- A
Availability set
Why wrong: An availability set improves resiliency, but it does not automatically scale VM count based on demand.
- B
Virtual machine scale set
A virtual machine scale set supports automatic instance scaling and distributes instances for better platform resilience.
- C
Availability zone
Why wrong: A zone choice improves datacenter resilience, but it does not provide automatic scale out and scale in behavior.
- D
Proximity placement group
Why wrong: A proximity placement group reduces latency between resources, but it is not an autoscaling feature.
Question 112 of 1,170
Azure Virtual Machine Scale Sets: Autoscale and Fault Domain Distribution
This AZ-104 practice question tests your understanding of deploy and manage azure compute. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 stateless API runs on Azure VMs and experiences unpredictable traffic spikes during the day. The administrator must automatically add or remove identical VM instances based on CPU usage, and the platform should distribute instances across fault domains without manual placement. What should be used?
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
✓
Virtual machine scale set
Virtual machine scale sets (VMSS) automatically manage identical VM instances and can scale out/in based on CPU usage metrics via autoscale rules. They distribute instances across fault domains automatically without manual placement, ensuring high availability during unpredictable traffic spikes.
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 set
Why it's wrong here
An availability set improves resiliency, but it does not automatically scale VM count based on demand.
When this WOULD be correct
A question requiring manual placement of VMs across fault domains for high availability without autoscaling, such as: 'You need to deploy two VMs running a legacy application that must be in different fault domains to meet an SLA. What should you use?'
- ✓
Virtual machine scale set
Why this is correct
A virtual machine scale set supports automatic instance scaling and distributes instances for better platform resilience.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Availability zone
Why it's wrong here
A zone choice improves datacenter resilience, but it does not provide automatic scale out and scale in behavior.
When this WOULD be correct
A question requiring high availability and resilience against data center failures, such as deploying a critical application that must remain available even if an entire Azure data center goes down, and where manual placement across zones is acceptable.
- ✗
Proximity placement group
Why it's wrong here
A proximity placement group reduces latency between resources, but it is not an autoscaling feature.
When this WOULD be correct
A question requiring low-latency communication between VMs in the same region, such as for a high-performance computing (HPC) application or a tightly coupled workload, where VMs must be placed close together to minimize network latency.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-104 exam frequently reuses these exact scenarios with slightly different constraints.
✓Virtual machine scale setCorrect answer▾
Why this is correct
A virtual machine scale set supports automatic instance scaling and distributes instances for better platform resilience.
✗Availability setWrong answer — click to see why▾
Why this is wrong here
An availability set does not provide automatic scaling or instance addition/removal based on CPU usage; it only ensures high availability by distributing VMs across fault and update domains within a single set.
★ When this WOULD be the correct answer
A question requiring manual placement of VMs across fault domains for high availability without autoscaling, such as: 'You need to deploy two VMs running a legacy application that must be in different fault domains to meet an SLA. What should you use?'
Why candidates choose this
Candidates may confuse availability sets with scale sets because both involve distributing VMs, but they overlook that availability sets lack autoscaling capabilities.
✗Availability zoneWrong answer — click to see why▾
Why this is wrong here
Availability zones are physically separate data centers within a region, providing high availability and disaster recovery, but they do not automatically scale VM instances based on CPU usage or distribute instances across fault domains without manual placement.
★ When this WOULD be the correct answer
A question requiring high availability and resilience against data center failures, such as deploying a critical application that must remain available even if an entire Azure data center goes down, and where manual placement across zones is acceptable.
Why candidates choose this
Candidates may confuse availability zones with scale sets because both involve distributing VMs, but zones focus on fault isolation at the data center level, not on autoscaling or automatic fault domain distribution.
✗Proximity placement groupWrong answer — click to see why▾
Why this is wrong here
Proximity placement groups reduce network latency between VMs but do not provide autoscaling, load distribution across fault domains, or automatic instance management based on CPU usage.
★ When this WOULD be the correct answer
A question requiring low-latency communication between VMs in the same region, such as for a high-performance computing (HPC) application or a tightly coupled workload, where VMs must be placed close together to minimize network latency.
Why candidates choose this
Candidates may confuse proximity placement groups with availability sets or scale sets, thinking they also handle distribution and scaling, or they may focus on the 'placement' aspect without considering the autoscaling requirement.
