In this slidecast, Jeff Squyres from Cisco Systems presents: How to make MPI Awesome – MPI Sessions.
As a proposal for future versions of the MPI Standard, MPI Sessions could become a powerful tool tool to improve system resiliency as we move towards exascale.
MPI Sessions in a nutshell:
- A “session” is a local handle to the MPI library. You can create lots of sessions in a single MPI process; each creates a self-contained, isolated entry point to the MPI library.
- It may well be possible to have a different MPI thread level on each session.
- From a session, you can create MPI_Groups by querying the underlying run-time system.
- You can create MPI_Comms from these MPI_Groups.
- You not longer have to call MPI_INIT / MPI_FINALIZE (you can create communicators from sessions); these functions now become the constructor / destructor for MPI_COMM_WORLD and MPI_COMM_SELF.