varFDTD solver using MPI


#1

Hello

I would like to simulate MMI using varFDTD solver.
I have total 15 varFDTD engine so I want to use these cores for faster simulation.
My question are like below.

  1. I have used below command since I want to simulate with 10 cores. However, in FlexNet license server, it seems that only 1 license has been caught.

mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_175.lms

Are they working together? Or, has only one engine been caught for simulation?

  1. If I run code like below, I want to know if each lms file would be saved.
    If not, is there any command for saving each lms file?

mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_175.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_180.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_185.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_190.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_195.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_200.lms

Let’s talk about this.


#2

Hi Youngkwan Jo,

Allow me to clarify the license usage. Our current licensing model allows 1 license per user, per computer/node.

So if you are running multiple simulations on 1 computer and logged in only as 1 user account. Then even if you are running several instances of the engine, it will only take up 1 engine license from your license manager. But it will utilize the number of processes/cores you specified on your resource configuration. The number of cores in a computer/node does not affect the number of licenses being used as long as it is from one computer/node.

The number of licenses being checked out will be affected if you are logged into 10 computers and using these 10 computers to run simulations, then you will need 10 engine licenses.

To view the actual running engines on your machine, you will have to open you Take Manager (on Windows) and check the performance tab to see the CPU or Core utilization for each of the engines, as shown in the example below using 4 processes or virtual cores.

  • When you run the code as per your post:

If I run code like below, I want to know if each lms file would be saved.
If not, is there any command for saving each lms file?
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_175.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_180.lms
mpiexec -n 10 varfdtd-engine-mpich2nem 20170616_1_10_185.lms

  • The above commands will run your simulations one at a time using 10 cores of your computer for each simulation, then after finishing the simulation it will move on to the next simulation until it will completely run all the simulations you provided in your code. This will only take up 1 engine license since it is running only one 1 computer.

Hope this information is helpful reference.

-Lito


#3

Thanks for your reply.

Then, is there any possible way or command to check engine usage on linux based system?

-Youngkwan


#4

Youngkwan,

I am not sure if this is what you are referring to:

  1. To check license availability or if the engine license is being checked out, we can do so by going to the FlexNet license manager dashboard where it is activated as shown on your first post.
  1. If you want to know if the engine is running on your system when you execute the command, you can do the following on a different terminal window:

top
while on the top screen,
press & hold shift key + M

  • This will arrange your top screen according to the application running the most amount of memory.
  • In the example above, I am running two instances of fdtd-engine on a Linux computer.

Hope this information helps.

-Lito