Analysis generated from the official AZ-104blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse availability sets with scale sets, thinking an availability set can also handle automatic scaling, but availability sets only provide fault domain distribution for a static set of VMs and lack autoscaling capabilities.
Detailed technical explanation
How to think about this question
VMSS uses a scale-out policy based on Azure Monitor autoscale rules, which can trigger when CPU usage exceeds a threshold (e.g., 75%) for a defined period. Under the hood, VMSS leverages a virtual machine scale set model that automatically places new instances across fault domains (up to 3) and update domains, ensuring resilience without manual configuration. In a real-world scenario, a stateless API handling unpredictable traffic can use VMSS with a custom autoscale profile to add instances during spikes and remove them during lulls, while the platform handles distribution across fault domains.
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
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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Deploy and Manage Azure Compute — study guide chapter
Learn the concepts, then practise the questions
- →
Deploy and Manage Azure Compute practice questions
Targeted practice on this topic area only
- →
All AZ-104 questions
1,170 questions across all exam domains
- →
AZ-104 study guide
Full concept coverage aligned to exam objectives
- →
AZ-104 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related AZ-104 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Manage Azure Identities and Governance practice questions
Practise AZ-104 questions linked to Manage Azure Identities and Governance.
Implement and Manage Storage practice questions
Practise AZ-104 questions linked to Implement and Manage Storage.
Deploy and Manage Azure Compute practice questions
Practise AZ-104 questions linked to Deploy and Manage Azure Compute.
Implement and Manage Virtual Networking practice questions
Practise AZ-104 questions linked to Implement and Manage Virtual Networking.
Monitor and Maintain Azure Resources practice questions
Practise AZ-104 questions linked to Monitor and Maintain Azure Resources.
AZ-104 Azure RBAC practice questions
Practise AZ-104 questions linked to AZ-104 Azure RBAC.
AZ-104 storage account practice questions
Practise AZ-104 questions linked to AZ-104 storage account.
AZ-104 virtual network practice questions
Practise AZ-104 questions linked to AZ-104 virtual network.
AZ-104 NSG practice questions
Practise AZ-104 questions linked to AZ-104 NSG.
AZ-104 Azure Monitor practice questions
Practise AZ-104 questions linked to AZ-104 Azure Monitor.
AZ-104 backup practice questions
Practise AZ-104 questions linked to AZ-104 backup.
AZ-104 managed identity practice questions
Practise AZ-104 questions linked to AZ-104 managed identity.
Practice this exam
Start a free AZ-104 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 AZ-104 question test?
Deploy and Manage Azure Compute — This question tests Deploy and Manage Azure Compute — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Virtual machine scale set — Virtual machine scale sets (VMSS) automatically manage identical VM instances and can scale out/in based on CPU usage metrics via autoscale rules. They distribute instances across fault domains automatically without manual placement, ensuring high availability during unpredictable traffic spikes.
What should I do if I get this AZ-104 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 →
Same concept, more angles
1 more ways this is tested on AZ-104
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. You need to deploy 20 identical Azure virtual machines that host the same web application. The solution must support automatic scale-out based on CPU usage and should minimize administrative overhead. What should you deploy?
medium- A.20 individual virtual machines in the same resource group.
- ✓ B.A Virtual Machine Scale Set.
- C.An availability set.
- D.Azure Container Instances.
Why B: A Virtual Machine Scale Set (VMSS) is the correct choice because it automates the deployment and management of identical VMs, supports autoscaling based on CPU usage metrics, and minimizes administrative overhead by handling VM creation, load balancing, and scaling policies as a single resource. This aligns with the requirement for 20 identical VMs with automatic scale-out based on CPU usage.
Keep practising
More AZ-104 practice questions
- A storage automation service principal must upload, read, and delete blob data in one container by using Microsoft Entra…
- A subnet contains several application servers. You need to allow inbound TCP 3389 only from a management subnet named Su…
- A subscription admin wants to investigate who changed a resource and also review the platform-generated events for that…
- Based on the exhibit, which Azure feature should the administrator use to track this kind of platform-wide service issue…
- An administrator wants a script running on an Azure VM to create a resource in Azure without storing any passwords or cl…
- A PowerShell script runs on an Azure VM every night and uses Azure CLI commands to create tags and VM resources in anoth…
Last reviewed: Jun 11, 2026
This AZ-104 practice question is part of Courseiva's free Microsoft 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 AZ-104 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.