Question 148 of 1,031

Describe cloud concepts →mediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is reliability, specifically the cloud benefit of recovering from failures and continuing to function. This is correct because an Azure Availability Set protects against hardware and OS failures by distributing virtual machines across separate fault domains and update domains, ensuring a single point of failure does not take down the entire application. The Azure Load Balancer then uses health probes to detect when a VM becomes unavailable and automatically redirects traffic only to healthy instances, creating a seamless failover mechanism. On the AZ-900 exam, this scenario tests your understanding of how built-in redundancy and automatic recovery map to the core cloud concept of reliability, often contrasted with high availability (which focuses on uptime) or scalability. A common trap is confusing reliability with disaster recovery; remember that reliability is about surviving local failures within a region, not recovering from a regional outage. Memory tip: think of the Load Balancer as a traffic cop who only lets cars through to open lanes, while the Availability Set ensures the lanes are on different bridges.

AZ-900 Describe cloud concepts Practice Question

This AZ-900 practice question tests your understanding of describe cloud concepts. 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.

A company hosts a critical line-of-business application on Azure virtual machines. The application must remain available even if a single virtual machine fails due to hardware failure or operating system crash. The company deploys two virtual machines in an Availability Set and configures an Azure Load Balancer to distribute traffic. If one VM becomes unavailable, the Load Balancer automatically redirects traffic to the healthy VM. This configuration primarily demonstrates which benefit of cloud computing?

Question 1mediummultiple choice

Full question →

A
Elasticity – ability to scale resources up and down
Why wrong: Elasticity refers to automatically provisioning and releasing resources to match demand, not to recovering from failures. The scenario focuses on keeping the application running despite a VM failure, not on adjusting capacity.
B
Reliability – ability to recover from failures and continue functioning
Correct. The use of an Availability Set and Load Balancer ensures that the application can tolerate the failure of a single VM and continue serving traffic. This is a direct example of reliability, a key benefit of cloud computing.
C
Security – protection against unauthorized access
Why wrong: Security is about controlling access, encrypting data, and defending against threats. The scenario does not describe any security mechanisms such as firewalls, network security groups, or identity management.
D
Cost efficiency – paying only for consumed resources
Why wrong: Cost efficiency relates to the pay-as-you-go model and avoiding upfront investment. While Azure does offer cost efficiency, this scenario is specifically about ensuring availability through redundancy, not about cost savings.

Full breakdown with real-world context →

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

✓

Reliability – ability to recover from failures and continue functioning

This configuration demonstrates reliability, a core cloud computing benefit, because the combination of an Availability Set and Azure Load Balancer ensures that the application remains operational even when a single VM fails due to hardware or OS issues. The Availability Set spreads VMs across fault domains and update domains to isolate failures, while the Load Balancer uses health probes to detect VM unavailability and redirect traffic only to healthy instances. This built-in redundancy and automatic failover capability directly aligns with the cloud's promise of high availability and fault tolerance.

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.

✗
Elasticity – ability to scale resources up and down
Why it's wrong here
Elasticity refers to automatically provisioning and releasing resources to match demand, not to recovering from failures. The scenario focuses on keeping the application running despite a VM failure, not on adjusting capacity.
✓
Reliability – ability to recover from failures and continue functioning
Why this is correct
Correct. The use of an Availability Set and Load Balancer ensures that the application can tolerate the failure of a single VM and continue serving traffic. This is a direct example of reliability, a key benefit of cloud computing.
Related concept
Read the scenario before looking for a memorised answer.
✗
Security – protection against unauthorized access
Why it's wrong here
Security is about controlling access, encrypting data, and defending against threats. The scenario does not describe any security mechanisms such as firewalls, network security groups, or identity management.
✗
Cost efficiency – paying only for consumed resources
Why it's wrong here
Cost efficiency relates to the pay-as-you-go model and avoiding upfront investment. While Azure does offer cost efficiency, this scenario is specifically about ensuring availability through redundancy, not about cost savings.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates confuse reliability (the ability to recover from failures and continue functioning) with elasticity (scaling), because both involve multiple VMs, but the key distinction is that reliability focuses on fault tolerance and automatic failover, not dynamic scaling based on load.

Trap categories for this question

Scenario analysis trap
Elasticity refers to automatically provisioning and releasing resources to match demand, not to recovering from failures. The scenario focuses on keeping the application running despite a VM failure, not on adjusting capacity.

Detailed technical explanation

How to think about this question

Under the hood, an Azure Availability Set places VMs into different fault domains (up to 3) and update domains (up to 20) to ensure that a hardware failure or planned maintenance affects only a subset of VMs. The Azure Load Balancer uses TCP or HTTP health probes (e.g., probing port 80 every 5 seconds with a 2-second timeout) to monitor VM health; if a probe fails twice consecutively, the VM is removed from the backend pool and traffic is redirected to remaining healthy VMs. In a real-world scenario, this setup is critical for meeting SLAs like 99.95% uptime for multi-VM deployments, as it protects against both unplanned hardware failures and planned OS patching events.

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.

Related AZ-900 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Describe cloud concepts practice questions

Practise AZ-900 questions linked to Describe cloud concepts.

Describe Azure architecture and services practice questions

Practise AZ-900 questions linked to Describe Azure architecture and services.

Describe Azure management and governance practice questions

Practise AZ-900 questions linked to Describe Azure management and governance.

AZ-900 Azure services practice questions

Practise AZ-900 questions linked to AZ-900 Azure services.

AZ-900 pricing and support practice questions

Practise AZ-900 questions linked to AZ-900 pricing and support.

AZ-900 security and compliance practice questions

Practise AZ-900 questions linked to AZ-900 security and compliance.

AZ-900 governance practice questions

Practise AZ-900 questions linked to AZ-900 governance.

Practice this exam

Start a free AZ-900 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

AZ-900 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this AZ-900 question test?

Describe cloud concepts — This question tests Describe cloud concepts — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Reliability – ability to recover from failures and continue functioning — This configuration demonstrates reliability, a core cloud computing benefit, because the combination of an Availability Set and Azure Load Balancer ensures that the application remains operational even when a single VM fails due to hardware or OS issues. The Availability Set spreads VMs across fault domains and update domains to isolate failures, while the Load Balancer uses health probes to detect VM unavailability and redirect traffic only to healthy instances. This built-in redundancy and automatic failover capability directly aligns with the cloud's promise of high availability and fault tolerance.

What should I do if I get this AZ-900 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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

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.

Loading comments…

This AZ-900 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-900 exam.