AWS Certified Solutions Architect – Professional — Question 444

You have deployed a web application targeting a global audience across multiple AWS Regions under the domain name.example.com. You decide to use
Route53 Latency-Based Routing to serve web requests to users from the region closest to the user. To provide business continuity in the event of server downtime you configure weighted record sets associated with two web servers in separate Availability Zones per region. Dunning a DR test you notice that when you disable all web servers in one of the regions Route53 does not automatically direct all users to the other region.
What could be happening? (Choose two.)

Answer options

• A. Latency resource record sets cannot be used in combination with weighted resource record sets.
• B. You did not setup an HTTP health check to one or more of the weighted resource record sets associated with me disabled web servers.
• C. The value of the weight associated with the latency alias resource record set in the region with the disabled servers is higher than the weight for the other region.
• D. One of the two working web servers in the other region did not pass its HTTP health check.
• E. You did not set "Evaluate Target Health" to "Yes" on the latency alias resource record set associated with example com in the region where you disabled the servers.

Correct answer: B, E

Explanation

For Route53 to successfully failover traffic to another region, it must be able to detect that the local resources in the primary region are unhealthy. This requires having HTTP health checks configured on the individual weighted resource records, and having 'Evaluate Target Health' set to 'Yes' on the parent latency alias record so that it inherits and acts upon the health status of those underlying weighted records.