DOP-C02 Question 198
Select 3Your company hosts a mission-critical application on AWS using an active-passive disaster recovery strategy. The primary region is us-east-1, and the secondary region is us-west-2. The application uses Amazon RDS for its database and Amazon EC2 instances for the compute layer. To minimize downtime during a disaster recovery (DR) event, which actions should you take to prepare the secondary region to become fully operational?
- A
Enable cross-region read replicas for the Amazon RDS instance and regularly promote the replica in the secondary region to test failover.
- B
Deploy EC2 instances in the secondary region with the same configuration as the primary region and keep them stopped until needed.
- C
Set up Route 53 health checks for the primary region and configure DNS failover to the secondary region.
- D
Use AWS Backup to create daily backups of the RDS database in the primary region and restore them in the secondary region during a DR event.
- E
Maintain a pre-warmed load balancer in the secondary region to handle traffic immediately upon failover.
Show answer and explanation
Correct answers: B, C, E
Explanation
An active-passive disaster recovery strategy requires the secondary region to be partially prepared to minimize downtime during a failover. EC2 instances should be pre-deployed but stopped to save costs, and Route 53 health checks and DNS failover should be in place to redirect traffic automatically. A pre-warmed load balancer in the secondary region ensures that application traffic can be served immediately post-failover. Promoting cross-region replicas frequently or relying solely on backup and restore processes are not optimal practices for this scenario.
- A. Incorrect.
Cross-region read replicas are useful for minimizing RTO, but regularly promoting them to test failover is not a best practice as it can disrupt ongoing replication and introduce inconsistencies.
- B. Correct.
Deploying EC2 instances in the secondary region with the same configuration ensures that the compute layer is ready for failover. Keeping them stopped minimizes cost until they are required.
- C. Correct.
Route 53 health checks and DNS failover are necessary to redirect traffic to the secondary region during a DR event.
- D. Incorrect.
Using AWS Backup for daily backups is a backup strategy but is not ideal for minimizing downtime in an active-passive DR setup, as restoring backups can take significant time.
- E. Correct.
A pre-warmed load balancer in the secondary region ensures that the application can handle traffic immediately after failover, reducing latency and downtime.