Question #1453
A company operates a web application on AWS using Amazon EC2 instances behind an Application Load Balancer within an Auto Scaling group. The application stores data in an Amazon DynamoDB table. To ensure business continuity, the company needs to implement a disaster recovery plan that allows rapid failover to another AWS Region with minimal downtime.
Which approach should a solutions architect recommend to meet these requirements with the LEAST downtime?
Set up an Auto Scaling group and Application Load Balancer in the secondary Region. Replicate the DynamoDB table using global tables. Use Amazon Route 53 with health checks to route traffic to the secondary Region's load balancer during failover.
Use AWS CloudFormation to define infrastructure templates for EC2, ALB, and DynamoDB in the secondary Region. Configure Route 53 failover to direct traffic to the secondary Region upon manual intervention.
Deploy an Auto Scaling group and ALB in the secondary Region. Configure DynamoDB cross-region backups with scheduled restore processes. Implement a CloudWatch alarm to trigger a Lambda function that updates Route 53 to the secondary Region.
Create a standby environment in the secondary Region using EC2 instances and ALB. Use DynamoDB on-demand backups for data recovery. Set up Route 53 with weighted routing to gradually shift traffic to the secondary Region.
Explanation
The correct answer is A because:
- DynamoDB Global Tables enable automatic, real-time replication of data across regions, ensuring the secondary Region has up-to-date data for rapid failover.
- Auto Scaling and ALB in the secondary Region maintain a scalable and available infrastructure ready to handle traffic.
- Route 53 with health checks automates DNS failover to the secondary Region when the primary Region becomes unhealthy, minimizing downtime.
Other options are incorrect because:
- B relies on manual intervention, which delays failover.
- C uses cross-region backups (not real-time) and scheduled restores, leading to potential data loss and slower recovery.
- D depends on on-demand backups (not real-time) and weighted routing (gradual traffic shift), which do not meet rapid failover requirements.
Key Points: Use DynamoDB Global Tables for real-time replication and Route 53 health checks for automated, rapid failover in disaster recovery scenarios.
Answer
The correct answer is: A