The local controller is now hosted in devenv rather than the agent process.
3. We have added a QTDCAgent.exe data collector process.
4. There is now an option to run tests in a 64 bit process on a 64 bit machine, or force tests to always run in a 32 bit process. The default is to force tests to run 32 bit, since Coded  UI tests will only run in a 32 bit process. If you are running load tests you should under most circumstances change this to Run tests in a 64 bit process on a 64 bit machine.

Here is the place in Test Settings you have to change for #4.

For remote execution, you can see things remain mostly the same as in VS 2008, except for the addition of the data collector agent and 32 bit flavors of the processes.

Ed.