When using Matlab engine and calling from multiple ranks, does each rank use one Matlab license?

I'm trying to write a python code that will call a Matlab function compiled for python. I need to know if, when running this code using multiple MPI processes, will each need one instance of Matlab? Will this be a potential bottleneck in opening multiple instances of Matlab?

Answer 1

[Divyanshu]

Hi Dan,

As per my understanding you are trying to call MATLAB functions from Python Code. If you are running the Python code from multiple processes and are trying to connect each Python session with an instance of MATLAB, it is possible to do so.

Please refer the following documentation link for more details on 'How to connect Python to a Running MATLAB session on your local machince':

https://www.mathworks.com/help/matlab/matlab_external/connect-python-to-running-matlab-session.html

You may replicate the steps specified in the above documentation to multiple Python sessions.

Hope it helps!

[Dan Houck]

I think this partially answers the question. I work at a large institution and I don't know the specifics of our licensing arrangement. I'm worried that we could hit a license limit if each instance of Matlab requires one license. Does anyone know if that's the case or not? As a related question, can anyone speculate on how slow it will be to have to open an instance of Matlab each time the Matlab function compiled for python is called?

[Divyanshu]

Hi, I don't think you will hit any such license limit because running Multiple sessions/instances of MATLAB on same machine under the same user account does not consume multiple licenses.

You can refer the following thread for more details:

https://www.mathworks.com/matlabcentral/answers/2080371-do-multiple-instances-of-matlab-on-the-same-computer-take-up-more-than-one-seat