AWS Certified SysOps Administrator – Associate (legacy) — Question 822

A corporate website is hosted on several Amazon EC2 instances across multiple regions around the globe.
How should an Administrator configure the website to maintain high availability with minimal downtime if one of the regions has network connectivity congestion for an extended period of time?

Answer options

• A. Create an Elastic Load Balancer in front of all the Amazon EC2 instances.
• B. Create an Elastic Load Balancer that fails over to the secondary site when the primary site is not reachable.
• C. Create an Amazon Route 53 Latency Based Routing Record Set that resolves to an Elastic Load Balancer in each region. Set an appropriate health check on each ELB.
• D. Create an Amazon Route 53 latency Based Routing Record Set that resolves to Elastic Load Balancers I each region and has the Evaluate Target Health flag set to ג€trueג€.

Correct answer: D

Explanation

Using Amazon Route 53 Latency Based Routing with "Evaluate Target Health" set to "true" allows Route 53 to inherit the health status of the Elastic Load Balancers in each region and stop routing traffic to a region experiencing issues. This ensures high availability because Route 53 automatically diverts traffic to healthy regions without relying on manual intervention. Other options like a single Elastic Load Balancer cannot span multiple regions, and Route 53 requires the "Evaluate Target Health" flag to properly respond to ELB health status changes.