TN3270 performance testing guidelines

Before you can test the performance of TN3270 terminal applications, set up your test environment and incorporate these guidelines to produce reliable performance tests.


You can use this extension to test applications that run on a TN3270 terminal emulation client, where the test simulates multiple terminals that connect to one or several servers.

These TN3270 terminal emulation packages are supported:
  • IBM® Personal Communications
  • Attachmate EXTRA! X-treme


When deploying your performance tests, use a relevant number of virtual users on a given computer. For example, if you deploy too many virtual users on a single computer, the results reflect more the load of the test computer than the load of the server.

For best results with performance tests on an average test computer with a 1 GHz processor and 1 GB of RAM, do not exceed 1000 concurrent virtual users.

If you exceed the number of virtual users that a single test computer can run, the measured performance of the server is affected by the performance of the test computer, which invalidates the final results.

When editing a schedule for long performance tests, use these recommendations:
  • In the schedule editor, reduce the Test log level setting to None.
  • In the schedule editor, set the Statistics sample interval value to approximately 1/60 of the run time, for example 12 minutes for an estimated 12-hour session.
  • When possible, use loops inside test suites rather than loops in the schedule. Using loops inside test suites avoids connection problems that might occur over long-duration tests and emphasizes measurement of the send and receive activity rather than connection and close activity.