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Public, private, hybrid cloud: how to choose your cloud environment ?

Migrating your company’s IT infrastructure to the cloud means that you need to understand what is at stake for your company and make the right technical choices. When it comes to the cloud, several solutions or environments are possible. Public, private, hybrid cloud… However, there is nothing to prevent you from choosing several solutions depending on your needs and designing a hybrid cloud or a multi-cloud architecture.

This way, your company can rely on various cloud environments and expect the whole to work as one, seamlessly, thanks to APIs, VPNs and WANs. In practice, which cloud environment(s) should you choose for your needs?


What are the different cloud models ?


Public cloud

Public cloud refers to an outsourced cloud, managed by a cloud provider, and shared with other organizations. In this case, your company rents dedicated space, one or more virtual machines (VMs), web apps, functions, within a server or cluster of physical servers occupied by multiple companies. These servers can be in the same datacenter or spread out in several locations around the world.


Private cloud

In the case of a private cloud, the servers used are for the exclusive use of your company. They can be your own servers, in your own datacenter, or servers hosted by a cloud provider. In the case of an on-prem private cloud, the company is responsible for all maintenance, as with on-prem servers. On the other hand, when the private cloud is outsourced, the provider can take care of these services, as for a public cloud.


Hybrid and multi-cloud

The hybrid cloud simply implies that the company uses both cloud environments (public and/or private) and on-prem servers. It combines computing resources, storage and services from these different environments.
However, to speak of hybridization, all the environments must be interconnected, creating a unified cloud.

The term multi-cloud is used when the company operates several cloud environments, but no local servers. In this case, the company uses different CSPs, such as AWS, Azure and GCP, for redundancy purposes, for example, or to avoid putting all its eggs in one basket.


Benefits of the hybrid cloud: flexibility and economy

Opting for a hybrid cloud is generally aimed at accelerating the digital transformation of a company. By combining cloud and on prem solutions, a company can modernize its IT environment. Moreover, by rationalizing investments, good governance of the hybrid cloud generates savings.

In addition, by re-engineering its infrastructure with new technologies that are designed to scale, an organization can end or drastically reduce siloed infrastructure management with a focus on microservices and API integrations. The result is greater agility and a significant competitive advantage.

In an enterprise, the hybrid cloud allows you to take advantage of the strengths of each cloud and on-premises solutions to leverage an optimal resource pool. This way, it manages performance issues, security (by differentiating protocols by application and by platform), geographical constraints…

By creating an integrated solution, the different cloud environments manage their data together and share them easily. Workloads can be migrated quickly and automatically between different clouds and on-premises servers. Similarly, a hybrid cloud makes it easier and faster to deploy new applications or features. It is also used to manage business peaks, especially when there is a seasonality to the business.

What are the advantages and limitations of public and private clouds ? How to distribute your needs in the right cloud environments ?


Advantages and disadvantages of the public cloud

The main advantages of the public cloud, such as Azure, AWS or GCP, are that it offers great flexibility and is generally less expensive than private cloud or on prem solutions.

Its flexibility allows it to evolve on demand towards more or less resources in storage or performance.
It also allows its customers to benefit from maintenance and a certain level of security provided by the provider.

As an outsourced solution, the public cloud requires less or no hardware investment (capex). It is also particularly reliable, relying on multiple datacenters to ensure continuous availability of services.

However, it offers less control over the security of the physical infrastructure. In addition, the public cloud requires a high degree of cost control because the resources are very easy to deploy but quickly generate additional costs that must be managed. Thus, in case of need of more important resources, in particular in computing power, the price can climb quickly.


Advantages and disadvantages of the private cloud

A private cloud, whether internalized or outsourced, means that the company has a customized infrastructure.

It can therefore set up a security policy that potentially best suits its needs. Most public clouds offer virtual firewall services of the same brand as physical firewalls (Fortinet’s FortiCloud, etc.), so the quality of the solutions offered is equivalent. On the other hand, the adaptability of the private cloud makes it the ideal cloud model for managing sensitive data.

A private cloud also provides better cost control. Because, if the initial investments are higher than for a public cloud (especially in the case of an internalized private cloud), the company can manage as it sees fit its storage resources and performance, avoiding unexpected price increases.

On the other hand, it is up to the company to manage the maintenance of its private cloud. However, it can outsource them to a service provider specialized in infrastructure managed services. It also becomes fully responsible for the safety and security of the compliance of its infrastructure.

In addition, a private cloud is less flexible. This is because the company has its own server or server cluster. It is therefore more difficult to reduce or increase the available resources.


Hybrid Cloud Disadvantages: Design and Management

By multiplying the environments, the IT infrastructure of a company offers hackers and malicious bots a larger surface of attack, more possible points of entry. Fortunately, it is possible to rely on Castelis services via the Cloudflare solutions especially to secure the entire IT infrastructure. In this respect, Cloudflare can reduce the attack surface by up to 90%.

In addition, a practicable hybrid cloud implies that the cloud infrastructure must be well designed upstream in order to be able to migrate applications to suitable, already well-configured environments. In this way, we can drastically reduce refactoring and modernization of applications.

Special attention must also be paid to security rules and compliance. This is because when data flows and workloads are deployed, all steps must be secure and compliant with standards and regulations.

Finally, managing a hybrid cloud often means running both virtual machines and containerized architectures. The skills expected of technical teams are therefore expanding as the company multiplies the number of platforms.


The best cloud providers for businesses

Here are the public cloud solutions we recommend, whether you need a public cloud only, or you are creating or evolving a hybrid cloud.


Microsoft Azure

Microsoft Azure is a hybrid cloud platform. It includes products and services for building and managing applications. It’s secure from end to end and complies with regulations. No investment is required-you pay only for the resources you use. The solution is integrated with Microsoft Dynamics 365, a set of interconnected applications. The solution has been proven so well that Castelis is a Gold Partner of Microsoft Azure.


AWS or Amazon Web Services

AWS is the cloud computing solution offered by Amazon. It exists in IaaS, PaaS and SaaS modes. It has several advantages including its agility and modularity.


GCP or Google Cloud Platform

GCP also brings together various cloud services. It allows you to benefit from a global infrastructure where the security of encrypted data is a major concern. Support is responsive. GCP is renowned for an availability and uptime close to 100%.

At Castelis, we are agnostic. We work with the 3 major public clouds in France, tested, proven and therefore approved. Our teams are certified multi-cloud and can integrate other solutions according to your needs.


Need a cloud solution for your IT infrastructure ? Simply contact our cloud experts to discuss your project !