SAA-C03 Question 194
Select 2An e-commerce company is hosting its web application on Amazon EC2 instances behind an Application Load Balancer (ALB) in a single AWS Region. The company wants to implement a failover strategy to ensure high availability in case the primary Region becomes unavailable. Which of the following solutions will ensure minimal downtime and automatic failover in such a scenario?
- A
Deploy the application in a second AWS Region, configure Route 53 with a failover routing policy, and set health checks for the primary and secondary endpoints.
- B
Set up an Auto Scaling group in the primary Region to automatically replace unhealthy instances.
- C
Use AWS Global Accelerator to automatically route traffic to the nearest healthy Region.
- D
Configure a second ALB in a different Region, replicate the application, and use Route 53 latency-based routing policy to distribute traffic.
- E
Enable Multi-AZ deployments for the ALB to ensure automatic failover across Regions.
Show answer and explanation
Correct answers: A, D
Explanation
Failover strategies for a web application require deploying resources across multiple AWS Regions to ensure availability in case one Region becomes unavailable. Using Route 53 with failover routing and health checks is a common approach to detect Region outages and redirect traffic. Additionally, configuring a second ALB in another Region with Route 53 latency-based routing ensures that traffic can be dynamically routed based on both health and latency, providing a robust failover strategy. Solutions like Auto Scaling and Multi-AZ only enhance resilience within a single Region, and AWS Global Accelerator is not tailored specifically for failover scenarios.
- A. Correct.
This is a correct option. By deploying the application in a second Region and using Route 53 with a failover routing policy, you ensure that traffic is routed to the secondary Region in the event that the primary Region becomes unavailable. Health checks ensure that Route 53 can detect failures and perform failover.
- B. Incorrect.
This is incorrect. While an Auto Scaling group improves resilience within a single Region by replacing unhealthy instances, it does not provide failover across Regions.
- C. Incorrect.
This is incorrect. AWS Global Accelerator can route traffic to the nearest healthy endpoint, but it requires pre-configured endpoints across multiple Regions. It is not specifically designed to handle failover scenarios where an entire Region is unavailable.
- D. Correct.
This is a correct option. Configuring a second ALB in another Region and using Route 53's latency-based routing ensures that traffic can be routed dynamically based on Region health and latency. This strategy enables failover as well as performance optimization.
- E. Incorrect.
This is incorrect. Multi-AZ deployments for ALBs improve availability within a single Region but do not provide failover across Regions.