AWS Certified Solutions Architect – Associate (SAA-C03) — Question 820

A company wants to enhance its ecommerce order-processing application that is deployed on AWS. The application must process each order exactly once without affecting the customer experience during unpredictable traffic surges.

Which solution will meet these requirements?

Answer options

• A. Create an Amazon Simple Queue Service (Amazon SQS) FIFO queue. Put all the orders in the SQS queue. Configure an AWS Lambda function as the target to process the orders.
• B. Create an Amazon Simple Notification Service (Amazon SNS) standard topic. Publish all the orders to the SNS standard topic. Configure the application as a notification target.
• C. Create a flow by using Amazon AppFlow. Send the orders to the flow. Configure an AWS Lambda function as the target to process the orders.
• D. Configure AWS X-Ray in the application to track the order requests. Configure the application to process the orders by pulling the orders from Amazon CloudWatch.

Correct answer: A

Explanation

Amazon SQS FIFO queues are designed to guarantee exactly-once processing and preserve message ordering, which effectively handles unpredictable traffic spikes by decoupling the architecture. Amazon SNS standard topics do not support exactly-once delivery, while Amazon AppFlow is used for integrating SaaS applications rather than application decoupling. AWS X-Ray and Amazon CloudWatch are monitoring and observability services, not queueing or messaging solutions.