SOA-C02 Question 51
Select 3Your company hosts a critical e-commerce application on Amazon EC2 instances behind an Application Load Balancer (ALB). To ensure high availability and disaster recovery, the architecture spans two AWS Regions: us-east-1 (primary) and us-west-2 (secondary). The database tier uses Amazon RDS with a Multi-AZ deployment in each Region. Recently, a simulated Regional failure in us-east-1 revealed that the failover process to us-west-2 took longer than expected. What steps can you take to optimize failover time while ensuring minimal downtime?
- A
Use Amazon Route 53 with health checks to implement a failover routing policy between the Regions.
- B
Enable Amazon RDS Read Replicas in us-west-2 and promote it to a standalone database during failover.
- C
Configure the ALB in us-east-1 to redirect traffic to us-west-2 in case of a failure.
- D
Pre-warm the Application Load Balancer in us-west-2 to handle sudden traffic spikes during failover.
- E
Implement Amazon RDS Global Database for faster cross-Region replication and failover.
Show answer and explanation
Correct answers: A, D, E
Explanation
To optimize failover time and ensure minimal downtime in a multi-Region architecture, it's critical to implement solutions that enable automated routing, pre-warming of resources, and faster database replication. Amazon Route 53 with health checks provides automated DNS-level failover between Regions, while pre-warming the secondary Region's ALB ensures it can handle traffic spikes. Additionally, using Amazon RDS Global Database allows for low-latency replication and faster failover, making it an ideal choice for disaster recovery scenarios.
- A. Correct.
Correct. Amazon Route 53 with health checks can automatically detect issues in the primary Region and route traffic to the secondary Region, ensuring high availability and faster failover.
- B. Incorrect.
Incorrect. While Amazon RDS Read Replicas can be promoted to standalone databases, this is a manual process and does not ensure minimal downtime. Using solutions like Multi-AZ or Global Database is more appropriate for automated failover.
- C. Incorrect.
Incorrect. ALB cannot redirect traffic across Regions. Traffic redirection for cross-Regional failover is managed at the DNS level, typically using Route 53.
- D. Correct.
Correct. Pre-warming the ALB in the secondary Region ensures it can handle the incoming traffic during a failover event without latency issues caused by scaling delays.
- E. Correct.
Correct. Amazon RDS Global Database provides faster cross-Region replication and failover capabilities, significantly reducing the time needed to recover after a Regional failure.