AWS Certified Solutions Architect – Associate (SAA-C02) — Question 360

A company has a multi-tier application deployed on several Amazon EC2 instances in an Auto Scaling group. An Amazon RDS for Oracle instance is the application's data layer that uses Oracle-specific PL/SQL functions. Traffic to the application has been steadily increasing. This is causing the EC2 instances to become overloaded and the RDS instance to run out of storage. The Auto Scaling group does not have any scaling metrics and defines the minimum healthy instance count only. The company predicts that traffic will continue to increase at a steady but unpredictable rate before leveling off.
What should a solutions architect do to ensure the system can automatically scale for the increased traffic? (Choose two.)

Answer options

• A. Configure storage Auto Scaling on the RDS for Oracle instance.
• B. Migrate the database to Amazon Aurora to use Auto Scaling storage.
• C. Configure an alarm on the RDS for Oracle instance for low free storage space.
• D. Configure the Auto Scaling group to use the average CPU as the scaling metric.
• E. Configure the Auto Scaling group to use the average free memory as the scaling metric.

Correct answer: A, D

Explanation

Enabling storage Auto Scaling on the RDS for Oracle instance allows the database to automatically scale storage with zero downtime as data grows. Configuring the EC2 Auto Scaling group to use average CPU utilization provides a reliable, built-in metric to scale the compute tier dynamically based on traffic load. Migrating to Amazon Aurora is not viable due to the application's dependency on Oracle-specific PL/SQL, and free memory is not a default CloudWatch metric for EC2 scaling.