ANS-C01 Question 21
Select 2An organization is using Amazon CloudFront as its Content Delivery Network (CDN) to deliver static and dynamic content globally. They also use an Elastic Load Balancer (ELB) in a single AWS Region to distribute traffic to their backend application servers. The company wants to ensure high availability and global fault tolerance by integrating these services. Which combination of configurations should they implement?
- A
Configure Amazon CloudFront to use an ELB as its origin and enable origin failover to a secondary ELB in a different AWS Region.
- B
Use Amazon Route 53 with geolocation routing to direct traffic from CloudFront to the nearest ELB origin globally.
- C
Configure CloudFront to use multiple origins and set origin groups with failover between primary and secondary origins.
- D
Enable Amazon API Gateway as the origin for CloudFront and configure API Gateway failover across multiple regions.
- E
Deploy an ALB in each AWS Region and configure CloudFront to dynamically select the appropriate ALB based on latency.
Show answer and explanation
Correct answers: A, C
Explanation
To achieve high availability and global fault tolerance with CloudFront and ELB, you need to configure CloudFront to use ELBs as origins and enable origin failover to a secondary ELB in another Region. Additionally, using multiple origins and setting up origin groups with failover ensures redundancy and fault tolerance. Other options such as Route 53 geolocation routing, API Gateway, or latency-based routing are not directly aligned with the use case or require additional configurations.
- A. Correct.
This is a correct approach. Configuring CloudFront to use an ELB as its origin and enabling origin failover ensures that if the primary ELB fails, traffic is routed to a secondary ELB in another Region, achieving high availability and fault tolerance.
- B. Incorrect.
This is incorrect. While Route 53 geolocation routing can be used to route traffic globally, it is not directly integrated with CloudFront to manage origin selection or failover scenarios.
- C. Correct.
This is a correct approach. By configuring CloudFront with multiple origins and using origin groups with failover, traffic can automatically route to an alternate origin (e.g., a secondary ELB in another Region) if the primary origin fails.
- D. Incorrect.
This is incorrect. API Gateway can serve as an origin for CloudFront, but failover across multiple regions would require additional configuration, and it is not as common as using origin failover with ELBs for this use case.
- E. Incorrect.
This is incorrect. While deploying multiple ALBs and dynamically selecting based on latency sounds feasible, CloudFront does not have built-in latency-based origin selection. Route 53 latency-based routing would be required for such a setup.