- A
Request-based SLI counting good requests divided by total requests
A request-based SLI where a good request is one with latency <=200ms and a non-5xx status fits this scenario.
- B
Availability-based SLI using a rolling window of 30 days
Why wrong: Availability alone does not capture latency; this SLI would only count successful requests regardless of speed.
- C
Window-based SLI counting good minutes
Why wrong: Window-based SLIs measure the proportion of time windows where all requests are good, not the proportion of individual good requests.
- D
Throughput-based SLI measuring requests per second
Why wrong: Throughput measures volume, not quality or speed of responses.
Question 188 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 SRE team wants to define an SLO for a microservice that processes HTTP requests. They need an SLI that measures the proportion of requests that are answered within 200ms with a non-5xx status code. Which type of SLI should they use?
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 SLI counting good requests divided by total requests
A latency-based SLI with a threshold (200ms) combined with availability (non-5xx) is a request-based SLI measuring good requests (fast+successful) over total requests.
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.
- ✓
Request-based SLI counting good requests divided by total requests
Why this is correct
A request-based SLI where a good request is one with latency <=200ms and a non-5xx status fits this scenario.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Availability-based SLI using a rolling window of 30 days
Why it's wrong here
Availability alone does not capture latency; this SLI would only count successful requests regardless of speed.
- ✗
Window-based SLI counting good minutes
Why it's wrong here
Window-based SLIs measure the proportion of time windows where all requests are good, not the proportion of individual good requests.
- ✗
Throughput-based SLI measuring requests per second
Why it's wrong here
Throughput measures volume, not quality or speed of responses.
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.
- →
Applying Site Reliability Engineering Practices to a Service — study guide chapter
Learn the concepts, then practise the questions
- →
Applying Site Reliability Engineering Practices to a Service practice questions
Targeted practice on this topic area only
- →
All PCDE questions
1,000 questions across all exam domains
- →
Google Professional Cloud Database Engineer study guide
Full concept coverage aligned to exam objectives
- →
PCDE practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCDE practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Building and Implementing CI/CD Pipelines for a Service practice questions
Practise PCDE questions linked to Building and Implementing CI/CD Pipelines for a Service.
Bootstrapping a Google Cloud Organisation for DevOps practice questions
Practise PCDE questions linked to Bootstrapping a Google Cloud Organisation for DevOps.
Applying Site Reliability Engineering Practices to a Service practice questions
Practise PCDE questions linked to Applying Site Reliability Engineering Practices to a Service.
Implementing Service Monitoring Strategies practice questions
Practise PCDE questions linked to Implementing Service Monitoring Strategies.
Optimising Service Performance practice questions
Practise PCDE questions linked to Optimising Service Performance.
Plan and manage database infrastructure practice questions
Practise PCDE questions linked to Plan and manage database infrastructure.
Define data structures and implement SQL for Business Intelligence practice questions
Practise PCDE questions linked to Define data structures and implement SQL for Business Intelligence.
Design and implement database schemas practice questions
Practise PCDE questions linked to Design and implement database schemas.
Monitor and optimize database performance practice questions
Practise PCDE questions linked to Monitor and optimize database performance.
PCDE fundamentals practice questions
Practise PCDE questions linked to PCDE fundamentals.
PCDE scenario practice questions
Practise PCDE questions linked to PCDE scenario.
PCDE troubleshooting practice questions
Practise PCDE questions linked to PCDE troubleshooting.
Practice this exam
Start a free PCDE practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
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 SLI counting good requests divided by total requests — A latency-based SLI with a threshold (200ms) combined with availability (non-5xx) is a request-based SLI measuring good requests (fast+successful) over total requests.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.