SOA-C02 Cost and Performance Optimization Practice Question

A SysOps administrator is optimizing costs for an AWS account. The account has multiple EC2 instances running 24/7 with varying utilization. Which TWO actions will help reduce costs without impacting performance? (Choose TWO.)

⚠ Common exam trap

A common mix-up: candidates confuse operational safeguards (like termination protection or monitoring) with cost optimization actions, leading candidates to select options that add cost or provide no savings.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Use AWS Compute Optimizer to right-size instances.

AWS Compute Optimizer analyzes historical utilization metrics (CPU, memory, network, etc.) and provides right-sizing recommendations to match instance types to actual workload demands. By downsizing over-provisioned instances, you reduce costs without degrading performance, as the new instance type still meets the workload's peak requirements.

Answer analysis

Option-by-option breakdown

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

✓
Use AWS Compute Optimizer to right-size instances.
Why this is correct
AWS Compute Optimizer is a machine-learning-based service that analyzes your instance utilization (CPU, memory, network, and disk) over the previous 14 days or longer, and generates right-sizing recommendations that match instance type and size to actual workload requirements. By migrating to recommended smaller or more modern instance families, you eliminate over-provisioning and reduce monthly EC2 costs without degrading application performance, making it a direct and effective cost-optimization action.
✗
Use larger instance types to improve performance.
Why it's wrong here
Selecting larger instance types to boost performance is a scaling approach that increases hourly on-demand rates and typically worsens the waste that arises from idle or underutilized capacity. Without first analyzing actual utilization, larger instances simply raise your baseline costs and do not address the root cause of suboptimal resource usage, so this is not a valid cost-optimization strategy.
✗
Enable detailed CloudWatch monitoring for all instances.
Why it's wrong here
Detailed CloudWatch monitoring (1-minute metric frequency) incurs an additional per-instance charge for every metric, which can significantly increase monitoring costs across all EC2 instances. Standard monitoring at 5-minute frequency is free, and while detailed monitoring may be useful for specific critical workloads, enabling it for every instance does not optimize costs and can materially inflate your monthly bill.
✗
Enable termination protection on all instances.
Why it's wrong here
Termination protection is a lifecycle feature that prevents an EC2 instance from being accidentally terminated via the console, CLI, or API, but it has zero effect on instance pricing or your overall bill. It neither reduces usage nor alters the on-demand or reserved pricing model, so enabling termination protection provides no cost savings and is irrelevant for cost optimization.
✓
Purchase Reserved Instances for instances that run consistently.
Why this is correct
Reserved Instances (RIs) are a billing discount mechanism that, when you commit to a one- or three-year term, can reduce the hourly cost of consistently running instances by up to 72% compared to on-demand pricing. For workloads with predictable, steady-state utilization (e.g., production web servers or databases that run 24/7), purchasing RIs or Savings Plans is one of the most impactful ways to lower EC2 spend while maintaining the exact same instance configuration.

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SOA-C02 Cost and Performance Optimization Practice Question

Why each option matters

Option-by-option breakdown

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