Q2 — AWS SAA-C03 Ch.17

Question 2 of 89 | ← Chapter 17

Q1302. A company hosts a web application on multiple Amazon EC2 instances. The EC2 instances are in an Auto Scaling group that scales in response to user demand. The company wants to optimize costs for the application but does not want to make any long-term commitments.Which solution will meet these requirements?

Correct Answer: C. Purchase a mix of On-Demand Instances and Spot Instances.

Explanation

Let's analyze each option to determine which one meets the requirements of optimizing costs for a web - application hosted on EC2 instances in an Auto Scaling group without making long - term commitments:Option A: Purchase Dedicated Instances onlyCost optimization: Dedicated Instances are physical EC2 servers dedicated to a single customer. They are more expensive than other instance types because they offer isolation at the hardware level. Using only Dedicated Instances would not optimize costs; instead, it would increase the overall cost of running the web application.Long - term commitment: There is no inherent long - term commitment associated with Dedicated Instances in terms of a fixed - term contract like Reserved Instances, but the high cost makes it an unsuitable option for cost optimization. So, this option does not meet the requirements. Option B: Purchase Reserved Instances with a partial upfront payment Cost optimization: Reserved Instances offer a significant discount compared to On - Demand Instances. However, they require a long - term commitment. Even with a partial upfront payment, you are still locked into a contract for a specific term (usually 1 or 3 years). This goes against the requirement of not making any long - term commitments. So, this option does not meet the requirements. Option C: Purchase a mix of On - Demand Instances and Spot Instances Cost optimization:On - Demand Instances allow you to pay for compute capacity by the hour or second with no long - term commitments. You are charged the full price for the instances as you use them. Spot Instances enable you to bid for spare Amazon EC2 computing capacity at potentially much lower prices compared to On - Demand Instances. By using a mix of On - Demand and Spot Instances, you can take advantage of the lower cost of Spot Instances when available and fall back on On - Demand Instances when Spot Instances are not available or when you need more reliable capacity. This combination can significantly reduce the overall cost of running the web application. Long - term commitment: There are no long - term commitments associated with either On - Demand or Spot Instances. You can scale your usage up or down as needed without being tied to a fixed - term contract. So, this option meets the requirements.Option D: Purchase a mix of On - Demand Instances and Reserved Instances Cost optimization: While this combination can offer some cost savings compared to using only On - Demand Instances, Reserved Instances require a long - term commitment. As mentioned earlier, Reserved Instances are contracted for a specific term (1 or 3 years), which violates the requirement of not making any long - term commitments. So, this option does not meet the requirements. Based on the above analysis, the solution that meets the requirements of optimizing costs for the application without making any long - term commitments is Option C.So, the answer is C.