When using OpenMPI with Omni-Compiler
(https://github.com/omni-compiler/omni-compiler ), one gets errors when
trying to run in a cloud environment because Open MPI "greedily uses up
all IP addresses". Many cloud environments will offer a number of
interfaces. While the documentation on this is helpful:
https://www.open-mpi.org/faq/?category=tcp#tcp-multi-network
it may be worth making this information more prominent or changing the
default behaviour since at runtime the library does not restrict itself
to the IP addresses specified in the hostfile when using:
mpirun -np 2 -hostfile ./hostfile ./C_hello
and one needs to use:
mpirun -np 2 -hostfile ./hostfile --mca btl_tcp_if_include eth3 ./C_hello
