1)Simultaneous and Concurrent users:
All the vusers in a particular scenario are called Concurrent vusers. They may or may not perform the same tasks.Concurrent users hit the site at exactly the same moment. Concurrent users are the users who have a valid session in the server & they are performing the same operation at any point of time. All the concurrent users would perform login, reports download, etc at the same point of time
Simultaneous vusers is more to do with rendezvous points. When we set rendezvous points we instruct the system to wait till a certain no of vusers arrive so that they all can do a particular task simultaneously. These vusers performing the same task at the same time are called Simultaneous vusers. Simultaneous users have active connections to the same Web site. Simultaneous users are the users who have a valid session in the server. Each of the users would be performing different actions like one doing login , other viewing the reports, etc.
2) Vugen And Controller:
VuGen is a loadrunner component used to generate vuser script i.e here we record a business operation performed by a single user. The Vugen records the behavior of the client s/w, and automatically generates a script that can be used by the controller to run vusers. VuGen generates a script that contains the actual values used during recording and during script enhancement phase test engineer has to replace the recorded values with parameters is known as parameterizing the script.
The Controller has two sections
- Design Section – Used to design the load testing scenario
- Run Section – Used to monitor scenarios which are in execution.
- Sometime, after creating a script, a simple playback fail even though the recording of the same actions succeeded.
- Many applications use dynamic values that change each time you use the application. For example, some servers assign a unique session ID for every new session. When you try to replay a recorded session, the application creates a new session ID that differs from the recorded session ID.
- LoadRunner addresses this issue through correlation. Correlation saves the changing values to a parameter.When running the emulation, the Vuser does not use the recorded value—instead, it uses the new value assigned to it by the server.