Question 624 of 1,546
Cost and Performance OptimizationhardMultiple ChoiceObjective-mapped

SOA-C02 Cost and Performance Optimization Practice Question

This SOA-C02 practice question tests your understanding of cost and performance optimization. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

A SysOps team manages a fleet of EC2 instances used for batch processing. The workload runs daily, taking approximately 6 hours. The instances are launched via an Auto Scaling group using On-Demand instances from a custom AMI. The team has noticed that while the instances are running, the CPU utilization is moderate, but the memory usage is high. After the batch completes, the instances are terminated. The team wants to reduce costs without changing the architecture. Which solution would be MOST cost-effective?

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

Modify the Auto Scaling group to use a mixed instances policy with a percentage of Spot Instances and a fallback to On-Demand.

Option A is correct because Spot Instances can provide significant discounts (up to 90%) for fault-tolerant batch workloads, and the team can use a mixed instances policy with On-Demand as a fallback. Option B (memory optimized instances) would likely increase cost. Option C (reserved instances) is not suitable for short-lived, sporadic workloads. Option D (savings plan) could help but still requires committing to a consistent amount, which may not align with the varying batch size. Option A offers the most flexibility and cost savings.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

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

  • Modify the Auto Scaling group to use a mixed instances policy with a percentage of Spot Instances and a fallback to On-Demand.

    Why this is correct

    Spot Instances are ideal for fault-tolerant workloads like batch processing, offering large discounts.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Use a Compute Savings Plan covering the entire compute usage across the account.

    Why it's wrong here

    Savings Plans require a commitment; the batch workload may not have consistent enough usage to benefit optimally.

  • Change the instance type to a memory-optimized family to reduce the number of instances needed.

    Why it's wrong here

    Memory-optimized instances are more expensive per vCPU; the issue is memory usage, but the workload is moderate CPU, so switching may increase cost.

  • Purchase Reserved Instances for the expected daily usage to get a lower hourly rate.

    Why it's wrong here

    Reserved Instances are best for steady-state, predictable workloads, not for short daily batches that may vary in size.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.

Detailed technical explanation

How to think about this question

This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.
  • Use explanations to understand the rule behind the answer.

TExam Day Tips

  • Underline the problem statement mentally.
  • Watch for words such as best, first, most likely and least administrative effort.
  • Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.

What to study next

Got this wrong? Here's your next step.

Identify which SOA-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

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Related SOA-C02 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this SOA-C02 question test?

Cost and Performance Optimization — This question tests Cost and Performance Optimization — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Modify the Auto Scaling group to use a mixed instances policy with a percentage of Spot Instances and a fallback to On-Demand. — Option A is correct because Spot Instances can provide significant discounts (up to 90%) for fault-tolerant batch workloads, and the team can use a mixed instances policy with On-Demand as a fallback. Option B (memory optimized instances) would likely increase cost. Option C (reserved instances) is not suitable for short-lived, sporadic workloads. Option D (savings plan) could help but still requires committing to a consistent amount, which may not align with the varying batch size. Option A offers the most flexibility and cost savings.

What should I do if I get this SOA-C02 question wrong?

Identify which SOA-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 20, 2026

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This SOA-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SOA-C02 exam.