AWS Certified Solutions Architect – Professional (SAP-C02) — Question 420

A global company has a mobile app that displays ticket barcodes. Customers use the tickets on the mobile app to attend live events. Event scanners read the ticket barcodes and call a backend API to validate the barcode data against data in a database. After the barcode is scanned, the backend logic writes to the database's single table to mark the barcode as used.

The company needs to deploy the app on AWS with a DNS name of api.example.com. The company will host the database in three AWS Regions around the world.

Which solution will meet these requirements with the LOWEST latency?

Answer options

• A. Host the database on Amazon Aurora global database clusters. Host the backend on three Amazon Elastic Container Service (Amazon ECS) clusters that are in the same Regions as the database. Create an accelerator in AWS Global Accelerator to route requests to the nearest ECS cluster. Create an Amazon Route 53 record that maps api.example.com to the accelerator endpoint
• B. Host the database on Amazon Aurora global database clusters. Host the backend on three Amazon Elastic Kubernetes Service (Amazon EKS) clusters that are in the same Regions as the database. Create an Amazon CloudFront distribution with the three clusters as origins. Route requests to the nearest EKS cluster. Create an Amazon Route 53 record that maps api.example.com to the CloudFront distribution.
• C. Host the database on Amazon DynamoDB global tables. Create an Amazon CloudFront distribution. Associate the CloudFront distribution with a CloudFront function that contains the backend logic to validate the barcodes. Create an Amazon Route 53 record that maps api.example.com to the CloudFront distribution.
• D. Host the database on Amazon DynamoDB global tables. Create an Amazon CloudFront distribution. Associate the CloudFront distribution with a Lambda@Edge function that contains the backend logic to validate the barcodes. Create an Amazon Route 53 record that maps api.example.com to the CloudFront distribution.

Correct answer: D

Explanation

Amazon DynamoDB global tables provide fully managed, multi-region, active-active replication, making them ideal for low-latency read and write operations on a single table. Lambda@Edge allows backend validation logic to run at edge locations closest to the users and can connect directly to DynamoDB, whereas CloudFront Functions cannot perform external network calls. Amazon Aurora global databases rely on a single primary writer region, which introduces significant latency for write operations originating from other regions.