AWS Certified Solutions Architect – Associate (SAA-C02) — Question 494
A company is hosting a three-tier ecommerce application in the AWS Cloud. The company hosts the website on Amazon S3 and integrates the website with an
API that handles sales requests. The company hosts the API on three Amazon EC2 instances behind an Application Load Balancer (ALB). The API consists of static and dynamic front-end content along with backend workers that process sales requests asynchronously.
The company is expecting a significant and sudden increase in the number of sales requests during events for the launch of new products.
What should a solutions architect recommend to ensure that all the requests are processed successfully?
Answer options
- A. Add an Amazon CloudFront distribution for the dynamic content. Increase the number of EC2 instances to handle the increase in traffic.
- B. Add an Amazon CloudFront distribution for the static content. Place the EC2 instances in an Auto Scaling group to launch new instances based on network traffic.
- C. Add an Amazon CloudFront distribution for the dynamic content. Add an Amazon ElastiCache instance in front of the ALB to reduce traffic for the API to handle.
- D. Add an Amazon CloudFront distribution for the static content. Add an Amazon Simple Queue Service (Amazon SQS) queue to receive requests from the website for later processing by the EC2 instances.
Correct answer: D
Explanation
Using Amazon CloudFront to cache static content reduces the load on the backend, while integrating Amazon Simple Queue Service (Amazon SQS) decouples the frontend from the backend workers processing requests asynchronously. This queue-based architecture ensures that sudden spikes in sales requests are safely buffered in Amazon SQS, preventing data loss and allowing the EC2 instances to process the messages at a manageable rate. Other options fail because they either attempt to cache dynamic content inappropriately or do not provide a decoupling mechanism to handle sudden, massive traffic surges reliably.