Cost of creation/deletion of comm groups in MPI

Cost of creation/deletion of comm groups in MPI

I'm using MPI to run a simulated environment on a linux cluster. I'm
planning to move from a grid-based interest management to an aura-based
one. However, after doing some research, it seems like I would have to
create/destroy a lot comm groups pretty often (and there would be a high
number of comm groups).
So I'd like to know more about the cost of the creation/deletion of comm
groups and what is actually happening when I create a comm group? I'm
using OpenMPI on a RHEL EC2 cluster.