AZ-900 Describe cloud concepts Practice Test 7 — 15 Questions

Question 1

A company runs several virtual machines on Azure that are hosted on physical servers shared with other customers. The company is concerned that another customer's high workload ('noisy neighbor') could degrade their own application performance. However, Azure's infrastructure ensures that each virtual machine receives a dedicated allotment of CPU and memory resources, and performance remains consistent regardless of the activity of other tenants. Which characteristic of cloud computing does this scenario best illustrate?

Accepted Answer

Resource pooling. Resource pooling is the correct answer because it describes how Azure's multi-tenant architecture allows physical resources (CPU, memory, storage, network) to be shared among multiple customers while ensuring each virtual machine receives a dedicated allocation of resources. This isolation prevents a 'noisy neighbor' scenario from degrading performance, as each VM's resource allotment is guaranteed regardless of other tenants' activity.

Answer

Measured service

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Rapid elasticity

Answer

On-demand self-service

Question 2

A company runs a mission-critical application on Azure virtual machines. The application is hosted in the East US Azure region. To protect against a regional disaster, the company configures Azure Site Recovery to replicate the VMs to a secondary region (West US). If a disaster occurs in East US, the company can initiate a failover to West US and bring the application back online within minutes using the replicated data. Which cloud computing benefit does this scenario best demonstrate?

Accepted Answer

Disaster recovery and business continuity. Option C is correct because Azure Site Recovery provides disaster recovery and business continuity by replicating Azure VMs from the primary region (East US) to a secondary region (West US). In the event of a regional disaster, failover can be initiated to bring the application online within minutes using the replicated data, ensuring minimal downtime and data loss. This directly aligns with the cloud benefit of disaster recovery and business continuity, which focuses on maintaining operations during catastrophic failures.

Answer

Elasticity

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Pay-as-you-go pricing

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Geo-redundancy

Question 3

A company uses Azure to host a web application. The finance team reviews the monthly invoice and notices that the charges are based on the exact number of hours each virtual machine was running, the amount of storage consumed, and the volume of data transferred out of Azure. They did not pay a fixed upfront cost. Which cloud computing characteristic does this billing model best illustrate?

Accepted Answer

Measured service. The billing model described—charging based on exact hours of VM runtime, storage consumed, and data transfer out—directly aligns with the 'measured service' characteristic of cloud computing. This characteristic means cloud providers meter and bill for resource usage at a granular level (e.g., per hour, per GB), with no upfront fixed cost, enabling a pay-as-you-go model. Azure implements this through its usage meters and billing APIs, which track consumption precisely for each resource.

Answer

Rapid elasticity

Answer

Resource pooling

Answer

On-demand self-service

Question 4

A company migrates its on-premises SQL Server database to Azure SQL Database. The company's security team is concerned about who is responsible for applying security updates to the operating system that hosts the database engine. According to the shared responsibility model for cloud computing, who is responsible for patching the operating system of the underlying host?

Accepted Answer

Microsoft (Azure). In the shared responsibility model for Azure SQL Database, Microsoft is responsible for the underlying infrastructure, including the operating system that hosts the database engine. Azure SQL Database is a Platform as a Service (PaaS) offering, where Microsoft manages the host OS, applies security patches, and ensures the physical and virtual environment is secure. The customer is only responsible for data, access management, and database-level configurations.

Answer

The company (customer)

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Both the company and Microsoft share this responsibility

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A third-party managed service provider

Question 5

A company runs a critical transaction processing application on two Azure virtual machines. The infrastructure is designed so that if one virtual machine encounters a hardware failure and stops functioning, the other virtual machine continues to serve traffic without any interruption or loss of service. Which cloud computing characteristic does this design primarily address?

Accepted Answer

Fault tolerance. The design ensures that if one virtual machine fails due to a hardware failure, the other continues serving traffic without any interruption or loss of service. This is the definition of fault tolerance, which eliminates any single point of failure and maintains continuous operation even when a component fails. High availability reduces downtime but may allow brief interruptions during failover, whereas fault tolerance guarantees zero interruption.

Answer

High availability

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Disaster recovery

Answer

Scalability

Question 6

A company runs an e-commerce website on a set of on-premises servers that are fully owned and depreciated. The website experiences predictable traffic surges during seasonal sales. The company plans to migrate to Azure and wants to pay only for the compute and storage resources consumed, with the ability to automatically add virtual machines during sales and remove them afterward. Which characteristic of cloud computing does this scenario best illustrate?

