AWS Certified Solutions Architect – Associate (SAA-C03) — Question 317

A company wants to run an in-memory database for a latency-sensitive application that runs on Amazon EC2 instances. The application processes more than 100,000 transactions each minute and requires high network throughput. A solutions architect needs to provide a cost-effective network design that minimizes data transfer charges.

Which solution meets these requirements?

Answer options

• A. Launch all EC2 instances in the same Availability Zone within the same AWS Region. Specify a placement group with cluster strategy when launching EC2 instances.
• B. Launch all EC2 instances in different Availability Zones within the same AWS Region. Specify a placement group with partition strategy when launching EC2 instances.
• C. Deploy an Auto Scaling group to launch EC2 instances in different Availability Zones based on a network utilization target.
• D. Deploy an Auto Scaling group with a step scaling policy to launch EC2 instances in different Availability Zones.

Correct answer: A

Explanation

A cluster placement group places EC2 instances within a single Availability Zone, providing the lowest possible network latency and highest throughput while eliminating cross-AZ data transfer costs. Options B, C, and D all involve deploying instances across multiple Availability Zones, which introduces latency and incurs cross-AZ data transfer fees, failing to meet the cost-effectiveness and low-latency requirements.