You need a way for your process to exchange information so MPI_Init() can work.
One option is to have your custom launcher implement a PMIx server https://pmix.github.io If you choose this path, you will likely want to use the Open PMIx reference implementation https://openpmix.github.io so your custom launcher would "only" have to implement a limited number of callbacks. Cheers, Gilles ----- Original Message ----- Any pointers? On Tue, Jan 25, 2022 at 12:55 PM Ralph Castain via users <users@lists. open-mpi.org> wrote: Short answer is yes, but it it a bit complicated to do. On Jan 25, 2022, at 12:28 PM, Saliya Ekanayake via users <users@lists. open-mpi.org> wrote: Hi, I am trying to run an MPI program on a platform that launches the processes using a custom launcher (not mpiexec). This will end up spawning N processes of the program, but I am not sure if MPI_Init() would work or not in this case? Is it possible to have a group of processes launched by some other means to be tied into an MPI communicator? Thank you, Saliyaf -- Saliya Ekanayake, Ph.D Cloud Accelerated Systems & Technologies (CAST) Microsoft
