Task 1.1: Describe cloud computing

• AMicrosoft, because it runs the physical hosts that the VMs are placed on

  Incorrect

  Microsoft does own the physical hosts, but that layer sits below the VM. The Windows Server instance inside the VM belongs to the customer in IaaS.

• BMicrosoft, because the VMs were created from Azure Marketplace images

  Incorrect

  Where an image came from doesn't change who maintains it after deployment. Once the VM runs, its operating system is the customer's to patch.

• CBoth equally, because the Windows Server license is billed through Azure

  Incorrect

  Paying for the license through Azure is a billing arrangement. It doesn't move patching of the guest operating system to Microsoft.

• DThe company, because the guest operating system is part of the stack it runs in IaaS

  Correct

  In IaaS the provider runs the physical hosts, network and datacenter, and the customer manages the operating system, its patches and everything installed on it.

The shared responsibility matrix gives the operating system to the customer in IaaS and to Microsoft in PaaS and SaaS. Running VMs is IaaS, so the company patches Windows Server inside them, while Microsoft looks after the physical hosts, network and datacenter underneath.

• AProtecting the data the organization stores in each service

  Correct

  Customer data stays the customer's responsibility in IaaS, PaaS and SaaS alike, including classifying it and deciding how to protect it.

• BManaging the user accounts and identities that sign in to each service

  Correct

  Creating, managing and removing user accounts is the customer's job in every service type; the provider never decides who your users are.

• CPatching the operating system that each service runs on

  Incorrect

  The operating system moves with the service type: the customer patches it in IaaS, and Microsoft does in PaaS and SaaS.

• DConfiguring the network controls around each service

  Incorrect

  Network controls move toward Microsoft as the service type goes from IaaS to SaaS, so they don't stay with the organization across all three.

• EMaintaining the physical servers that each service runs on

  Incorrect

  Physical hosts are Microsoft's responsibility in IaaS, PaaS and SaaS alike.

Microsoft's responsibility matrix shows the customer always retains its data and its identities and accounts, whatever the service type. The operating system and network controls shift toward Microsoft as you move from IaaS to SaaS, and physical infrastructure is Microsoft's from IaaS upward.

• APublic cloud

  Incorrect

  A third party hosting the hardware doesn't make a cloud public when its resources serve one organization alone.

• BHybrid cloud

  Incorrect

  No public cloud is connected to this environment, so there's nothing for it to be combined with.

• CMulticloud

  Incorrect

  This group uses no public cloud provider at all.

• DPrivate cloud

  Correct

  A private cloud is used by a single entity and can be hosted on site or in a dedicated offsite datacenter, even one run by a third party.

What makes a cloud private is that its resources are dedicated to one organization, not where the servers sit. Microsoft notes that a private cloud may run in your own datacenter or in a dedicated offsite datacenter, potentially run by a third party.

• AHybrid cloud

  Correct

  Hybrid cloud connects private and public clouds, and letting a private cloud surge into public resources for temporary demand is a typical use of it.

• BPrivate cloud

  Incorrect

  A private cloud alone has no Azure capacity in it. The temporary Azure resources take the design beyond a private cloud.

• CPublic cloud

  Incorrect

  The order system's base stays in the retailer's own private cloud, so the design isn't purely public.

• DMulticloud

  Incorrect

  Only one public cloud, Azure, is involved, joined to the retailer's own private cloud.

A hybrid cloud uses public and private clouds in one interconnected environment. Microsoft gives this exact case as an example: a private cloud surges into public cloud resources for increased, temporary demand, and gives them back afterward.

• AResize the VM to a small B-series size each evening, then shut Windows down

  Incorrect

  A smaller size costs less per hour, but a VM shut down from inside the guest is still allocated on its host and still billed for compute.

• BTake a snapshot of the OS disk each evening, then shut Windows down

  Incorrect

  A snapshot is a copy of the disk with its own storage cost. It doesn't release the VM from its host, so compute billing goes on.

• CDeallocate the VM from Azure each evening instead of shutting Windows down

  Correct

  A deallocated VM has released its lease on the host hardware, and Azure doesn't bill a deallocated VM for compute.

• DDetach the data disks each evening, then shut Windows down

  Incorrect

  Detaching data disks doesn't change the VM's power state. Shut down from inside the guest, the VM stays allocated and billed for compute.

Shutting down from inside the guest operating system leaves the VM in the Stopped (allocated) state, which Azure still bills for compute. Deallocating the VM moves it to Stopped (deallocated): it releases its lease on the host hardware and isn't billed for compute, although some related resources keep their own charges.

• AAzure Reservations for that VM size and region, three-year term

  Correct

  Reservations lock in a discount for a specific resource, size and region over one or three years, which suits stable, predictable usage.

• BAzure Spot Virtual Machines for the eight VMs

  Incorrect

  Azure can evict Spot VMs whenever it needs the capacity back, which a production system that can't be interrupted can't accept.

• CPay-as-you-go rates for the eight VMs

  Incorrect

  Pay-as-you-go rates carry no discount, so they cost the most for usage that's known to be steady.

