The Open Fabrics Interfaces (OFI) is a framework focused on exporting fabric communication services to applications.

Libfabric is a software library instantiation of OFI with the following objectives:

Libfabric is being developed by the OFI Working Group (OFIWG or "ofee-wig"), a subgroup of the OpenFabrics Alliance. However, participation in the OFIWG is open to anyone. The charter of the OFIWG is:

Develop an extensible, open source framework and interfaces aligned with upper-layer protocols and application needs for high-performance fabric services.

The goal of OFI and libfabric is to define interfaces that enable a tight semantic map between applications and underlying fabric services. Specifically, libfabric software interfaces have been co-designed with fabric hardware providers and application developers, with a focus on the needs of HPC users. OFI supports multiple interface semantics, is fabric and vendor agnostic, and leverages and expands the existing RDMA open source community. A high-level view of the libfabric architecture is shown below.

Libfabric is designed to minimize the impedance mismatch between applications, including middleware such as MPI, SHMEM, and PGAS, and fabric communication hardware. Its interfaces target high-bandwidth, low-latency NICs, with a goal to scale to tens of thousands of nodes.

First: read the documentation.

The bulk of the libfabric code base is being developed in this GitHub repository. As part of this repository, a set of Linux man pages are being carefully written to exactly specify the libfabric APIs. Read through these man pages to get a sense of the libfabric APIs.

Second: become part of the conversation.

Join the ofiwg mailing list. Notices of the Tuesday-weekly OFIWG Webexes are sent on this list; anyone can join the calls to listen and participate in the design of libfabric.