SAP-C02 Question 498
Select 2A company runs a mission-critical web application on AWS that requires high availability and resiliency. The application is deployed across multiple Availability Zones (AZs) using an Auto Scaling group behind an Application Load Balancer (ALB). Recently, the company experienced a regional outage, and the application became unavailable. What should you do to redesign the architecture to increase its resiliency while ensuring it remains highly available?
- A
Deploy the application in multiple AWS Regions and configure Route 53 with a failover routing policy.
- B
Increase the number of instances in the Auto Scaling group within the current AWS Region.
- C
Enable multi-AZ for the ALB to automatically failover to another Region during a regional outage.
- D
Use an Amazon S3 bucket configured for static website hosting as a backup for the application.
- E
Implement Amazon RDS with a cross-Region read replica for the application's database.
Show answer and explanation
Correct answers: A, E
Explanation
To achieve high availability and resiliency, the application must be deployed across multiple AWS Regions to mitigate the impact of a regional outage. Route 53 with a failover routing policy ensures traffic is directed to a healthy Region. Additionally, implementing a cross-Region read replica for Amazon RDS ensures database availability in the secondary Region, maintaining the application's functionality during region-wide failures.
- A. Correct.
Deploying the application in multiple AWS Regions and using Route 53 with a failover routing policy ensures that if one Region becomes unavailable, traffic can automatically be directed to a secondary Region, improving resiliency.
- B. Incorrect.
Increasing the number of instances in the Auto Scaling group within the same Region does not address a regional outage, as all instances in the Region would be affected.
- C. Incorrect.
The ALB does not support cross-Region failover. Multi-AZ is designed for high availability within a single Region, not across Regions.
- D. Incorrect.
Using an Amazon S3 bucket for static website hosting may provide a temporary backup, but it does not fully replicate the functionality of a dynamic web application.
- E. Correct.
Using Amazon RDS with a cross-Region read replica ensures that the database can be replicated to another Region, improving resiliency in the event of a regional outage.