I introduced Cloud Native Application Design and Cloud Computing in the last post. As a next step, we will discuss cloud computing a little more. Understanding cloud computing is the first step toward generating cloud-native applications.
So what is cloud computing? Cloud computing is a term we use to collectively call services provided by cloud service providers. These services include storage, compute, networking, security, etc. Let me borrow the official definition from Wikipedia.
Cloud computing is the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each location being a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a “pay-as-you-go” model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users.https://en.wikipedia.org/wiki/Cloud_computing
The definition covers a few important aspects.
On-Demand: You can activate or deactivate the services as per your need. You are renting the services and not buying any hardware. For example, you can activate/rent a Virtual Machine on the cloud, use it, and then kill it (you take compute capacity from the cloud pool and return it back when you are done).
Multiple Types of services: The definition talks about Compute and Storage (these are basic, and one can argue most services are built on these), but if you go to any popular cloud service provider’s portal, you will see a much larger set of services like databases, security services, AI/ ML based, IOT, etc.
Data Centers: Cloud service providers have multiple data centers, spread across various geographical regions in the world, each region has multiple data centers (usually distributed into zones, with one zone having multiple data centers). This kind of setup helps in replicating resources for scalability, availability, and performance.
Shared Resources: As already mentioned, when on the cloud, you do not own resources and share infrastructure with other users (though cloud providers also have an option for separated infrastructure at a higher price). This helps cloud providers manage the resources at scale, hence keeping the prices low.
Pay-as-you-go: Probably one of the most important factors for the popularity of the cloud. You pay for your usage only. Going back to our previous example, you created a VM for X amount of time, so you pay only for that time.
Unexpected Operating Expenses: Though Cloud is popular because it can help reduce overall infrastructure costs, it can also go the other way if you are not careful about managing your resources. For example, unused resources or unused capacity will add to your bills, at the same time, low capability resources will impact services and user experience. So striking the correct balance becomes important and needs expertise, hence adding to operating costs.