Answered question

We want to test a specific function on our web app. But the user must be authenticated before they can reach that page.

We want to test how many users can hit that specific function and how long it takes to complete their requests.

We don’t want the login process to be part of the timings. ie we want them all to have successfully passed authentication, and then to all start hitting the function at exactly the same time.

How can we authenticate them all before the measurement starts, so that we just measure the performance of that one function (and don’t cloud the figures with varying login response times too)?

In a simple world we would just like them all to authenticate and then wait until everyone has been authenticated. Then (and only then) the virtual users would all request the function at exactly the same time.