Cloud Characteristics – CompTIA A+ 220-1101 – 4.1

A cloud-based service is more than just a remote computing device. In this video, you’ll learn about shared resources, metered services, rapid elasticity, high availability, and more.


There are many different ways to deploy a cloud instance. One way is to use an internal cloud. This means that you are creating resources on your own internal network that will be used for these application deployments. Building your own cloud means that you’ll need somewhere to put all of this equipment, so you’ll need to build out your own data center, you’ll need to have all of your own racks, and that’s where you will install all of the equipment for your internal cloud.

Although there is a cost associated with acquiring all this equipment to begin with, this also means that you do not have to pay anything additional as you go. Since there’s no third party that’s going to bill you for usage on this cloud, you can use as much or as little of this internal cloud as you would like, and it will cost you exactly the same amount of money.

If you’re using an external cloud, then you’re using time that might be on an Amazon, a Microsoft, or some other third-party cloud provider systems. This means that you’re sharing resources that are available on this very large public cloud, and most of this is usually stored in the cloud providers’ data centers, usually multiple data centers around the world.

The cost for this external cloud can vary based on the provider. They may require a large upfront cost, or they may bill you based on how much of the platform you’re using, and you would simply pay as you go. This idea of pay-as-you-go or paying for only the services that you’re using are sometimes referred to as metered cloud services. There might be costs for uploading a file or downloading a file, or maybe simply storing the files on their platform have an ongoing cost associated with that.

This usually means there is a low entry cost, so anyone can take advantage of this platform because you don’t have to pay for anything until you use it. And then you can decide just how much of this platform you’d like to use to match the amount of money you might have in your budget. Some platforms like to give you a fixed cost for everything that you might be using.

For example, you might pay for the ability to upload or download files, and it is a fixed cost every month. This means for the entire month, you can transfer as much data as you would like and still pay that same fixed cost. So if you use platforms like Dropbox or Google Drive, you’re paying a flat fee every month, meaning that this is a non-metered cloud service.

One of the advantages of having a cloud-based application instance is that you’re able to create more instances as the load increases and decrease the number of instances as the load decreases. Often, this building out of additional capacity or removing any excess capacity is all seamless to the end user. They have no idea that you’re making these changes behind the scenes. We refer to this flexibility as “rapid elasticity.”

The cloud gives us a way to instantly create a much larger capacity all by using these built-in technologies that are in a cloud-based environment. Cloud-based platforms also tend to be highly available. That means there is redundancy built into the cloud-based platform, so that if they lose power, they lose a server, or something happens with the infrastructure, there’s always a way to keep everything up and running, because they’ve already created a redundant environment.

If they lose power, there might be a generator to keep the center running. If there is a problem with the network, there may be multiple network lines coming into the building. There are many ways to provide this type of redundancy, and every cloud provider has a different level of redundancy that they might offer. This high availability is an important advantage, especially if you have an application that should always be available to your end users.

If you’ve deployed an application instance to a cloud provider that’s in a data center in one country and then you deploy another application instance to a cloud provider that’s in a different country, then you need some way to make sure that all of this data remains in sync. Many cloud providers have different methods for file synchronization so that you can deploy many different instances wherever it might be in the world, but all of that data is synchronized between all of those different data centers.

The cloud isn’t just used for application instances. You might want to have your entire Windows desktop running in the cloud. You can do that by using Desktop as a Service. With Desktop as a Service, your Windows is running in the cloud, and you can access that Windows desktop from any of your computing devices. So you might have a tablet, a phone, or some other type of computer that allows you to gain access to your desktop that’s running in the cloud.

You’ll sometimes see this referred to as Desktop as a Service, or DaaS. The applications that are running in this cloud-based service are running as a Virtual Desktop Infrastructure, or VDI. This means all you really need is a mouse, a keyboard, and a screen and you will have access to your desktop from anywhere in the world.

Most of what we will see on the tablet that we’re using to access this Windows desktop is a screen share. You’re effectively getting a remote desktop view of that Windows environment. That means that the network connection will be incredibly important if you’re using Desktop as a Service, because everything is happening across the network.

Fortunately, this uses remote desktop technology to send a minimal amount of information between the client and the desktop, but you still need that network connection in order to take advantage of Desktop as a Service. Here’s Desktop as a Service running on Amazon. Amazon’s service is called Workspaces, and I clicked a few buttons and created a Windows workspace all by using Desktop as a Service. This now to me looks like I’m running on a Windows platform, but all of this is actually running on the Amazon cloud.