AWS Certified Solutions Architect – Associate (SAA-C02) — Question 583

A company's application is having performance issues. The application is stateful and needs to complete in-memory tasks on Amazon EC2 instances. The company used AWS CloudFormation to deploy infrastructure and used the M5 EC2 instance family. As traffic increased, the application performance degraded.
Users are reporting delays when the users attempt to access the application.
Which solution will resolve these issues in the MOST operationally efficient way?

Answer options

• A. Replace the EC2 instances with T3 EC2 instances that run in an Auto Scaling group. Make the changes by using the AWS Management Console.
• B. Modify the CloudFormation templates to run the EC2 instances in an Auto Scaling group. Increase the desired capacity and the maximum capacity of the Auto Scaling group manually when an increase is necessary.
• C. Modify the CloudFormation templates. Replace the EC2 instances with R5 EC2 instances. Use Amazon CloudWatch built-in EC2 memory metrics to track the application performance for future capacity planning.
• D. Modify the CloudFormation templates. Replace the EC2 instances with R5 EC2 instances. Deploy the Amazon CloudWatch agent on the EC2 instances to generate custom application latency metrics for future capacity planning.

Correct answer: D

Explanation

R5 instances are memory-optimized, which directly addresses the performance issues of an application performing heavy in-memory tasks. Since the infrastructure was deployed with AWS CloudFormation, modifying the templates maintains operational consistency and infrastructure-as-code best practices. Additionally, standard Amazon CloudWatch metrics do not collect memory utilization or custom application latency, meaning the CloudWatch agent must be deployed to gather these custom metrics for future capacity planning.