• DAn Azure savings plan for compute with a one-year term

  Incorrect

  For a fixed size and region running steadily, a reservation discounts more than a savings plan, and a one-year term discounts less than three years.

Reservations commit to a specific resource for one or three years in return for a discount of up to 72% off pay-as-you-go. Microsoft notes that reservations deliver deeper discounts than savings plans when usage is stable and predictable, and Spot VMs can be evicted, which this system can't accept.

• AAzure Kubernetes Service

  Incorrect

  AKS keeps a cluster's nodes running, which is far more than a few lines of event-driven code need.

• BAzure App Service

  Incorrect

  An App Service plan is billed for the VM instances it defines, so the team would pay for them on the days without uploads.

• CAzure Functions

  Correct

  Functions are event-driven and serverless: an event wakes the code, it scales with demand, and no resources need to stay provisioned between events.

• DAzure Virtual Machine Scale Sets

  Incorrect

  Scale sets run groups of VMs that the team still manages, and at least one instance normally stays running.

Azure Functions runs code in response to events such as a new blob, a message or a timer, scales automatically, and in its serverless plans charges for the time the code runs. VMs and containers have to be running for an app to work; a function is woken by the event.

• AApplying security patches to the operating system of the instances

  Incorrect

  In PaaS, Microsoft manages the operating systems that host the app, so the team no longer patches them.

• BMaintaining the physical servers and network that host the app

  Incorrect

  Physical hosts and the physical network are Microsoft's responsibility in every cloud service type.

• CSecuring the app's own code and its configuration settings

  Correct

  Applications are shared in PaaS: Microsoft runs the platform, but the customer is responsible for application configuration, code security and access controls.

• DUpdating the web server middleware installed on the instances

  Incorrect

  In PaaS, Microsoft manages the runtime environments and middleware that the app runs on.

Moving from IaaS to PaaS hands the operating system, runtime and middleware to Microsoft. The application itself is a shared area: the platform is Microsoft's, but the code, its settings and who can reach it remain the customer's.

• APrivate cloud

  Incorrect

  A private cloud is dedicated to one organization and needs hardware bought for it, which the shop wants to avoid.

• BHybrid cloud

  Incorrect

  Hybrid cloud connects a private cloud with a public one. The shop has no private environment to connect.

• CPublic cloud

  Correct

  A public cloud is built and run by a third-party provider and is available to anyone who wants to buy its services, with no capital expenditure to scale up.

• DMulticloud

  Incorrect

  Multicloud describes how many providers a company combines, not the shared, pay-per-use model the shop is signing up for.

Public cloud services are open to anyone who wants to purchase them, and that general availability is the key difference from a private cloud. You provision and release resources quickly and pay only for what you use, with no hardware to buy.

• AAs capital expenditure, because the servers are dedicated to the workload

  Incorrect

  Capital expenditure is up-front spending on physical infrastructure. Pay-as-you-go cloud services involve no such purchase.

• BAs operational expenditure, because services are paid for as they're consumed

  Correct

  OpEx is ongoing spending on services over time, and paying for cloud resources as you use them falls into that category.

• CAs capital expenditure, spread across the life of the subscription

  Incorrect

  There's no asset to depreciate: the company rents capacity and releases it when done.

• DAs operational expenditure, starting after the first full year of use

  Incorrect

  Consumption-based spending is operational from the first billing cycle; there's no waiting period.

CapEx is up-front spending on physical infrastructure such as servers, network hardware and datacenter space. OpEx is ongoing spending on services. Because cloud services are paid for as they're consumed, cloud computing is classified as an operational expense.

• AAzure Reservations for a three-year term

  Incorrect

  Reservations discount steady, predictable usage committed for one or three years, not a job that runs a few hours a night.

• BAzure Spot Virtual Machines

  Correct

  Spot VMs use unused Azure capacity at a large discount. Azure can evict them when it needs the capacity back, which this job tolerates.

• CAn Azure savings plan for compute

  Incorrect

  A savings plan discounts a committed hourly spend across eligible services. It doesn't use spare capacity the way Spot does.

• DPay-as-you-go VMs started each night

  Incorrect

  Pay-as-you-go suits short or unpredictable use, but it's priced higher than spare capacity for a workload that tolerates eviction.

Azure Spot Virtual Machines run on unused capacity at significant savings, with no SLA, and can be evicted at any time. They suit interruptible work such as batch processing, dev and test, and large compute jobs that can resume elsewhere.

• AHybrid cloud

  Incorrect

  Hybrid cloud joins a private cloud with a public one. The company has no private environment.

• BPrivate cloud

  Incorrect

  A private cloud is dedicated to one organization, typically on its own or dedicated hardware. Both providers here are public.

• CPublic cloud with a single provider

  Incorrect

  The company uses two providers, not one.

• DMulticloud

  Correct

  Using two or more public cloud providers, with resources and security to manage in each, is a multicloud setup.

In a multicloud scenario you use multiple public cloud providers, perhaps for different features or during a move from one provider to another. Azure Arc can help manage such an environment, but the model itself is multicloud, not hybrid.