CV0-004 Troubleshooting Practice Question
A cloud architect is designing a multi-tier application that must be resilient to the failure of an entire availability zone. Which of the following strategies BEST meets this requirement?
⚠ Common exam trap
CV0-004 often tests whether candidates confuse 'high availability' (auto-scaling, larger instances) with 'fault tolerance' (multi-AZ) — the question specifically requires resilience to an entire AZ failure, which only multi-AZ satisfies.
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
✓
Deploy application instances across three availability zones with a load balancer
Deploying application instances across three availability zones behind a load balancer ensures that the failure of any single AZ does not take down the application. The load balancer distributes traffic to healthy instances in the remaining AZs, providing true AZ-level fault tolerance. Three AZs also satisfy the common cloud best practice of N+1 or 2N redundancy.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Place all instances behind a single load balancer in one zone
Why it's wrong here
A single load balancer in one zone is itself a zone-scoped resource, so an outage removes both the balancer and every instance behind it. This pattern is correct for simple single-zone workloads where cross-zone resilience is not a stated requirement.
- ✗
Implement auto-scaling within the same availability zone
Why it's wrong here
Auto-scaling confined to one availability zone adds capacity but all instances still share that zone's failure domain, so a zone outage takes the tier down. Same-zone scaling is correct when handling variable load, not when surviving the loss of an entire zone.
- ✗
Use larger instance types to handle more load
Why it's wrong here
Larger instance types increase per-instance capacity but remain in one zone, so a zone failure still removes the whole tier. Vertical scaling is correct when a workload is constrained by instance CPU or memory, not when the requirement is surviving an availability zone outage.
- ✓
Deploy application instances across three availability zones with a load balancer
Why this is correct
Spreading instances across three availability zones means a single zone outage leaves two zones serving traffic, and the load balancer health checks route around the failed zone. This satisfies the requirement for resilience to the failure of an entire availability zone, which a single-zone or two-zone design cannot guarantee.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This CV0-004 practice question is part of Courseiva's free CompTIA 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 CV0-004 exam.