AWS Certified Solutions Architect – Associate (SAA-C02) — Question 253

A company has developed a microservices application. It uses a client-facing API with Amazon API Gateway and multiple internal services hosted on Amazon
EC2 instances to process user requests. The API is designed to support unpredictable surges in traffic, but internal services may become overwhelmed and unresponsive for a period of time during surges. A solutions architect needs to design a more reliable solution that reduces errors when internal services become unresponsive or unavailable.
Which solution meets these requirements?

Answer options

• A. Use AWS Auto Scaling to scale up internal services when there is a surge in traffic.
• B. Use different Availability Zones to host internal services. Send a notification to a system administrator when an internal service becomes unresponsive.
• C. Use an Elastic Load Balancer to distribute the traffic between internal services. Configure Amazon CloudWatch metrics to monitor traffic to internal services.
• D. Use Amazon Simple Queue Service (Amazon SQS) to store user requests as they arrive. Change the internal services to retrieve the requests from the queue for processing.

Correct answer: D

Explanation

The correct answer is D, as using Amazon SQS allows requests to be queued and processed asynchronously, which prevents overwhelming the internal services during traffic spikes. Option A focuses on scaling which may not solve the problem of responsiveness under high load. Option B addresses redundancy but does not directly manage traffic surges, and option C deals with load balancing but still risks service unavailability during peak times.