AWS Certified Solutions Architect – Associate (SAA-C03) — Question 654

A company has a web application that includes an embedded NoSQL database. The application runs on Amazon EC2 instances behind an Application Load Balancer (ALB). The instances run in an Amazon EC2 Auto Scaling group in a single Availability Zone.

A recent increase in traffic requires the application to be highly available and for the database to be eventually consistent.

Which solution will meet these requirements with the LEAST operational overhead?

Answer options

• A. Replace the ALB with a Network Load Balancer. Maintain the embedded NoSQL database with its replication service on the EC2 instances.
• B. Replace the ALB with a Network Load Balancer. Migrate the embedded NoSQL database to Amazon DynamoDB by using AWS Database Migration Service (AWS DMS).
• C. Modify the Auto Scaling group to use EC2 instances across three Availability Zones. Maintain the embedded NoSQL database with its replication service on the EC2 instances.
• D. Modify the Auto Scaling group to use EC2 instances across three Availability Zones. Migrate the embedded NoSQL database to Amazon DynamoDB by using AWS Database Migration Service (AWS DMS).

Correct answer: D

Explanation

Spreading the EC2 instances across three Availability Zones ensures high availability for the application tier. Migrating the embedded NoSQL database to Amazon DynamoDB offloads replication and maintenance tasks to a fully managed AWS service that natively supports eventual consistency, thereby minimizing operational overhead compared to managing database replication manually on EC2 instances.