Accepted Answer

Elasticity. Elasticity is the cloud computing characteristic that allows resources to automatically scale out (add virtual machines) during demand spikes like seasonal sales and scale in (remove VMs) when demand drops, aligning with the pay-per-use model. This scenario directly matches elasticity because the company wants to dynamically adjust compute and storage resources in response to predictable traffic surges, paying only for what is consumed.

Answer

High availability

Answer

Fault tolerance

Answer

Disaster recovery

Question 7

A financial services company has an on-premises data center that houses sensitive customer data. Regulatory requirements mandate that this data cannot be stored or processed outside the company's physical premises. However, the company wants to take advantage of cloud computing for compute-intensive risk analysis workloads that process anonymized subsets of the data. The company also needs to maintain a consistent management and security posture across both environments. Which cloud deployment model should the company adopt?

Accepted Answer

Hybrid cloud. Hybrid cloud (C) is correct because it allows the company to keep sensitive customer data on-premises to meet regulatory requirements while leveraging the public cloud for compute-intensive risk analysis on anonymized subsets. This model also enables consistent management and security policies across both environments through unified tools like Azure Arc or AWS Outposts.

Answer

Public cloud

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Private cloud

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Community cloud

Question 8

A company is evaluating moving their workloads to Azure. They currently operate a small on-premises data center. Their IT manager notes that by using Azure, they will benefit from the fact that Microsoft operates many large data centers globally, which allows them to achieve lower network bandwidth costs and hardware procurement discounts. The company will not have to negotiate separate contracts for power and cooling. Which cloud computing concept does this benefit best illustrate?

Accepted Answer

Economies of scale. The scenario describes how Microsoft's global scale of operations—operating many large data centers—enables lower network bandwidth costs and hardware procurement discounts, and eliminates the need for separate power and cooling contracts. This directly illustrates economies of scale, where the average cost per unit decreases as the scale of operations increases, allowing Microsoft to pass these savings to customers. It is not about technical capabilities like availability, elasticity, or agility, but about the cost advantage derived from massive infrastructure investment.

Answer

High availability

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Elasticity

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Agility

Question 9

A company runs a web application on Azure App Service. During a marketing campaign, the application's traffic surges to five times its normal level. The application is configured to automatically add more instances to handle the increased load and then remove them when demand returns to normal. This ability to dynamically provision and de-provision resources based on real-time demand is a direct example of which cloud computing characteristic?

Accepted Answer

Elasticity. The scenario describes automatically adding and removing App Service instances in response to real-time traffic spikes, which is the definition of elasticity. Elasticity is the ability to dynamically scale resources up or down to match demand, ensuring you only pay for what you use. In Azure, this is implemented via autoscale rules that adjust the instance count based on metrics like CPU or request queue length.

Answer

Scalability

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High availability

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Fault tolerance

Question 10

A company is developing a custom web application that will be deployed to Azure. The development team wants to minimize operational overhead and avoid any responsibility for managing the underlying operating system, runtime, or middleware. They want to focus solely on writing application code and managing data. Which cloud service model should the company use for this application?

Accepted Answer

Platform as a Service (PaaS). Platform as a Service (PaaS) is the correct model because it abstracts the underlying OS, runtime, and middleware, allowing developers to focus solely on writing application code and managing data. Azure App Service is a PaaS offering that provides automatic patching, load balancing, and scaling without any responsibility for the host OS or runtime environment. This directly matches the requirement to minimize operational overhead and avoid managing infrastructure layers.

Answer

Infrastructure as a Service (IaaS)

Answer

Software as a Service (SaaS)

Answer

Functions as a Service (FaaS)

Question 11

A company is migrating its on-premises virtual machines (VMs) to Azure using the Infrastructure as a Service (IaaS) model. The VMs run a custom legacy application that requires specific OS-level configurations. The company's IT team wants to understand which party is responsible for applying operating system security patches after the migration. According to the shared responsibility model, who is responsible for patching the OS of the Azure VMs?

