Which solution will meet these business requirements at the LOWEST cost?
Deploy an Amazon Aurora DB cluster and take snapshots of the cluster every 5 minutes. Once a snapshot is complete, copy the snapshot to a secondary Region to serve as a backup in the event of a failure.
Deploy an Amazon RDS instance with a cross-Region read replica in a secondary Region. In the event of a failure, promote the read replica to become the primary.
Deploy an Amazon Aurora DB cluster in the primary Region and another in a secondary Region. Use AWS DMS to keep the secondary Region in sync.
Deploy an Amazon RDS instance with a read replica in the same Region. In the event of a failure, promote the read replica to become the primary.
Explanations:
While Amazon Aurora snapshots can be taken every 5 minutes, snapshots alone do not provide the low RPO and RTO needed for failover. Copying snapshots to a secondary Region does not ensure immediate availability or data consistency in case of a failure, thus failing to meet the business requirements.
Deploying an Amazon RDS instance with a cross-Region read replica allows for low RPO (less than 5 minutes) and RTO (less than 10 minutes). In the event of a failure, the read replica can be promoted to primary, ensuring quick recovery and minimal downtime, making it a cost-effective solution for the requirements.
Deploying two Amazon Aurora DB clusters in different Regions with AWS DMS introduces additional complexity and cost. While it allows for continuous data replication, the setup may be more expensive compared to the RDS cross-Region read replica solution. Furthermore, it may not guarantee the required RPO and RTO effectively.
An RDS instance with a read replica in the same Region may improve availability but does not provide the necessary cross-Region failover capability. In case of a Region failure, the read replica would not be available, failing to meet the requirement of low RPO and RTO in a secondary Region.
If I’m not mistaken, the answer is:
Deploy an Amazon RDS instance with a cross-Region read replica in a secondary Region. In the event of a failure, promote the read replica to become the primary.