Q97 — AWS SAA-C03 Ch.12

Question 97 of 100 | ← Chapter 12

Q897. A company hosts its application in the AWS Cloud. The application runs on Amazon EC2 instances in an Auto Scaling group behind an Elastic Load Balancing (ELB) load balancer. The application connects to an Amazon DynamoDB table.For disaster recovery (DR) purposes, the company wants to ensure that the application is available from another AWS Region with minimal downtime.Which solution will meet these requirements with the LEAST downtime?

Correct Answer: A. Create an Auto Scaling group and an ELB in the DR Region. Configure the DynamoDB table as a global table. Configure DNS failover to point to the new DR Region's ELB.

Explanation

To meet the requirement of ensuring minimal downtime for the application in a disaster recovery (DR) scenario, the following solution can be recommended:A. Create an Auto Scaling group and an ELB in the DR Region. Configure the DynamoDB table as a global table. Configure DNS failover to point to the new DR Region's ELB.By creating an Auto Scaling group and an ELB in the DR Region, you can ensure that the application can be launched and scaled in the event of a disaster. The Auto Scaling group will automatically provision and terminate EC2 instances based on the demand and health of the instances.Configuring the DynamoDB table as a global table enables automatic replication of the table data to multiple AWS Regions. This ensures that the data is available in the DR Region, allowing the application to seamlessly switch to the DR Region in case of a disaster.By configuring DNS failover, you can direct traffic to the new DR Region's ELB in the event of a failure in the primary Region. DNS failover allows you to route traffic to the DR Region with minimal downtime, providing a smooth transition for your users.Option B suggests creating an AWS CloudFormation template to create EC2 instances, ELBs, and DynamoDB tables to be launched when necessary. While this approach provides automation for launching resources, it does not offer the same level of seamless failover and replication as the global table feature in DynamoDB. Therefore, Option B is not the most suitable solution.Option C suggests creating an AWS CloudFormation template to create EC2 instances and an ELB to be launched when necessary. It also recommends configuring the DynamoDB table as a global table. However, it does not mention DNS failover, which is essential for directing traffic to the DR Region. Therefore, Option C is not the most appropriate solution.Option D suggests creating an Auto Scaling group and an ELB in the DR Region, configuring the DynamoDB table as a global table, and using an Amazon CloudWatch alarm with an AWS Lambda function to update Amazon Route 53. While this solution incorporates DNS routing, it involves a manual trigger with a CloudWatch alarm and Lambda function invocation, which may introduce additional delays and potential points of failure. Therefore, Option D is not the most optimal solution.In summary, to ensure minimal downtime for the application in a disaster recovery scenario, creating an Auto Scaling group and an ELB in the DR Region, configuring the DynamoDB table as a global table, and configuring DNS failover to point to the new DR Region's ELB (Option A) is the most suitable solution.