AWS Certified DevOps Engineer – Professional (DOP-C02) — Question 119

A company manages a web application that runs on Amazon EC2 instances behind an Application Load Balancer (ALB). The EC2 instances run in an Auto Scaling group across multiple Availability Zones. The application uses an Amazon RDS for MySQL DB instance to store the data. The company has configured Amazon Route 53 with an alias record that points to the ALB.

A new company guideline requires a geographically isolated disaster recovery (DR) site with an RTO of 4 hours and an RPO of 15 minutes.

Which DR strategy will meet these requirements with the LEAST change to the application stack?

Answer options

• A. Launch a replica environment of everything except Amazon RDS in a different Availability Zone. Create an RDS read replica in the new Availability Zone, and configure the new stack to point to the local RDS DB instance. Add the new stack to the Route 53 record set by using a health check to configure a failover routing policy.
• B. Launch a replica environment of everything except Amazon RDS in a different AWS Region. Create an RDS read replica in the new Region, and configure the new stack to point to the local RDS DB instance. Add the new stack to the Route 53 record set by using a health check to configure a latency routing policy.
• C. Launch a replica environment of everything except Amazon RDS in a different AWS Region. In the event of an outage, copy and restore the latest RDS snapshot from the primary Region to the DR Region. Adjust the Route 53 record set to point to the ALB in the DR Region.
• D. Launch a replica environment of everything except Amazon RDS in a different AWS Region. Create an RDS read replica in the new Region, and configure the new environment to point to the local RDS DB instance. Add the new stack to the Route 53 record set by using a health check to configure a failover routing policy. In the event of an outage, promote the read replica to primary.

Correct answer: D

Explanation

Option D is the correct answer as it establishes a duplicate environment in a different AWS Region while creating an RDS read replica, which allows for quick failover and meets the RTO and RPO requirements with minimal changes. Option A does not provide geographic isolation, while options B and C do not effectively address the failover mechanism with the read replica promotion needed for swift recovery.