AWS Certified Solutions Architect – Professional — Question 403

A company has a three-tier application running on AWS with a web server, an application server, and an Amazon RDS MySQL DB instance. A solutions architect is designing a disaster recovery (DR) solution with an RPO of 5 minutes.
Which solution will meet the company's requirements?

Answer options

• A. Configure AWS Backup to perform cross-Region backups of all servers every 5 minutes. Reprovision the three tiers in the DR Region from the backups using AWS CloudFormation in the event of a disaster.
• B. Maintain another running copy of the web and application server stack in the DR Region using AWS CloudFormation drift detection. Configure cross-Region snapshots of the DB instance to the DR Region every 5 minutes. In the event of a disaster, restore the DB instance using the snapshot in the DR Region.
• C. Use Amazon EC2 Image Builder to create and copy AMIs of the web and application server to both the primary and DR Regions. Create a cross-Region read replica of the DB instance in the DR Region. In the event of a disaster, promote the read replica to become the master and reprovision the servers with AWS CloudFormation using the AMIs.
• D. Create AMIs of the web and application servers in the DR Region. Use scheduled AWS Glue jobs to synchronize the DB instance with another DB instance in the DR Region. In the event of a disaster, switch to the DB instance in the DR Region and reprovision the servers with AWS CloudFormation using the AMIs.

Correct answer: C

Explanation

Creating a cross-Region read replica of the Amazon RDS MySQL DB instance provides asynchronous replication that easily supports a low RPO of 5 minutes, and promoting the replica during a disaster is a fast recovery mechanism. Using Amazon EC2 Image Builder to distribute AMIs to the DR Region allows AWS CloudFormation to quickly reprovision the stateless web and application servers. Other options are incorrect because copying snapshots every 5 minutes is not supported, AWS Backup cannot run every 5 minutes, and AWS Glue is an ETL service not designed for real-time transactional database replication.