AWS Certified DevOps Engineer – Professional (DOP-C02) — Question 361

A DevOps team operates an integration service that runs on an Amazon EC2 instance. The DevOps team uses Amazon Route 53 to manage the integration service's domain name by using a simple routing record. The integration service is stateful and uses Amazon Elastic File System (Amazon EFS) for data storage and state storage. The integration service does not support load balancing between multiple nodes.

The DevOps team deploys the integration service on a new EC2 instance as a warm standby to reduce the mean time to recovery. The DevOps team wants the integration service to automatically fail over to the standby EC2 instance.

Which solution will meet these requirements?

Answer options

• A. Update the existing Route 53 DNS record's routing policy to weighted. Set the existing DNS record's weighting to 100. For the same domain, add a new DNS record that points to the standby EC2 instance. Set the new DNS record's weighting to 0. Associate an application health check with each record.
• B. Update the existing Route 53 DNS record's routing policy to weighted. Set the existing DNS record's weighting to 99. For the same domain, add a new DNS record that points to the standby EC2 instance. Set the new DNS record's weighting to 1. Associate an application health check with each record.
• C. Create an Application Load Balancer (ALB). Update the existing Route 53 record to point to the ALB. Create a target group for each EC2 instance. Configure an application health check on each target group. Associate both target groups with the same ALB listener. Set the primary target group's weighting to 100. Set the standby target group's weighting to 0.
• D. Create an Application Load Balancer (ALB). Update the existing Route 53 record to point to the ALB. Create a target group for each EC2 instance. Configure an application health check on each target group. Associate both target groups with the same ALB listener. Set the primary target group's weighting to 99. Set the standby target group's weighting to 1.

Correct answer: A

Explanation

Route 53 weighted routing can be configured for active-passive failover by setting the primary record's weight to 100 and the standby record's weight to 0. When health checks are associated, Route 53 will only route traffic to the standby instance if the primary instance fails its health check. Since the integration service explicitly does not support load balancing, introducing an Application Load Balancer is incorrect and adds unnecessary complexity.