- A
Use committed use discounts for the stateful services
Committed use discounts provide up to 70% discount for predictable workloads.
- B
Enable node auto-provisioning in GKE
Why wrong: Node auto-provisioning automates node creation but does not directly reduce costs without right-sizing.
- C
Use preemptible VMs for the batch jobs
Preemptible VMs are significantly cheaper and suitable for fault-tolerant workloads.
- D
Replace all instances with larger machines to reduce total instance count
Why wrong: This may not reduce costs; larger instances are more expensive per hour.
- E
Use CPU always on for all instances
Why wrong: CPU always on is a Cloud Run feature, not applicable to Compute Engine.
Question 39 of 1,000
PCDE Optimising Service Performance Practice Question
This PCDE practice question tests your understanding of optimising service performance. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 company wants to optimize costs for their Compute Engine instances. They have a mix of workloads: some are fault-tolerant batch jobs, and others are stateful services requiring consistent uptime. Which two strategies should they use to reduce costs? (Choose two.)
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 committed use discounts for the stateful services
Preemptible VMs are cheaper and ideal for fault-tolerant batch jobs. Committed use discounts (1 or 3 years) offer significant savings for stateful services that run continuously. Active Assist recommendations help right-size instances. Using larger instances with fewer VMs may not always save costs. CPU always on is a Cloud Run setting, not relevant to Compute Engine cost optimization.
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.
- ✓
Use committed use discounts for the stateful services
Why this is correct
Committed use discounts provide up to 70% discount for predictable workloads.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Enable node auto-provisioning in GKE
Why it's wrong here
Node auto-provisioning automates node creation but does not directly reduce costs without right-sizing.
- ✓
Use preemptible VMs for the batch jobs
Why this is correct
Preemptible VMs are significantly cheaper and suitable for fault-tolerant workloads.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Replace all instances with larger machines to reduce total instance count
Why it's wrong here
This may not reduce costs; larger instances are more expensive per hour.
- ✗
Use CPU always on for all instances
Why it's wrong here
CPU always on is a Cloud Run feature, not applicable to Compute Engine.
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 PCDE 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.
- →
Optimising Service Performance — study guide chapter
Learn the concepts, then practise the questions
- →
Optimising Service Performance practice questions
Targeted practice on this topic area only
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FAQ
Questions learners often ask
What does this PCDE question test?
Optimising Service Performance — This question tests Optimising Service Performance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use committed use discounts for the stateful services — Preemptible VMs are cheaper and ideal for fault-tolerant batch jobs. Committed use discounts (1 or 3 years) offer significant savings for stateful services that run continuously. Active Assist recommendations help right-size instances. Using larger instances with fewer VMs may not always save costs. CPU always on is a Cloud Run setting, not relevant to Compute Engine cost optimization.
What should I do if I get this PCDE question wrong?
Identify which PCDE 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.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jul 4, 2026
This PCDE practice question is part of Courseiva's free Google Cloud 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 PCDE exam.
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