What “the cloud” really means - Azure Tutorial

Now that we've laid some groundwork about the cloud and what cloud computing is at a really high level, let's dig in a little bit and let's talk about what the cloud really means. And we're going to start with this concept of a shared responsibility model. This is a very key component to cloud hosting. And I remember when people first started moving to the cloud and they would say, hey, I've just deployed all of my things to the cloud, all of my computers are in the cloud and everything, I don't have to worry about anything. Everything is the responsibility of the cloud provider now. And that's not true at all. There's always a shared responsibility between you as a consumer of the cloud and the cloud provider. Now certainly there are decisions you can make that can change where that balance is, but that shared responsibility model always remains. Now let's talk about what some of the advantages to the cloud are. Number one, it's flexible and cost efficient. It's flexible in that it's very easy for you to deploy new resources or to manage existing resources, or to delete resources if you don't need them anymore. And this all certainly makes it cost efficient, because it means that you are only paying for those things that you need. You're not paying for a lot of overhead that you don't actually need. What you would do in a typical on-premises or hosted data center scenario, where you're you're paying for a lot of infrastructure that you might not necessarily be utilizing. Also, you get the global presence of the Cloud, and this is important from a couple of different standpoints. Number one, it allows you to be better positioned to comply with regulations that might be specific to a certain country or region, because you can ensure that your resources are hosted in a region that allows you to comply with those regulations but also it means that you can ensure that the information that you're serving to your customers over the Cloud network are located geographically close to them, and there are resources that are available in the Cloud that allow you to do that automatically. It just gives people a better experience as they're using your Cloud application. Also, the cloud allows you to have very fast scaling, and that scaling could be increasing the power of a resource, like adding more cores to a CPU, or having more memory on a virtual machine. It could also mean multiple instances of something. If you need to have two virtual machines, it's very easy for you to add a second one. Now, you can also remove that second one if you don't want to pay for it anymore. So there's fast scaling in both directions. Oftentimes, the Cloud will make this automatic so that you don't have to actually sit and watch things and make decisions on the fly. You can have the Cloud make decisions for you and scale for you automatically. Also, by adopting the Cloud, you can gain access to the expertise of the Cloud provider in areas such as security and availability and performance. If you think about, for example, security, most people are not security experts, so they might not know exactly how to configure things so that they are secure. But by adopting a Cloud presence, you are able to take advantage of the expertise that the Cloud provider has in that area, a lot of which you would get just for free because of the way the cloud is configured but you also have resources available to you that help you configure your deployments in a way that is the most secure. So that's a huge advantage of being in the cloud. Now let's talk about some terms that are important for anyone who is moving to the cloud and we're going to start off with the term region. A region is just a specific geographic location where a Cloud provider operates data centers and all the other facilities that are necessary for implementation of the Cloud. Like for example, in Azure, an Azure region is located in a specific city, and you can actually drive up to that region and see it. It's a fenced off facility that has data centers and all the other things necessary to operate Azure within that region. Now, within a region, we have data centers, which is just a building within a region that houses all the servers and the power facilities and the networking components, all that thing that's necessary to operate the Cloud. We also have Cloud services, which is just a capability that's provided to you by the Cloud platform. There are a lot of different categories of services such as compute, storage, or database services, etc. As a consumer of the Cloud, you just simply use these services on demand without having to actually manage any of the underlying infrastructure. The subscription is the underlying thing that groups all of your Cloud resources together. This is how you're charged for resources in Azure, you're charged for your subscription. Also, the subscription allows you to give other people access to certain resources, we're going to look at some of that later in the course, and apply governance to your resources. A resource, which you may have guessed by now, is just an instance of a Cloud service that is inside of your subscription. The service that we talked about in the third bullet point, is that generic capability provided by the Cloud platform. When you create an instance of one of those services, that is a resource. Agility is the ability for you to quickly respond to a need for change in the Cloud. That could be creating new resources, adjusting existing resources, deleting resources, scaling your resources, etc. All of that is agility. Scalability is the ability to react easily and sometimes automatically to adjusting needs based on load or based on your capacity needs. You might need more virtual machines, fewer virtual machines, more powerful virtual machines, or less powerful virtual machines. All of that is scalability in the Cloud. The fact that you can do it in both directions, so you can scale to a more powerful VM or scale back to a less powerful VM, thereby not spending as much money. Same thing with scaling out to multiple instances. Maybe you've decided at some point you need two virtual machines, but then later on you don't need that second one anymore, so you can remove it. The ability to go in both directions, to scale in both directions very easily is called elasticity. Think of it as a rubber band as you pull it in your hands. Then finally, fault-tolerant. A fault is just a small-scale failure that impacts availability of a Cloud service. For example, a fault might be a network cable failing that's attached to a network switch. That would obviously cause an availability problem for whatever resource relies on that network. When we say that the Cloud is fault-tolerant, what that means is that there are features within the Cloud that allow it to maintain the availability of your resources when these faults occur.