AWS Certified Solutions Architect – Associate (SAA-C03) — Question 1008

An ecommerce company wants a disaster recovery solution for its Amazon RDS DB instances that run Microsoft SQL Server Enterprise Edition. The company's current recovery point objective (RPO) and recovery time objective (RTO) are 24 hours.

Which solution will meet these requirements MOST cost-effectively?

Answer options

• A. Create a cross-Region read replica and promote the read replica to the primary instance.
• B. Use AWS Database Migration Service (AWS DMS) to create RDS cross-Region replication.
• C. Use cross-Region replication every 24 hours to copy native backups to an Amazon S3 bucket.
• D. Copy automatic snapshots to another Region every 24 hours.

Correct answer: D

Explanation

Copying automated RDS snapshots to another AWS Region every 24 hours is the most cost-effective solution because it leverages built-in RDS capabilities and only incurs minimal storage costs, easily satisfying the 24-hour RPO/RTO. In contrast, options like cross-Region read replicas (Option A) or AWS DMS (Option B) require running continuously active compute resources, which significantly increases costs. Option C is more complex to manage compared to native RDS snapshot copying.