SOA-C02 Question 119
Select 2Your organization hosts a critical web application on AWS. The application runs on Amazon EC2 instances behind an Application Load Balancer, with data stored in an Amazon RDS database. To ensure minimal downtime in the event of a disaster, you have implemented a cross-region disaster recovery (DR) strategy. Recently, the primary region experienced an outage, and you need to failover to the DR region. Which of the following actions should you take to restore the application in the DR region?
- A
Update the DNS records in Route 53 to point to the Application Load Balancer in the DR region.
- B
Promote the read replica in the DR region to a standalone RDS instance.
- C
Manually start the EC2 instances in the DR region.
- D
Ensure the DR region’s EC2 instances are part of an Auto Scaling group for automatic recovery.
- E
Enable Multi-AZ for your RDS instance to avoid the need for manual promotion in the DR region.
Show answer and explanation
Correct answers: A, B
Explanation
To perform disaster recovery in a cross-region failover scenario, you need to redirect traffic to the DR region by updating DNS records (Route 53) and promote the database read replica in the DR region to become the new primary database. Other options, like manually starting EC2 instances or relying solely on Auto Scaling groups, may assist in recovery but do not directly address the failover process. Multi-AZ configurations are specific to high availability within a single region and do not address cross-region disaster recovery.
- A. Correct.
Correct. Updating the DNS records in Route 53 is necessary to redirect traffic to the Application Load Balancer in the DR region after a failover.
- B. Correct.
Correct. Promoting the read replica in the DR region is required to make it the primary database for the application in the DR region.
- C. Incorrect.
Incorrect. While EC2 instances may need to be manually started in certain configurations, using Auto Scaling groups in the DR region is the recommended approach for automatic recovery.
- D. Incorrect.
Incorrect. While Auto Scaling groups are beneficial for automatic recovery, this action alone does not directly restore the application in the DR region during a failover.
- E. Incorrect.
Incorrect. Multi-AZ applies to instances within the same region and does not provide protection against regional outages. You need to manually promote the read replica in the DR region.