How to spread VUsers across multiple test agents w

Question

I'm trying to run a load test in visual studio 2015. I have 1 test controller with 3 test agents setup. I have set the weighting of the agents to 33 each as I would like to spread the userload evenly across them. When I run the test I see evidence that it tries log in with the same user on all 3 agents, and as the tests are running I'm observing that there is 1 successfull login and 2 failed / user, which I assume is happening because they all try to log in at once.

How can I make sure that 1 Vuser is assigned to one agent only? (1 agent can have multiple users of course)

Answer 1

Set the Access method property of the data source to Unique. See here for more details. In brief, for the Sequential and Random access methods a full copy of all of the data is sent to each agent. For Unique the data is split into pieces and each agent gets one piece, thus maintaining the desired "use each data value only once".