When a piece of software built against OpenMPI fails, I will see an error referring to the rank of the MPI task which incurred the failure. For example:
MPI_ABORT was invoked on rank 1236 in communicator MPI_COMM_WORLD
with errorcode 1.
Unfortunately, I do not have access to the software code, just the installation directory tree for OpenMPI. My question is: Is there a flag that can be passed to mpirun, or an environment variable set, which would reveal the mapping of ranks to the hosts they are on?
I do understand that one could have multiple MPI ranks running on the same host, but finding a way to determine which rank ran on what host would go a long way in help troubleshooting problems which may be central to the host. Thanks!