AWS Certified Solutions Architect – Professional — Question 490

A company has an application that sells tickets online and experiences bursts of demand every 7 days. The application has a stateless presentation layer running on Amazon EC2, an Oracle database to store unstructured data catalog information, and a backend API layer. The front-end layer uses an Elastic Load Balancer to distribute the load across nine On-Demand instances over three Availability Zones (AZs). The Oracle database is running on a single EC2 instance. The company is experiencing performance issues when running more than two concurrent campaigns. A solutions architect must design a solution that meets the following requirements:
✑ Address scalability issues.
✑ Increase the level of concurrency.
✑ Eliminate licensing costs.
✑ Improve reliability.
Which set of steps should the solutions architect take?

Answer options

• A. Create an Auto Scaling group for the front end with a combination of On-Demand and Spot Instances to reduce costs. Convert the Oracle database into a single Amazon RDS reserved DB instance.
• B. Create an Auto Scaling group for the front end with a combination of On-Demand and Spot Instances to reduce costs. Create two additional copies of the database instance, then distribute the databases in separate AZs.
• C. Create an Auto Scaling group for the front end with a combination of On-Demand and Spot Instances to reduce costs. Convert the tables in the Oracle database into Amazon DynamoDB tables.
• D. Convert the On-Demand Instances into Spot instances to reduce costs for the front end. Convert the tables in the Oracle database into Amazon DynamoDB tables.

Correct answer: A

Explanation

Implementing an Auto Scaling group with a combination of On-Demand and Spot Instances for the stateless presentation layer allows the application to dynamically scale during weekly traffic bursts while keeping costs low. Migrating the Oracle database to a managed Amazon RDS reserved DB instance improves reliability and management efficiency. This combination addresses the scalability and concurrency bottlenecks while optimizing resource costs and operational overhead.