A network engineer needs to design the architecture for a high performance computing (HPC) workload. Amazon EC2 instances will require 10 Gbps flows and an aggregate throughput of up to 100 Gbps across many instances with low-latency communication. Which architecture solution will optimize this workload?

The requirements for high-throughput (100 Gbps aggregate), low-latency, tightly-coupled communication are characteristic of High Performance Computing (HPC) workloads. The optimal AWS architecture for this involves using a Cluster Placement Group, which places instances in a single Availability Zone to minimize network latency. Additionally, Elastic Fabric Adapter (EFA) is a specialized network interface designed for HPC that bypasses the kernel to provide lower, more consistent latency and higher throughput than standard Elastic Network Adapters (ENAs). Placing all nodes in a single subnet within the cluster placement group is a best practice for EFA performance.

B. A spread placement group is designed for high availability by separating instances, which increases latency and is unsuitable for HPC.
C. Using multiple VPCs and AWS Transit Gateway introduces significant network latency, which is detrimental to tightly-coupled HPC workloads.
D. A cluster placement group cannot span multiple Availability Zones; its purpose is to co-locate instances within a single AZ for low latency.

1. Amazon EC2 User Guide for Linux Instances. (2023). Placement groups. Amazon Web Services. Retrieved from https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html (Section "Cluster placement groups" states they are for applications that need low network latency and are within a single Availability Zone).

2. Amazon EC2 User Guide for Linux Instances. (2023). Elastic Fabric Adapter. Amazon Web Services. Retrieved from https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/efa.html (Describes EFA as a network device for accelerating HPC applications and its benefits of lower latency and higher throughput).

3. Amazon EC2 User Guide for Linux Instances. (2023). EFA and cluster placement groups. Amazon Web Services. Retrieved from https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/efa.html#efa-cluster-pgs (States "We recommend that you launch the instances that you intend to use with EFA into a cluster placement group.").