Which Cloud Computing solution to choose? Public Vs Private Cloud

Damian Szewczyk Damian Szewczyk

An excellent alternative to the classic server infrastructure is cloud computing. Cloud computing is a service consisting in the provision of computing power offered by external providers, which is made available on demand, and the adjustment of parameters is solely up to the customers. One of cloud computing’s additional advantages is the pay-as-you-go model. We pay for the resources that we actually need and use.

If you want to move to the cloud or start your business in the cloud from the very beginning, you need to decide which type of cloud will fit your needs best. You have three options to choose from: public cloud, private cloud and hybrid cloud. Today I will focus on the first two. I will define them and describe their characteristics, use in specific cases and how they differ from each other. Hybrid infrastructure will be the subject of the next article.

Public Cloud

It is the most popular cloud type. Its servers and resources belong to external cloud providers. The biggest cloud providers are companies such as Amazon with Amazon Web Services cloud, Google with Google Cloud and Microsoft with Azure.

In a public cloud, only the service provider has access to the infrastructure. Consequently, all responsibility for the hardware lies with the public cloud provider. Customers, regardless of the size of their company, use the same services as other cloud users. You can be a small company from Birmingham or a large enterprise from Amsterdam, it doesn’t matter. Regardless of where and who you are, when you use a public cloud, you use the same resources as other businesses.

The cloud can be managed via a web browser or API. As customers, we are not entirely exempt from responsibilities such as backing up or architecting the solution according to best practices. Cloud users are bound by the principle of shared responsibility. I will explain this principle is in one of the next posts soon.

Examples of basic public cloud services are e.g. computing facilities (EC2), storage (S3), databases (RDS) or Lambda type services enabling the transition to Serverless. Examples of companies that conduct most of their operations in the cloud are Netflix and Spotify. These are international companies that offer uninterrupted access to their products, even in crisis situations, thanks to the public cloud.

Private Cloud

Private cloud has also other names such as internal, corporate or business cloud. As the name suggests, its main feature is privacy.

Private cloud does not mean the same thing for everyone and can take different forms. The common characteristic of all solutions called private cloud is that they provide the basic functionality of a cloud, i.e. instant provisioning of infrastructure (at the click of a button), scaling and consumption-based billing. 

The differences lie in where the private cloud is located, i.e. within the enterprise using it or at an external provider, as well as in the level of separation, i.e. at the level of logistics and physical hardware. 

Each of these solutions has its pros and cons, and the most common drivers for building a private cloud are legal requirements or company policies. This type of cloud is most often chosen by entities that need to be separated from other users, e.g. by government organisations, financial institutions and other public business entities.

Differences between a Public and Private Cloud

Private clouds are chosen by those who put formal requirements first or are simply afraid of change. This is not always justified however because private clouds are often less secure than public ones. This is a factor that outweighs even elements such as flexibility and scalability. Other reasons for choosing a private cloud can be short response times, e.g. when operating machines in factories, or the utilisation of existing hardware resources.

The downside of choosing a private environment is the cost. In order to run a private cloud, the one-off costs are considerably higher than in the case of a public cloud. This is due to the need to purchase the infrastructure and the platform and to later implement it. In the case of the public cloud, the costs are lower.

From a financial point of view, the public cloud wins in the first battle with the private cloud. Without the need to purchase and install hardware, cloud usage costs are reduced. However, with larger installations and building infrastructure, you may find that a private cloud is just as cost-effective as a public cloud. It all depends on the amount of resources you use and the variability of your demand for them. 

One of the advantages of the public cloud is that you can buy only as much computing power as you will need at any given time. There are also flexible resource management options, if your needs change over time. This mirrors the flexibility and scalability of resources in a public cloud.

In a private cloud, when available physical resources become saturated, you need to buy extra hardware and dedicate work to expand. Building additional infrastructure takes time, and the whole process does not happen in a matter of minutes as is the case with a public cloud. With reference to the previous difference, we must bear in mind the different fees for services. In a public cloud, fees are charged for actual resource consumption, meaning you only pay for the time that you use the services. This is counted in hours or even minutes. Thanks to this we gain full billing transparency. In a private cloud the rules are not as clear. Although we can charge for the resources of end users, such as marketing or IT departments, we still have to maintain the entire infrastructure, even if we do not use

Which Cloud type is right for You?

The choice here depends primarily on the legal or technological requirements of your business. It is easy to conclude that if you represent a financial or public institution, the private cloud seems to be the best choice. The same applies if you have a lot of hardware resources to make use of. The public cloud will be a good solution when your business needs include fast start-up or resource consumption billing.

However, there are some exceptions where your needs will point to one of these solutions or a hybrid cloud, and what industry you are in will matter less.

What to watch out for when making a decision?

Try to overcome your fear of the unknown, the important issues when choosing the cloud type are internal factors, the specification of the applications you will use. Use them as your guiding light. Also, don’t get persuaded by hardware and software vendors who say “… run your own cloud, it’s really that easy”. Take my word for it, it’s not 😉

Choosing the right infrastructure can prove to be a daunting task, especially considering that everyone has a different opinion on existing solutions and will arguably whisper it in your ear. In my opinion, it is important to be guided by both knowledge and experience.

In the next article I will talk about a hybrid cloud, which is a combination of a public and private cloud. I invite you to join the discussion and ask questions. I have daily contact with various server solutions, from standard hosting, through dedicated servers, to cloud computing. I will be happy to point you in the right direction in order to make your future decisions easier and better for you.


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