AWS Certified Developer – Associate — Question 176

A company wants to migrate its web application to AWS and leverage auto scaling to handle peak workloads. The solutions architect determined that the best metric for an auto scaling event is the number of concurrent users.

Based on this information, what should the developer use to auto scale based on concurrent users?

Answer options

• A. An Amazon SNS topic to be invoked when a concurrent user threshold is met
• B. An Amazon Cloudwatch NetworkIn metric
• C. Amazon CloudFront to leverage AWS edge locations
• D. A custom Amazon CloudWatch metric for concurrent users

Correct answer: D

Explanation

The correct answer is D because a custom Amazon CloudWatch metric allows the monitoring of the specific number of concurrent users, which is essential for triggering auto scaling. Option A is incorrect as an SNS topic cannot directly scale resources based on user count. Option B is not suitable since the NetworkIn metric does not relate to user activity, and option C deals with content delivery rather than user scaling.