Hybrid Cloud

Alessandro Mirani

Cloud infrastructures are generally described using three macro categories: public, private and hybrid. A public cloud is defined as a cloud that is accessible via the public Internet. The goal for those who offer a public Cloud service is, ususally, to acquire as many customers as possible. The largest cloud services such as Amazon AWS, Microsoft Azure, and Google’s GCP fall into this category.

Private cloud, on the other hand, refers to a cloud infrastructure to which only members of a company, for example, or small group have exclusive access. A common use case for private cloud are companies using servers on which users share files that can be accessed via VPN or other dedicated connection. Those using a private cloud aim, usually, for exclusivity of access to computational resources rather than saturation of said resources.

The hybrid cloud (Hybrid Cloud) is a mix of the two solutions. In this article we will look at how, and why, using a hybrid solution might be your best entry route to the Cloud world.

What is a Hybrid Cloud

Once you understand the difference between Public and Private Cloud, the Hybrid Cloud becomes almost intuitive. A Hybrid Cloud service can easily be defined as one that employs resources accessible via the public Internet and resources accessible only via a private connection. In this model, applications operate by relying on a combination of the two types of infrastructure for both computational work and data storage.

The benefits of a hybrid model

Not all companies are immediately ready or willing to move their entire IT structure from an on-prem or private cloud system to a public cloud. This makes a Hybrid Cloud a good gradual transition solution.

In addition, not all companies are neophytes to cloud infrastructure. The more a company has invested in building a private cloud infrastructure, the less likely it is that the services offered by a public cloud will be cost-effective. Although the pay-per-use (pay-per-use) model is attractive to most consumers, those who have an infrastructure already in place, with which they are familiar, and over which they have total control, have several reasons to cautiously consider a radical shift to the public cloud. An operating cost model (OpEx) tends to be less cost-effective than capital investment (CapEx) as time passes and the infrastructure scales. The hybrid cloud, in this case, allows you to choose which infrastructure to invest in and which to keep as operating expenses, maximizing return on investment (ROI).

As with costs, control over information security in a private cloud model is undoubtedly greater. However, just because a company manages critical information does not mean that all information circulating in the IT apparatus is critical. On the other hand, the availability of public cloud infrastructure is not guaranteed in all regions of the world, and for legal reasons you may have to manage data in a region where the public infrastructure does not offer service.

The hybrid cloud model allows us to keep information and infrastructure close together over which we need to apply more control. Not only from a security standpoint, but also from an information retrieval speed standpoint, a hybrid model allows for more control. If by chance you are not satisfied with the minimum latency a public cloud service can offer in a particular region, you can always integrate with your own private data center, for example, by creating a hybrid facility.

Finally, you may not want to take the risk of entrusting all your most critical facilities to one provider. By adopting a configuration that includes multiple vendors, referred to as a “multicloud,” or configured among multiple private clouds, you can spread the risk more widely and ensure greater resilience in the event of an incident.

The risks of a hybrid model

A hybrid approach to the cloud seems like the ideal solution for everyone. However, it is not so obvious for at least 3 reasons:

  • Compatibility: the old saying goes “easier said than done”; as convenient as it is to move to a cloud infrastructure, there is no guarantee that the apps and services you are looking to migrate to will be compatible with the environments you move to. Not only the apps you migrate but also the underlying infrastructure that remains private may need to communicate and/or interact with the public side. None of this is a given just as it is not a given that the adaptations needed to smooth out these bumps are cost-effective.
  • Maintenance costs: the more your infrastructure scales, especially in multi-cloud, the more expensive and difficult it can be to have visibility into all components; a dispersed infrastructure requires more maintenance cost. While you save money in managing individual physical components, you will have to invest in management operations.
  • SLAs (Service Level Agreements): The guaranteed level of service varies from vendor to vendor and from one service plan to another. Not only can it happen that the level of service (performance and incident resilience guarantees) is not adequate for your needs, but it can happen that the vendor decides to change the price range from one year to the next, exposing you to operational and financial uncertainties.

Carefully weighing these risks against the benefits will enable you to make a more informed cloud migration decision, preparing you for the next step: implementation.

How is hybrid cloud implemented?

We can distinguish three main methodologies of hybrid cloud adoption:

  • Repositioning: Lift and Shift, that is, lift and shift your resources or app from the private cloud to the public cloud without substantial changes.
  • Refactoring: Lift, tinker and shift. Some changes to update the app and improve it to enable it to be in the public and private cloud at the same time are applied.
  • Refactoring: Where refactoring and repositioning are not cost-effective, or possible, applications and infrastructure must be engineered from scratch to operate in the hybrid model.

Major public cloud vendors already offer several services that enable the implementation of hybrid structures; GCP’s Anthos, AWS Outposts, and Azure Arc are some of the services these companies offer to initiate an easy transition and robust integration between public and private clouds.


Cloud technologies are expanding the range of services offered and data collected by enterprises, but cloud does not always and necessarily mean relying on third-party infrastructure. Hybrid cloud technologies offer the opportunity to get the best of “both worlds.” Choosing the right mix of public and private cloud can enable you to reduce risk and cost while maintaining security and performance at the desired levels.

Compatibility, development/maintenance costs, and performance differences are the issues not to be underestimated when defining your hybrid migration strategy.

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