AWS DevOps Engineer Professional DOP-C01 – Question084

A healthcare company has a critical application running in AWS. Recently, the company experienced some down time. If it happens again, the company needs to be able to recover its application in another AWS Region. The application uses Elastic Load Balancing and Amazon EC2 instances. The company also maintains a custom AMI that contains its application. This AMI is changed frequently. The workload is required to run in the primary region, unless there is a regional service disruption, in which case traffic should fail over to the new region. Additionally, the cost for the second region needs to be low. The RTO is 2 hours. Which solution allows the company to fail over to another region in the event of a failure, and also meet the above requirements?

A.
Maintain a copy of the AMI from the main region in the backup region. Create an Auto Scaling group with one instance using a launch configuration that contains the copied AMI. Use an Amazon Route 53 record to direct traffic to the load balancer in the backup region in the event of failure, as required. Allow the Auto Scaling group to scale out as needed during a failure.
B. Automate the copying of the AMI in the main region to the backup region. Generate an AWS Lambda function that will create an EC2 instance from the AMI and place it behind a load balancer. Using the same Lambda function, point the Amazon Route 53 record to the load balancer in the backup region. Trigger the Lambda function in the event of a failure.
C. Place the AMI in a replicated Amazon S3 bucket. Generate an AWS Lambda function that can create a launch configuration and assign it to an already created Auto Scaling group. Have one instance in this Auto Scaling group ready to accept traffic. Trigger the Lambda function in the event of a failure. Use an Amazon Route 53 record and modify it with the same Lambda function to point to the load balancer in the backup region.
D. Automate the copying of the AMI to the backup region. Create an AWS Lambda function that can create a launch configuration and assign it to an already created Auto Scaling group. Set the Auto Scaling group maximum size to 0 and only increase it with the Lambda function during a failure. Trigger the Lambda function in the event of a failure. Use an Amazon Route 53 record and modify it with the same Lambda function to point to the load balancer in the backup region.

Correct Answer: D