SOA-C02 Cost and Performance Optimization Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Purchase Compute Savings Plans for a 1-year or 3-year term with a commitment that covers the expected compute spend.

  Why this is correct

  Compute Savings Plans are the right choice for a mixed EC2 and Fargate environment because the hourly commitment automatically applies to eligible compute usage across EC2 instances, Fargate tasks, and Lambda functions within the chosen region. Unlike EC2 Instance Savings Plans, they do not lock you to an instance family or size, so you can change instance types or refactor to containers without losing the discounted rate. A 1-year or 3-year term with a commitment that matches steady-state spend yields significant savings over On-Demand.

• ✗

  Purchase EC2 Instance Savings Plans for the most commonly used instance family and region.

  Why it's wrong here

  EC2 Instance Savings Plans are the wrong choice here because they require you to commit to a specific instance family (e.g., m5) in a specific region, and the discount applies only to EC2 instances matching that exact combination. Fargate task usage is completely excluded from this plan, so your container workloads would continue to be billed at full On-Demand rates. The lack of flexibility also becomes a problem if you need to move to a different instance family, change sizes, or adopt a different architecture over the term.

• ✗

  Purchase Standard Reserved Instances for the EC2 instances and convert Fargate tasks to use Spot Instances.

  Why it's wrong here

  Standard Reserved Instances are a poor option because they are EC2-only purchase contracts that provide no discount on Fargate usage, meaning the Fargate portion of your workload would still pay full price. Recommending that you convert Fargate tasks to Spot Instances is not a single purchasing option at all; Spot Instances are an interruption-prone pricing model unsuitable for steady-state workloads unless they are fault-tolerant. This mixed approach cannot provide the unified, commitment-based discount you need across both EC2 and Fargate.

• ✗

  Use On-Demand instances for both EC2 and Fargate because the administrator does not want to make a commitment.

  Why it's wrong here

  Using On-Demand for both EC2 and Fargate is the most expensive approach and ignores the fact that your workloads are steady and predictable. A Compute Savings Plan would require only a modest hourly commitment while delivering substantial discounts, often up to 66% compared to On-Demand pricing. Choosing On-Demand simply to avoid any commitment forgoes significant cost savings for no technical benefit, especially when your steady-state usage makes a 1-year or 3-year commitment a low-risk optimization.

Go deeper

Related to this question