Vusers in LoadRunner

Vusers emulate the actions of human users by performing typical business processes in your application. The actions that a Vuser performs during the recording session are described in a Vuser script.

HP’s tool for creating Vuser scripts is the Virtual User Generator, VuGen. You use VuGen to develop a Vuser script by recording a user performing typical business processes on a client application. VuGen records the actions that you perform during the recording session, recording only the activity between the client and the server. Instead of having to manually program the application’s API function calls to the server, VuGen automatically generates functions that accurately model and emulate real world situations.

During recording VuGen monitors the client end of the database and traces all the requests sent by the user and received from the user, to the server.

During playback, Vuser scripts communicate directly with the server by executing calls to the server API. When a Vuser communicates directly with a server, system resources are not required for the client interface. This lets you run a large number of Vusers simultaneously on a single workstation, and enables you to use only a few testing machines to emulate large server loads.

In addition, since Vuser scripts do not rely on client software, you can use Vusers to check server performance even before the user interface of the client software has been fully developed.

Using VuGen, you can run scripts as standalone tests. Running scripts from VuGen is useful for debugging as it enables you to see how a Vuser will behave and which enhancements need to be made.

VuGen enables you to record a variety of Vuser types, each suited to a particular load testing environment or topology. When you open a new test, VuGen displays a complete list of the supported protocols.

While running the Vusers, you gather information about the system’s response. Afterwards, you can view this information with the Analysis tool. For example, you can observe how a server behaved when one hundred Vusers simultaneously withdrew cash from a bank’s ATM.

Also See: Other LoadRunner Tutorials