When using a standard Thread Group, Blazemeter overrides the Thread Group's configuration of 'Threads', 'Iterations', 'Rampup' and 'Duration'. Unfortunately that is not the case when using an Ultimate/Stepping/Concurrency Thread Group.

In order for your scenario to work with the Ultimate/Stepping/Concurrency Thread Group, please configure Blazemeter’s test configuration page as follows:

1. Upload your JMeter script - Please note that this step must be done first in order to continue to the next step.
2. Uncheck Total Users. 
3. Uncheck Duration/Iterations.
4. Uncheck Ramp up Time.
5. Uncheck Ramp up Steps.

Multiple Engines Scenario

Please note that if you will try to run a multi engine test, e.g 2000 Concurrent Users, using 5 load engines, you will require to adjust the ‘Threads' values in your Ultimate/Stepping/Concurrency Thread Group to be 1/5 their current values. e.g set the Ultimate/Stepping/Concurrency Thread Group to load up to 400 threads. If not, each engine will run 2000 threads, which will eventually result in the crash of the engines or massive overload on your app server side - which ever comes first.

To configure the amount of engines, you should follow the process below.

1. Press on the current configured amount of engines
   
2. A pop-up box will appear - configure the desired amount of engines
   
3. Press any where outside the pop-up box, and the amount of engines configured will be updated
   

Want to learn more about running BlazeMeter tests? Watch our on-demand recording, How to Make JMeter Highly Scalable and More Collaborative With BlazeMeter