AWS Certified Cloud Practitioner (CLF-C02) — Question 581

A company is running a reporting web server application on Amazon EC2 instances. The application runs once every week and once again at the end of the month. The EC2 instances can be shut down when they are not in use.

What is the MOST cost-effective billing model for this use case?

Answer options

Correct answer: D

Explanation

On-Demand Instances are the most cost-effective option here because the workload is highly intermittent, allowing instances to be stopped when not in use so the company only pays for the exact hours of compute consumed. Standard and Convertible Reserved Instances require a 1- or 3-year commitment and are designed for continuous workloads, which would result in paying for idle capacity. On-Demand Capacity Reservations reserve capacity but still bill you for the instance duration regardless of whether the instances are running, offering no cost savings for this scenario.