Question 1

Domain 2: Design for New Solutions

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 (OR) solution with an RPO of 5 minutes. Which solution will meet the company's requirements?

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. Create AMts 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. C. Maintain another running copy of the web and application server stack in the DR Region using AWS CloudFormation drill detection. Configure cross-Region snapshots ol 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. D. 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.

Correct answer: D

Explanation

An RPO of 5 minutes requires near-continuous data replication, which a cross-Region read replica for Amazon RDS MySQL provides. This also matches disaster recovery guidance for “configuring data and database replication” and using “multi-Region architectures”; promoting the replica and reprovisioning servers from AMIs restores the three-tier stack quickly.

Why each option is right or wrong

AWS Backup cross-Region backups every 5 minutes are backup-and-restore, not continuous database replication.

B. Create AMts 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.

AWS Glue is for ETL, not synchronizing RDS MySQL to another database instance.

C. Maintain another running copy of the web and application server stack in the DR Region using AWS CloudFormation drill detection. Configure cross-Region snapshots ol 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.

CloudFormation does not provide 'drill detection'; restoring from 5-minute snapshots is slower than replication.

D. 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.

An RPO of 5 minutes requires database replication with very low data loss, and Amazon RDS MySQL cross-Region read replicas asynchronously replicate changes to a secondary Region so the standby is only minutes behind the primary. Under the Amazon RDS documentation, a read replica can be promoted to a standalone DB instance during recovery, and the application tier can then be rebuilt from pre-copied AMIs via CloudFormation, which is consistent with a multi-Region DR design that preserves the database state within the stated 5-minute window.