SAA-C03 Question 23
Select 2A company is designing a multi-region disaster recovery solution for its web application. The application is hosted on Amazon EC2 instances behind an Application Load Balancer (ALB). The database is hosted on Amazon RDS. The company wants to ensure high availability and minimize downtime in case of a regional failure. Which combination of strategies should the company use?
- A
Deploy the application in multiple AWS Regions and use Amazon Route 53 to configure DNS failover.
- B
Enable Multi-AZ for the Amazon RDS instance to ensure automatic failover within the same region.
- C
Set up a read replica in another AWS Region for the Amazon RDS instance, and promote it to a standalone database in case of failure.
- D
Use an Auto Scaling group to launch replacement EC2 instances in the same Availability Zone during a failure.
- E
Deploy the ALB in a single Availability Zone to reduce costs.
Show answer and explanation
Correct answers: A, C
Explanation
To design a multi-region disaster recovery solution, the application and database must be replicated across multiple AWS Regions. Route 53 can facilitate automated DNS failover, and a read replica in another region ensures database availability during a regional outage. Multi-AZ RDS and single AZ ALB deployments do not cover regional failures, and Auto Scaling in one AZ only addresses instance-level failures.
- A. Correct.
This is correct. Deploying the application in multiple AWS Regions ensures redundancy, and Amazon Route 53 can be used to route traffic to the healthy region during a regional failure.
- B. Incorrect.
This is incorrect. Multi-AZ deployments only provide failover within the same region, which does not protect against a regional failure.
- C. Correct.
This is correct. Setting up a read replica in another region allows you to promote it to a standalone database in case the primary region becomes unavailable.
- D. Incorrect.
This is incorrect. Using an Auto Scaling group in the same Availability Zone does not provide protection against regional or Availability Zone failures.
- E. Incorrect.
This is incorrect. Deploying the ALB in a single Availability Zone creates a single point of failure and goes against high availability best practices.