- A
Reads are available but writes are unavailable until the leader region recovers.
Why wrong: Spanner can elect a new leader from remaining regions, so writes can continue after leader re-election (typically <1 min).
- B
The entire instance becomes unavailable due to loss of quorum.
Why wrong: With nam-eur-asia1, the instance has 3 regions, each with multiple zones. Even with two regions down, the third region can maintain quorum for writes. The instance remains available.
- C
The instance becomes read-only until at least two regions recover.
Why wrong: Spanner requires a majority of replicas for writes, but with 3 regions and multiple zones, a majority can be formed from remaining regions. Writes are possible.
- D
Read and write availability are unaffected because Spanner automatically fails over to remaining regions.
Spanner multi-region with nam-eur-asia1 (3 regions, multiple zones each) can tolerate loss of two regions. The remaining region(s) continue to serve reads and writes, with a brief failover if leader region is lost.
PCDOE Practice Question: Design for Reliability, Scalability, and Disaster Recovery
This PCDOE practice question tests your understanding of design for reliability, scalability, and disaster recovery. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 uses Cloud Spanner multi-region with the nam-eur-asia1 configuration. They experience a regional outage that affects two of the three regions. What is the expected behavior regarding read and write availability?
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
Read and write availability are unaffected because Spanner automatically fails over to remaining regions.
Spanner multi-region with 5+ regions (like nam-eur-asia1 which has 3 regions with multiple zones each) can tolerate the loss of up to two regions while maintaining read/write availability. The remaining region(s) will continue to serve reads and writes. However, if the leader region is lost, a new leader is elected from remaining regions, which may cause a brief write unavailability (RTO <1 min). Spanner guarantees 99.999% availability for multi-region instances.
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.
- ✗
Reads are available but writes are unavailable until the leader region recovers.
Why it's wrong here
Spanner can elect a new leader from remaining regions, so writes can continue after leader re-election (typically <1 min).
- ✗
The entire instance becomes unavailable due to loss of quorum.
Why it's wrong here
With nam-eur-asia1, the instance has 3 regions, each with multiple zones. Even with two regions down, the third region can maintain quorum for writes. The instance remains available.
- ✗
The instance becomes read-only until at least two regions recover.
Why it's wrong here
Spanner requires a majority of replicas for writes, but with 3 regions and multiple zones, a majority can be formed from remaining regions. Writes are possible.
- ✓
Read and write availability are unaffected because Spanner automatically fails over to remaining regions.
Why this is correct
Spanner multi-region with nam-eur-asia1 (3 regions, multiple zones each) can tolerate loss of two regions. The remaining region(s) continue to serve reads and writes, with a brief failover if leader region is lost.
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 PCDOE 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.
- →
Design for Reliability, Scalability, and Disaster Recovery — study guide chapter
Learn the concepts, then practise the questions
- →
Design for Reliability, Scalability, and Disaster Recovery practice questions
Targeted practice on this topic area only
- →
All PCDOE questions
1,000 questions across all exam domains
- →
Google Professional Cloud DevOps Engineer study guide
Full concept coverage aligned to exam objectives
- →
PCDOE practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCDOE practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design and Plan Database Solutions practice questions
Practise PCDOE questions linked to Design and Plan Database Solutions.
Manage Database Solutions practice questions
Practise PCDOE questions linked to Manage Database Solutions.
Migrate Database Solutions practice questions
Practise PCDOE questions linked to Migrate Database Solutions.
Design for Reliability, Scalability, and Disaster Recovery practice questions
Practise PCDOE questions linked to Design for Reliability, Scalability, and Disaster Recovery.
Bootstrapping a Google Cloud organization for DevOps practice questions
Practise PCDOE questions linked to Bootstrapping a Google Cloud organization for DevOps.
Managing service incidents practice questions
Practise PCDOE questions linked to Managing service incidents.
Managing Google Cloud costs practice questions
Practise PCDOE questions linked to Managing Google Cloud costs.
Building and implementing CI/CD pipelines practice questions
Practise PCDOE questions linked to Building and implementing CI/CD pipelines.
Implementing service monitoring strategies practice questions
Practise PCDOE questions linked to Implementing service monitoring strategies.
Optimizing service performance practice questions
Practise PCDOE questions linked to Optimizing service performance.
PCDOE fundamentals practice questions
Practise PCDOE questions linked to PCDOE fundamentals.
PCDOE scenario practice questions
Practise PCDOE questions linked to PCDOE scenario.
Practice this exam
Start a free PCDOE 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 PCDOE question test?
Design for Reliability, Scalability, and Disaster Recovery — This question tests Design for Reliability, Scalability, and Disaster Recovery — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Read and write availability are unaffected because Spanner automatically fails over to remaining regions. — Spanner multi-region with 5+ regions (like nam-eur-asia1 which has 3 regions with multiple zones each) can tolerate the loss of up to two regions while maintaining read/write availability. The remaining region(s) will continue to serve reads and writes. However, if the leader region is lost, a new leader is elected from remaining regions, which may cause a brief write unavailability (RTO <1 min). Spanner guarantees 99.999% availability for multi-region instances.
What should I do if I get this PCDOE question wrong?
Identify which PCDOE 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 PCDOE 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 PCDOE 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.