Cloud Computing Part 2- Deployment models(public, private, hybrid, multi cloud)

In my previous article I wrote about what is cloud in general and why we need / should use the cloud combining it with the business strategy.

You might like to start reading part 1 first, for a general overview and continue with this post.

In this one, I will try to explain the cloud deployment types, which are basically public, private, hybrid and multi cloud models. 

Each type has different impact on your technical landscape. However, this decision is not only technical because the chosen model (may not be only one model) has impacts on the business decisions / options; it can affect some areas like legal, finance areas etc.

You have to know that independent from whichever model you use in the cloud, you get most of the common business benefits from the cloud strategy. In all of the models you are going to use technologies like virtualization, cloud automation, APIs with different levels of utilization. 

However not everything is the same.

Let's have a look at these models in detail:

1. PUBLIC CLOUD

Public cloud is the model that comes to people's minds when it is said "Cloud".

It's the model where your computing is done somewhere outside of your "on-premises" landscape; mostly somewhere that you don't even know physically. (of course, providers give you information regarding the location :)

It's the model that is provided by big brothers like AWS by Amazon, Azure by Microsoft, Google Cloud by Google, Alibaba Cloud, IBM Cloud etc.

In this model services are owned and operated by third part providers and shared by multiple customer which provides a low(er) cost structure.

Services are maintained by the provider, therefore easier for the customers.

In public cloud pay-is-you-go is usually the model that is being used, therefore it's more flexible financially.

However, this model is said to be less flexible as the customer has very little control over the system. And also "named" to be less secure as it's shared by multiple customers. But as it's managed by providers employing many professionals" focusing on security specifically, it may even be more secure than an environment managed by customers' own IT staff. Point to reconsider. 

In order to show the size of the business:

IDC forecasts that worldwide spending on public cloud services and infrastructure will nearly double, to around $500 billion, by 2023.

2. PRIVATE CLOUD

In a private cloud, a cloud computing solution is assigned to an organization. It doesn't matter whether the cloud is managed alone or by a third party, but a private cloud project requires specialized expertise to virtualize a business environment.

In this model Cloud Computing infrastructure assigned to private organisation by service provider over the internet. It supports one enterprise.

There are 2 sub-types of private cloud:

Hosted private clouds, which are offered by a third-party cloud provider, and internal private clouds, which are managed and maintained by an organization internally.

It gives customers more flexibility, however the model is harder to maintain, and cost is higher than public cloud.

 A good analogy I like is that

"A public cloud is like renting an apartment, while a private cloud is like renting a similarly sized house."

3. HYBRID CLOUD

Hybrid cloud model on the other hand is the model where deployments combine one or more public clouds with a private cloud, or with on-premises infrastructure.

In this mixed model, by accessing in-house and public cloud technologies at the same time, users and IT can get the benefits of both worlds. 

As a strategy, more vulnerable and private documents and data may be stored on the private cloud, and information that requires less privacy required may be kept on the public cloud. 

Hybrid cloud provides you high level of control with options for where you can store your data while you are having cheaper scalability with help from the public cloud.

Regarding the migration strategy, it is easier to migrate as you can choose to transition gradually over time 

4. MULTI CLOUD

Multicloud is very similar to hybrid cloud where refers to the use of multiple public clouds concurrently.

This type of cloud environment differ from hybrids, as the presence and usage of many clouds and many cloud providers at the same time (integrated)

A multi-cloud environment can utilize private clouds as well, although it doesn’t have to. Normally, this environment is used because a business has a variety of needs that one single cloud provider doesn’t offer. These requirements / offerings might differ technically, geographically, legally, financially etc. as service may be provided by different vendors.

As number of the players and options are increasing, interoperability among providers and environments is becoming a subject to consider in the technical architecture and business decisions. Will your multi cloud model work together as a unique body? How about migrating a service from one to another?

Therefore at the same time, this model is very powerful and flexible; but this comes with a necessity of designing your landscape well.

As a very quick summary,

Public cloud offers you an easy to manage environment which is not only yours, while private cloud is the one if you want your own cloud to manage but with more cost. If you want to benefit from both of the worlds, you can use the hybrid model and even multi cloud if you want to get services from more than one provider at the same time.

 Questions that should be answered then:

• Which model is better? For my technical landscape, for my business strategy?
• What should be the architecture, what should I change / improve?
• How do I migrate to cloud, which parts, with what timing?

As a part of your business and technology plan, these questions should be answered, and a strategy should be generated.

In the next part of the series, I will write about the use cases technical/business scenarios that is applied with the cloud

RESOURCES

•  Types of cloud computing https://www.redhat.com/en/topics/cloud-computing/public-cloud-vs-private-cloud-and-hybrid-cloud
• What Is a Public Cloud? | Public vs. Private Cloud https://www.cloudflare.com/en-gb/learning/cloud/what-is-a-public-cloud
• Difference Between Public Cloud and Private Cloud https://www.geeksforgeeks.org/difference-between-public-cloud-and-private-cloud/
• Private, Public, Hybrid, or Multi-Cloud: What’s the Difference Between Them? https://blog.storagecraft.com/private-public-hybrid-multi-cloud/