AWS Certified Solutions Architect – Associate (SAA-C03) — Question 341

A company hosts a three-tier web application on Amazon EC2 instances in a single Availability Zone. The web application uses a self-managed MySQL database that is hosted on an EC2 instance to store data in an Amazon Elastic Block Store (Amazon EBS) volume. The MySQL database currently uses a 1 TB Provisioned IOPS SSD (io2) EBS volume. The company expects traffic of 1,000 IOPS for both reads and writes at peak traffic.

The company wants to minimize any disruptions, stabilize performance, and reduce costs while retaining the capacity for double the IOPS. The company wants to move the database tier to a fully managed solution that is highly available and fault tolerant.

Which solution will meet these requirements MOST cost-effectively?

Answer options

• A. Use a Multi-AZ deployment of an Amazon RDS for MySQL DB instance with an io2 Block Express EBS volume.
• B. Use a Multi-AZ deployment of an Amazon RDS for MySQL DB instance with a General Purpose SSD (gp2) EBS volume.
• C. Use Amazon S3 Intelligent-Tiering access tiers.
• D. Use two large EC2 instances to host the database in active-passive mode.

Correct answer: B

Explanation

Amazon RDS with a Multi-AZ deployment provides the required fully managed, highly available, and fault-tolerant database tier. A 1 TB General Purpose SSD (gp2) volume delivers a baseline performance of 3,000 IOPS (3 IOPS per GB), which easily satisfies the requirement for 2,000 IOPS (double the peak of 1,000 IOPS) at a much lower cost than Provisioned IOPS (io2). Other choices either fail to offer a fully managed database service or are unnecessarily expensive.