AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 222

You are architecting an HPC solution in AWS. The system consists of a cluster of EC2 instances that require low-latency communications between them.
Which method should you use to set up a cluster to meet these requirements?

Answer options

• A. Create a VPC with one subnet in a single Availability Zone. Keep the size of the subnet equal to the number of instances required in the cluster. Launch instances for the cluster in this small subnet to guarantee low-latency network performance.
• B. Create a placement group. Choose an EC2 instance type compatible with placement groups for the cluster. Launch instances for the cluster in the placement group.
• C. Launch Amazon EC2 instances with the largest available number of cores and RAM. Attach all instances to an Amazon EBS PIOPS volume. Implement a shared memory system across all instances in the cluster, using this shared EBS volume to minimize latency of communication.
• D. Choose an EC2 instance type that offers enhanced networking. Attach a 10-Gbps non-blocking elastic network interface to the instances. Configure the elastic network interface to optimize network performance to reduce latency.

Correct answer: B

Explanation

The correct answer is B, as creating a placement group allows for instances to be physically located close together, which is essential for low-latency communication. Option A fails to address the need for proximity of instances, while option C suggests a shared EBS volume, which does not provide the required low-latency communication. Option D focuses on enhanced networking but does not guarantee the physical closeness necessary for minimal latency.