Elastic Fabric Adapter (EFA)

 

• An Elastic Fabric Adapter (EFA) is a network device that you can attach to your Amazon EC2 instance to accelerate High Performance Computing (HPC) and machine learning applications.
• An EFA is an Elastic Network Adapter (ENA) with an additional OS-bypass functionality. 
• How It Works

• EFA integrates with 
  • Libfabric 1.9.0 and it supports Open MPI 4.0.2 and Intel MPI 2019 Update 6 for HPC applications, and 
  • Nvidia Collective Communications Library (NCCL) for machine learning applications.

• With an EFA, HPC applications use Intel Message Passing Interface (MPI) or Nvidia Collective Communications Library (NCCL) to interface with the Libfabric API. The Libfabric API bypasses the operating system kernel and communicates directly with the EFA device to place packets on the network.
• Supported AMIs
  • Amazon Linux
  • Amazon Linux 2
  • RHEL 7.6 and RHEL 7.7
  • CentOS 7
  • Ubuntu 16.04 and Ubuntu 18.04

• Examples of HPC Applications
  • computational fluid dynamics (CFD)
  • crash simulations
  • weather simulations

Limitations

• • You can attach only one EFA per instance.
  • EFA OS-bypass traffic is limited to a single subnet. EFA traffic cannot be sent from one subnet to another. Normal IP traffic from the EFA can be sent from one subnet to another.
  • EFA OS-bypass traffic is not routable. Normal IP traffic from the EFA remains routable.
  • The EFA must be a member of a security group that allows all inbound and outbound traffic to and from the security group itself.

Pricing

EFA is available as an optional EC2 networking feature that you can enable on any supported EC2 instance at no additional cost.