How to Run the Exchange Load Generator Test


Topic Last Modified: 2007-03-14

A typical test that has an average number of users is set to take ten hours as the duration of the simulation. Allow for at least two hours for a sufficient warm-up. After this warm-up period, the clients and the server operate at a sustained baseline because the intensive startup processes have completed. After the server starts and code is paged into memory, the server operates in a consistent pattern. If the mailbox store database is new, more database activity can occur as index pages split. The server does not reach a sustained baseline for adequate benchmarking until this activity level decreases.

You should collect test information when the server is in this consistent state. After the server has reached a sustained baseline, it must run long enough to collect statistically significant data. The time this takes depends on the complexity of the user model and the cumulative rate at which user actions are being generated. Perform a long calibration test run before you run your actual tests. For example, if you perform an eight-hour test run and find variation from hour to hour, but not between two-hour segments, the results are consistent. This indicates that your test runs should include at least two hours where the server has reached a sustained baseline of consistent behavior.

For information about performance counters and running Performance Monitor (Perfmon) so that you can monitor the progress of the simulation, see Performance Counters Reference.

  1. Start Exchange Load Generator. For the three methods to start the test, see How to Start Exchange Load Generator.

  2. Log on to the client computer that has domain credentials. If you have not joined the client computer to a domain, log on with a local administrator account. We recommend that you use a domain account because the user experience will be enhanced.

  3. Open a command shell and locate the Exchange Load Generator installation directory.

  4. Run the command LoadGenCmd.exe /r /c <configurationfile>, where configurationfile is the name of your configuration file. By default, this is LoadGenConfig.xml in the current directory. If you have not renamed your configuration file, you only need to run LoadGenCmd.exe /r.

    To view detailed trace information about the actions that the tool is performing, you can add a "trace listener" as a command-line option. Trace listeners can be either files or the console, if you want to view the output on screen. To view the output on screen, add this option to the command line: /add console. To output to a file that is named trace log, add this option to the command line: /add trace.log.
  5. For running a test using the user interface, after you have opened the user interface, follow the instructions on the Welcome page to Start a new test.


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