AWS Certified Solutions Architect – Associate (SAA-C03) — Question 300

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 scale its storage capacity automatically as space runs low, preventing out-of-storage issues without downtime. Configuring the Auto Scaling group to use average CPU utilization as a scaling metric allows the EC2 instances to scale out dynamically to handle the unpredictable traffic load. Migrating to Amazon Aurora is incorrect because the application relies on Oracle-specific PL/SQL functions, and memory-based scaling is not a standard EC2 Auto Scaling metric without custom CloudWatch agent configurations.