- A
Availability SLO using a single metric for uptime
Why wrong: Availability SLOs are for uptime, not request success.
- B
Request-based SLO using a single distribution metric
Why wrong: A single metric would require a threshold applied to a histogram, not two separate counters.
- C
Window-based SLO with metric distribution
Why wrong: Window-based uses good minutes per total minutes, not request counts.
- D
Request-based SLO using two metrics (good count / valid count)
The engineer has two metrics: good and total. A request-based SLO calculates the ratio.
Question 426 of 1,000
PCDE Practice Question: Applying Site Reliability Engineering Practices to a Service
This PCDE practice question tests your understanding of applying site reliability engineering practices to a service. 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.
An engineer needs to create an SLO in Cloud Monitoring for a service that processes requests. The SLO should measure the proportion of requests that complete successfully within 300ms. The metric type for successful requests is custom.googleapis.com/myapp/success_count and for total requests is custom.googleapis.com/myapp/total_count. Which type of SLO should they create?
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
✓
Request-based SLO using two metrics (good count / valid count)
Cloud Monitoring SLOs can be request-based using a ratio of good requests to total requests from two metrics. This is a request-based SLO with a metric distribution.
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.
- ✗
Availability SLO using a single metric for uptime
Why it's wrong here
Availability SLOs are for uptime, not request success.
- ✗
Request-based SLO using a single distribution metric
Why it's wrong here
A single metric would require a threshold applied to a histogram, not two separate counters.
- ✗
Window-based SLO with metric distribution
Why it's wrong here
Window-based uses good minutes per total minutes, not request counts.
- ✓
Request-based SLO using two metrics (good count / valid count)
Why this is correct
The engineer has two metrics: good and total. A request-based SLO calculates the ratio.
Related concept
Read the scenario before looking for a memorised answer.
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
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
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.
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Applying Site Reliability Engineering Practices to a Service — study guide chapter
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FAQ
Questions learners often ask
What does this PCDE question test?
Applying Site Reliability Engineering Practices to a Service — This question tests Applying Site Reliability Engineering Practices to a Service — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Request-based SLO using two metrics (good count / valid count) — Cloud Monitoring SLOs can be request-based using a ratio of good requests to total requests from two metrics. This is a request-based SLO with a metric distribution.
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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