Accepted Answer

The company is responsible for patching the operating system on the virtual machines.. In the shared responsibility model for IaaS, the customer retains control over the operating system, including applying security patches. Microsoft manages the physical host, hypervisor, and Azure infrastructure, but the customer is responsible for OS-level configurations and updates on their virtual machines. This applies to both Windows and Linux VMs, regardless of whether the OS is provided by Azure or the customer.

Answer

Microsoft is fully responsible for applying OS patches to the virtual machines.

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Responsibility is shared equally between Microsoft and the company for OS patching.

Answer

Responsibility depends on whether the VM uses Windows or Linux; Microsoft patches Windows VMs and the company patches Linux VMs.

Question 12

A company has traditionally managed on-premises servers for their internal business applications. Setting up a new test environment involves ordering hardware, waiting for delivery, racking, and configuring the OS and applications, which typically takes two to three weeks. The company is migrating their development and testing workloads to Azure. Now, developers can deploy a complete, pre-configured test environment using Azure Resource Manager templates in under two hours. This ability to rapidly provision resources and adapt to changing requirements best illustrates which benefit of cloud computing?

Accepted Answer

Agility. The scenario describes how the company can provision a complete test environment in under two hours using Azure Resource Manager templates, compared to the two-to-three-week on-premises process. This rapid provisioning and ability to quickly adapt to changing requirements is the definition of agility in cloud computing, which focuses on speed, flexibility, and reduced time-to-market for IT resources.

Answer

Scalability

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High availability

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Geographic distribution

Question 13

A company's CFO is evaluating the financial impact of moving the company's on-premises data center to Azure. The on-premises data center requires significant upfront investment for servers, storage, and networking equipment, which is depreciated over several years. In contrast, Azure offers a pay-as-you-go pricing model where the company pays only for the resources it consumes, with no upfront costs. The CFO wants to understand how this shift changes the company's financial reporting. Which statement accurately describes the financial difference between on-premises and cloud spending?

Accepted Answer

On-premises is a capital expenditure (CapEx), while Azure is an operational expenditure (OpEx).. On-premises data centers require significant upfront capital investment for hardware, which is capitalized as a capital expenditure (CapEx) and depreciated over time. Azure's pay-as-you-go model shifts costs to operational expenditure (OpEx), where you pay only for consumed resources with no upfront costs, directly impacting financial reporting by converting fixed costs to variable costs.

Answer

On-premises is an operational expenditure (OpEx), while Azure is a capital expenditure (CapEx).

Answer

Both on-premises and Azure are classified as capital expenditures (CapEx).

Answer

Both on-premises and Azure are classified as operational expenditures (OpEx).

Question 14

A company uses Azure to host a web application. At the end of each month, the finance team receives an invoice that details charges for compute hours, storage consumption, and outbound data transfer. The IT manager explains that this granular billing is possible because Azure continuously monitors resource usage and provides detailed usage data for cost allocation. This capability is a direct example of which essential characteristic of cloud computing as defined by the National Institute of Standards and Technology (NIST)?

Accepted Answer

Measured service. The correct answer is D, Measured service, because the scenario describes Azure's ability to continuously monitor resource usage (compute hours, storage, data transfer) and provide detailed billing data. This aligns with NIST's definition of measured service, where cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). The granular invoice is a direct output of this metering and reporting feature.

Answer

On-demand self-service

Answer

Broad network access

Answer

Resource pooling

Question 15

A company is migrating its on-premises SQL Server databases to Azure SQL Database, which is a Platform as a Service (PaaS) offering. The on-premises IT team is accustomed to manually applying monthly security patches to the SQL Server software. After the migration, the team wants to understand their responsibilities for securing the database. According to the shared responsibility model, which party is responsible for applying security patches to the SQL Server database engine in Azure SQL Database?

Accepted Answer

Microsoft, because Azure SQL Database is a PaaS service where Microsoft manages the database engine.. Azure SQL Database is a Platform as a Service (PaaS) offering where Microsoft manages the underlying infrastructure, including the operating system and the SQL Server database engine. Under the shared responsibility model, Microsoft is responsible for applying security patches to the database engine, while the customer is responsible for securing their data, access controls, and database-level configurations. This frees the customer from manual patching tasks they performed on-premises.

Answer

The customer, because the database engine is a customer-managed application.

Answer

Both the customer and Microsoft share equal responsibility for patching the database engine.

Answer

The customer, but only if the Azure SQL Database is configured with the serverless compute tier.