AZ-104 Deploy and Manage Azure Compute Practice Question
Exhibit
Scaling requirement: - Workload is stateless - Start with 2 instances - Increase capacity when average CPU stays above 70% for 10 minutes - Decrease capacity when demand drops - All instances should run the same image and configuration
Based on the exhibit, a stateless web app must add VM instances during business hours and remove them at night based on CPU usage. Which Azure service should the administrator deploy?
⚠ Common exam trap
A common mix-up: candidates confuse availability sets (which provide high availability) with scale sets (which provide autoscaling), leading them to pick Option A for a scenario that explicitly requires dynamic scaling based on load and schedule.
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
✓
An Azure virtual machine scale set.
An Azure virtual machine scale set (VMSS) is the correct choice because it automatically scales the number of VM instances in or out based on CPU usage metrics, and it supports scheduled scaling to add instances during business hours and remove them at night. This aligns with the stateless web app requirement for elastic, automated scaling without manual intervention.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
An availability set with two virtual machines.
Why it's wrong here
An availability set distributes two or more VMs across fault domains and update domains to guard against hardware failures and maintenance events. It does not, however, provide any autoscale behavior — the instance count is fixed, so the deployment cannot grow during business hours or shrink when demand drops. For a stateless web app, the correct pattern is a scale set that can change instance count on demand, not a static availability-set-backed pair of VMs.
When this WOULD be correct
A question requiring high availability for a stateless web app with a fixed number of VMs (e.g., two) during all hours, without any scaling requirements. The scenario would emphasize fault tolerance against hardware failures.
- ✓
An Azure virtual machine scale set.
Why this is correct
A virtual machine scale set is designed for identical VM instances that can scale out and scale in automatically. It works well for stateless workloads, and autoscale rules can use CPU thresholds or schedules to adjust capacity over time. This exactly matches the requirement for business-hour scaling.
- ✗
A single Azure VM with a larger size.
Why it's wrong here
Scaling to a larger VM size (vertical scaling) increases the capacity of a single instance, but it does not add compute nodes when demand rises. Because the web app is stateless and needs variable capacity during business hours, the compute layer must be able to add and remove identical instances automatically. A fixed, single VM cannot react to load thresholds or a schedule, and resizing typically requires a restart, causing downtime during peak periods.
- ✗
A recovery services vault.
Why it's wrong here
Azure Recovery Services vault is a management service for storing backups and enabling disaster recovery, such as Azure Backup and Site Recovery. It does not run application code or participate in autoscaling, so it cannot respond to the CPU or schedule-based scaling requirements of a stateless web app. Using this service would not add or remove VM instances in any scenario.
When this WOULD be correct
An administrator needs to protect Azure VMs by enabling backup and restore capabilities, including cross-region restore and soft delete.
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.
✓An Azure virtual machine scale set.Correct answer▾
Why this is correct
A virtual machine scale set is designed for identical VM instances that can scale out and scale in automatically. It works well for stateless workloads, and autoscale rules can use CPU thresholds or schedules to adjust capacity over time. This exactly matches the requirement for business-hour scaling.
✗An availability set with two virtual machines.Wrong answer — click to see why▾
Why this is wrong here
An availability set provides high availability for a fixed number of VMs, but does not support automatic scaling based on CPU usage or schedule. It cannot add or remove instances dynamically.
★ When this WOULD be the correct answer
A question requiring high availability for a stateless web app with a fixed number of VMs (e.g., two) during all hours, without any scaling requirements. The scenario would emphasize fault tolerance against hardware failures.
Why candidates choose this
Candidates may confuse high availability (availability set) with scalability (scale set), or think that adding VMs manually to an availability set can meet scaling needs.
✗A recovery services vault.Wrong answer — click to see why▾
Why this is wrong here
A Recovery Services vault is used for backup and disaster recovery, not for scaling VM instances based on CPU usage or scheduling.
★ When this WOULD be the correct answer
An administrator needs to protect Azure VMs by enabling backup and restore capabilities, including cross-region restore and soft delete.
Why candidates choose this
Candidates may confuse recovery services with scaling or high availability features, or think it can handle automatic instance management.
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?”
Go deeper
Related to this question
About these practice questions
One of 1,049 original AZ-104 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.