Multithreading

Multithreading:

In Loadrunner we have two options under Multithreading in Runtime settings.

1.      Run Vuser as process

2.      Run Vuser as thread

If Run Vuser as thread is selected, Multithreading is enabled.

Benefits of Multithreading – Helps to run more number of vusers per load generator.

The contoller uses a driver program ie mdrv.exe or r3vuser.exe to run vusers.
If we run vuser as thread, the contoller launches only one driver program for every 50 users. 50 Vuser is default setting.

If we run each vuser as a process, Multithreading is disabled and it launches drivers program in to memory again and again for every instance of vuser. This uses large amount of RAM and other system resources.

How to find which protocol is threadsafe?
Except for Sybase-Ctlib, Sybase-Dblib, Informix, Tuxedo and Peoplesoft-Tuxedo protocols, all other protocols are threadsafe.

Using VuGen:

Launch VuGen.

Select File->New.

Select a protocol and cancel recording.

Go to Vuser->Runtime Settings->Miscellaneous.

If the protocol is threadsafe, under Multithreading we have both the options enabled as shown below.

Protocol selected is Web(HTTP/HTML).

If the protocol is not threadsafe, under Multithreading we have only one option enabled as shown below.

Protocol Selected is Tuxedo.

Here Run Vuser as thread is disabled.

Another way to find threadsafe without opening VuGen:

We can check each protocol as follows to findout whether it is threadsafe or not.

1. Go to ...\LoadRunner\dat\protocols folder
2. Open up an appropriate .lrp file (i.e. http.lrp, TUXEDO.lrp, TUXEDO63.lrp)
3. Search for "EnableThreads". If this parameter value is set to 1 then it is threadsafe else it is not.
    For example: HTTP has EnableThreads=1
                          Tuxedo has EnableThreads=0