How can i integrate several different users into one test script?

[Peter Brandt-Erichsen <pb...@adsl.intergate.ca>]

Hey Folks,

I have designed a quick and dirty test suite using JMeter 2.0.3 that
tests my web application by performing a login based on form authentication 
and then proceeds to click every link in the application at least once.

The plan is to use this test to get a baseline measurement of the performance
of the application and then use this measurement to compare against more
sophisticated test suites planned for the future.

The problem i am encountering is this.

I am using a User Defined Variables node to describe the username/password
of one user, and then using this information for the login step in the test suite.

This works for a single thread test run, but if i increase the number of threads,
i am concerned that i am creating an artificial test case, since the same user
account is being shared over multiple threads which creates a scenario where
the same user is logging in concurrently.

It would be more realistic if each thread is associated with a distinct user with a 
unique username/password combination.

This is also causing problems with deadlock issues in my EJB layer since each
thread is accessing the same User bean, and this in turn causes timeout issues
when i try to scale up the Requests per Second and/or the number of threads.

Is there a way for me to build a list of user accounts (username/password), in a file
perhaps?, and have each thread access this list in a sequential or random way at 
the start of an iteration, such that each thread is associated with a different user 
account?

Any help on this would be greatly appreciated !

Cheers
Peter