AWS Certified Solutions Architect – Professional — Question 139

A Solutions Architect must build a highly available infrastructure for a popular global video game that runs on a mobile phone platform. The application runs on
Amazon EC2 instances behind an Application Load Balancer. The instances run in an Auto Scaling group across multiple Availability Zones. The database tier is an Amazon RDS MySQL Multi-AZ instance. The entire application stack is deployed in both us-east-1 and eu-central-1. Amazon Route 53 is used to route traffic to the two installations using a latency-based routing policy. A weighted routing policy is configured in Route 53 as a fail over to another region in case the installation in a region becomes unresponsive.
During the testing of disaster recovery scenarios, after blocking access to the Amazon RDS MySQL instance in eu-central-1 from all the application instances running in that region. Route 53 does not automatically failover all traffic to us-east-1.
Based on this situation, which changes would allow the infrastructure to failover to us-east-1? (Choose two.)

Answer options

• A. Specify a weight of 100 for the record pointing to the primary Application Load Balancer in us-east-1 and a weight of 60 for the pointing to the primary Application Load Balancer in eu-central-1.
• B. Specify a weight of 100 for the record pointing to the primary Application Load Balancer in us-east-1 and a weight of 0 for the record pointing to the primary Application Load Balancer in eu-central-1.
• C. Set the value of Evaluate Target Health to Yes on the latency alias resources for both eu-central-1 and us-east-1.
• D. Write a URL in the application that performs a health check on the database layer. Add it as a health check within the weighted routing policy in both regions.
• E. Disable any existing health checks for the resources in the policies and set a weight of 0 for the records pointing to primary in both eu-central-1 and us-east-1, and set a weight of 100 for the primary Application Load Balancer only in the region that has healthy resources.

Correct answer: C, D

Explanation

The correct answers, C and D, ensure that health checks are actively monitoring the resources in both regions, allowing Route 53 to determine when to failover based on the health status. Option A does not prioritize us-east-1 appropriately, and option B could prevent traffic from being routed to eu-central-1 entirely. Options E would disable health checks, negating the failover capabilities needed for resilience.