AWS Certified Solutions Architect – Professional (SAP-C02) — Question 154

A company is running a critical stateful web application on two Linux Amazon EC2 instances behind an Application Load Balancer (ALB) with an Amazon RDS for MySQL database. The company hosts the DNS records for the application in Amazon Route 53. A solutions architect must recommend a solution to improve the resiliency of the application.

The solution must meet the following objectives:

• Application tier: RPO of 2 minutes. RTO of 30 minutes
• Database tier: RPO of 5 minutes. RTO of 30 minutes

The company does not want to make significant changes to the existing application architecture. The company must ensure optimal latency after a failover.

Which solution will meet these requirements?

Answer options

• A. Configure the EC2 instances to use AWS Elastic Disaster Recovery. Create a cross-Region read replica for the RDS DB instance. Create an ALB in a second AWS Region. Create an AWS Global Accelerator endpoint, and associate the endpoint with the ALBs. Update DNS records to point to the Global Accelerator endpoint.
• B. Configure the EC2 instances to use Amazon Data Lifecycle Manager (Amazon DLM) to take snapshots of the EBS volumes. Configure RDS automated backups. Configure backup replication to a second AWS Region. Create an ALB in the second Region. Create an AWS Global Accelerator endpoint, and associate the endpoint with the ALBs. Update DNS records to point to the Global Accelerator endpoint.
• C. Create a backup plan in AWS Backup for the EC2 instances and RDS DB instance. Configure backup replication to a second AWS Region. Create an ALB in the second Region. Configure an Amazon CloudFront distribution in front of the ALB. Update DNS records to point to CloudFront.
• D. Configure the EC2 instances to use Amazon Data Lifecycle Manager (Amazon DLM) to take snapshots of the EBS volumes. Create a cross-Region read replica for the RDS DB instance. Create an ALB in a second AWS Region. Create an AWS Global Accelerator endpoint, and associate the endpoint with the ALBs.

Correct answer: A

Explanation

Option A is correct because it utilizes AWS Elastic Disaster Recovery and a cross-Region read replica for the RDS database, fulfilling the RPO and RTO requirements while allowing for minimal changes to the architecture. Options B and D, while similar, do not include the use of Elastic Disaster Recovery, which is crucial for meeting the specified objectives. Option C suggests using AWS Backup and CloudFront, which does not meet the RPO and RTO requirements for the application and database tiers.