AWS Certified Solutions Architect – Professional (SAP-C02) — Question 470

A company needs to improve the reliability of its ticketing application. The application runs on an Amazon Elastic Container Service (Amazon ECS) cluster. The company uses Amazon CloudFront to serve the application. A single ECS service of the ECS cluster is the CloudFront distribution’s origin.

The application allows only a specific number of active users to enter a ticket purchasing flow. These users are identified by an encrypted attribute in their JSON Web Token (JWT). All other users are redirected to a waiting room module until there is available capacity for purchasing.

The application is experiencing high loads. The waiting room module is working as designed, but load on the waiting room is disrupting the applications availability.
This disruption is negatively affecting the application's ticket sale transactions.

Which solution will provide the MOST reliability for ticket sale transactions during periods of high load?

Answer options

• A. Create a separate service in the ECS cluster for the waiting room. Use a separate scaling configuration. Ensure that the ticketing service uses the JWT information and appropriately forwards requests to the waiting room service.
• B. Move the application to an Amazon Elastic Kubernetes Service (Amazon EKS) cluster. Split the waiting room module into a pod that is separate from the ticketing pod. Make the ticketing pod part of a StatefulSet. Ensure that the ticketing pod uses the JWT information and appropriately forwards requests to the waiting room pod.
• C. Create a separate service in the ECS cluster for the waiting room. Use a separate scaling configuration. Create a CloudFront function that inspects the JWT information and appropriately forwards requests to the ticketing service or the waiting room service.
• D. Move the application to an Amazon Elastic Kubernetes Service (Amazon EKS) cluster. Split the waiting room module into a pod that is separate from the ticketing pod. Use AWS App Mesh by provisioning the App Mesh controller for Kubernetes. Enable mTLS authentication and service-to-service authentication for communication between the ticketing pod and the waiting room pod. Ensure that the ticketing pod uses the JWT information and appropriately forwards requests to the waiting room pod.

Correct answer: C

Explanation

Option C is correct because offloading the JWT parsing and routing logic to a CloudFront function at the edge prevents excess waiting-room traffic from reaching the backend container instances. By decoupling the waiting room into its own ECS service with independent scaling, the system ensures that high waiting-room traffic does not compete for resources with the core ticketing service. Options A, B, and D are less effective because they still require the primary ticketing application container to handle and route the initial high-volume traffic, exposing it to potential resource exhaustion.