AWS Certified Solutions Architect – Associate (SAA-C02) — Question 593

A company is running a web application on Amazon EC2 instances in an Auto Scaling group. The application uses a database that runs on an Amazon RDS for
PostgreSQL DB instance. The application performs slowly as traffic increases, and the database experiences a heavy read load during periods of high traffic.
Which actions should a solutions architect take to resolve these performance issues? (Choose two.)

Answer options

• A. Enable auto scaling for the DB instance.
• B. Create a read replica for the DB instance. Configure the application to send read traffic to the read replica.
• C. Enable Multi-AZ for the DB instance. Configure the application to send read traffic to the standby DB instance.
• D. Create an Amazon ElastiCache cluster. Configure the application to cache query results in the ElastiCache cluster.
• E. Configure the Auto Scaling group subnets to ensure that the EC2 instances are provisioned in the same Availability Zone as the DB instance.

Correct answer: B, D

Explanation

Creating an Amazon RDS read replica (B) allows the application to offload read traffic from the primary database instance, directly addressing the heavy read load. Implementing an Amazon ElastiCache cluster (D) caches frequent database queries in-memory, which significantly reduces the query volume hitting the database. Other options like Multi-AZ (C) do not allow reads on the standby instance, while RDS storage auto scaling (A) and restricting EC2 instances to a single Availability Zone (E) do not resolve read performance bottlenecks.