Which MPI distribution is no longer supported on Oracle Cloud Infrastructure (OCI)?

OCI MPI is the correct answer because it has been officially deprecated by Oracle, meaning it is no longer maintained or supported on the Oracle Cloud Infrastructure. This lack of ongoing support implies that any issues or bugs that arise will not be addressed, which can lead to potential problems for users relying on this distribution for high-performance computing tasks.

In contrast, the other options—OpenMPI, MPICH, and MVAPICH—continue to receive updates and support, making them viable choices for users who require a reliable and actively maintained MPI implementation. These alternatives are widely used in the community, and users have access to current features, bug fixes, and community support. Therefore, OCI MPI's lack of support distinguishes it from other available MPI distributions in the context of Oracle Cloud Infrastructure.