EFA is a network interface for Amazon EC2 instances that enables customers to run applications requiring high levels of inter-node communications at scale on AWS. With EFA, High Performance Computing (HPC) applications using the Message Passing Interface (MPI) and Machine Learning (ML) applications using NVIDIA Collective Communications Library (NCCL) can scale to thousands of CPUs or GPUs.
The Libfabric library is the preferred interface for accessing the EFA hardware. Libfabric is a core component of OpenFabrics Interfaces (OFI) and the library that defines and exports the user-space API of OFI. It is typically the only software that applications deal with directly.