The answer is to use a global load balancer to route traffic to the closest healthy region, deploy managed instance groups (MIGs) across multiple zones, and configure a regional persistent disk or Cloud SQL for high availability. This combination ensures that if an entire zone fails, the MIG automatically recreates instances in healthy zones, while the stateful database remains accessible via a regional resource, providing both high availability and disaster recovery across zones on Google Cloud. On the Google Professional Cloud Developer exam, this scenario tests your understanding of regional resilience patterns versus zonal single points of failure; a common trap is choosing zonal resources like zonal persistent disks, which cannot survive a zone outage. Remember the memory tip: “Global frontend, regional backend, and a replicated database” — this trio covers traffic routing, compute failover, and data durability, ensuring your application survives any single-zone disaster.
PCD Practice Question: Designing highly scalable, available, and reliable cloud-native applications
This PCD practice question tests your understanding of designing highly scalable, available, and reliable cloud-native applications. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 organization is migrating a critical application to Google Cloud and needs to ensure high availability and disaster recovery. The application runs on Compute Engine and uses a stateful database. Which three design choices should they make? (Choose three.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use managed instance groups distributed across multiple zones.
Option A is correct because managed instance groups (MIGs) distributed across multiple zones provide automatic failover and self-healing for the Compute Engine instances. If a zone fails, the MIG automatically recreates instances in healthy zones, ensuring high availability for the application layer. This aligns with Google Cloud's best practices for regional resilience.
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 managed instance groups distributed across multiple zones.
Why this is correct
MIGs across zones provide auto-healing and high availability.
Related concept
Read the scenario before looking for a memorised answer.
✓
Use regional persistent disks for the database.
Why this is correct
Regional persistent disks synchronously replicate data across zones.
Related concept
Read the scenario before looking for a memorised answer.
✓
Use a global load balancer to route traffic to the closest healthy region.
Why this is correct
Global load balancer provides traffic distribution and failover across regions.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use preemptible VMs to reduce costs for the database layer.
Why it's wrong here
Preemptible VMs can be terminated at any time, not suitable for stateful workloads.
✗
Deploy all instances in a single zone and use snapshots for backup.
Why it's wrong here
Single zone is a single point of failure.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that cost-saving measures like preemptible VMs can be applied to stateful workloads, but the trap here is that preemptible VMs are not guaranteed to run and thus cannot support a stateful database requiring persistent uptime and data integrity.
Detailed technical explanation
How to think about this question
Regional persistent disks replicate data synchronously across two zones within a region, providing an RPO of zero for the database layer. When combined with a global load balancer, traffic is routed to the closest healthy backend, enabling cross-region failover with minimal latency. Under the hood, the global load balancer uses Anycast IPs and Google's global network to direct traffic, while MIGs use health checks to detect instance failure and trigger automatic recreation.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Designing highly scalable, available, and reliable cloud-native applications — This question tests Designing highly scalable, available, and reliable cloud-native applications — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use managed instance groups distributed across multiple zones. — Option A is correct because managed instance groups (MIGs) distributed across multiple zones provide automatic failover and self-healing for the Compute Engine instances. If a zone fails, the MIG automatically recreates instances in healthy zones, ensuring high availability for the application layer. This aligns with Google Cloud's best practices for regional resilience.
What should I do if I get this PCD question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A team is designing a cloud-native application that must be highly available and resilient to zone failures. Which three practices should they follow? (Choose three.)
medium
A.Use a single Load Balancer with multiple backends.
✓ B.Deploy resources across multiple zones.
C.Use zonal managed instance groups with 100% target utilization.
✓ D.Store data in regional persistent disks.
✓ E.Implement health checks and autohealing.
Why B: Option B is correct because deploying resources across multiple zones ensures that the application remains available even if an entire zone fails. In Google Cloud, zones are independent failure domains, and distributing workloads across them is a fundamental pattern for achieving high availability and resilience to zone-level outages.
Last reviewed: Jun 11, 2026
Question Discussion
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This PCD 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 PCD exam.
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