SAA-C03 Question 432
Single answerA startup is running a web application on Amazon EC2 instances. The application has variable traffic patterns, with high traffic during the day and minimal usage at night. Cost optimization is a top priority for the startup. Which compute solution should you recommend?
- A
Use On-Demand instances for all application traffic.
- B
Use Reserved Instances for all application traffic.
- C
Use Spot Instances for all application traffic.
- D
Use Auto Scaling with a mix of On-Demand and Spot Instances.
Show answer and explanation
Correct answer: D
Explanation
The best solution for the startup is to use Auto Scaling with a mix of On-Demand and Spot Instances. Auto Scaling dynamically adjusts the number of running instances based on traffic, ensuring cost efficiency during low-usage periods. Spot Instances provide significant cost savings for non-critical workloads, while On-Demand Instances ensure reliability for critical components. This approach balances cost optimization with application reliability.
- A. Incorrect.
Using On-Demand instances for all application traffic is flexible but not cost-efficient for variable workloads, as they are charged at a fixed hourly rate.
- B. Incorrect.
Reserved Instances are cost-effective for steady-state workloads, but they lack flexibility for handling variable traffic patterns and are not suitable for the startup's needs.
- C. Incorrect.
Spot Instances are highly cost-effective but can be interrupted, making them unsuitable for handling all application traffic, especially if the application has critical components.
- D. Correct.
Using Auto Scaling with a mix of On-Demand and Spot Instances is cost-optimized and appropriate for variable workloads. Auto Scaling ensures capacity is adjusted dynamically, and Spot Instances reduce costs while On-Demand Instances handle critical traffic.