About Hybrid and Multi Cloud

I like to make a joke about how hybrid and multi cloud architectures are usually described, by saying that having both a Tesla and BMW in your garage doesn’t mean that you have a hybrid car, like a Toyota Prius, you have multiple cars. The analogy is simple but I think it helps to distinguish between hybrid or multi cloud.

What I would like to share in this post are my personal opinions about the different types of cloud architectures and what I think is important in the end.? As always everything stated is based on my personal thoughts and understanding.

How the industry understands hybrid and multi cloud

First, the term hybrid means two things blended together to produce another thing.? In the industry, most companies claim that they have a hybrid cloud when what they really have is just two clouds, one private and one public.?

Secondly, in the industry the term? multi is usually applied when the company consumes more than one? public cloud platform or service. There are also some companies that say they have a hybrid cloud when they consume multiple public clouds and also have one private cloud.

In general, the term hybrid cloud usually refers to the combination of a private cloud with one or more public clouds, and the term multi cloud usually refers to the consumption of more than one public cloud .

Analysis of the industry’s understanding

As usual in technology, not only is?there fuzziness in the definitions of certain concepts, but also how they are understood depends on? context. In my view, if we were strict with the meaning of the terms hybrid and multi, a hybrid cloud should be the cloud that is the result of blending two different clouds? and making them behave as a one cloud, as in biology, when two different species are combined to create a new one.? Both clouds should be offered and consumed seamlessly through a common interface and that interface should be implemented over the capabilities offered by the underlying implementations. I also think that the concept of hybrid cloud should not be restricted to only the blending of one private cloud with one public cloud, but it could also be extended beyond two clouds of any nature . The analogy is like a hybrid car that has two engines of different types, but they behave as one engine and the driving experience is (mostly) seamless.?

In the same manner, if we were strict with the term multi cloud, it should be applied when there are multiple clouds of a different nature regardless of whether they are public or private, all of them with their own entity and consumed directly for different purposes. To extend the analogy, a? multi cloud architecture would be like having different vehicles and using different means of transport to go from one place to another. At each stage of the journey the traveler will be fully aware of the vehicle or transport being used.

There are another couple of terms that are used in the industry: distributed cloud and cross-cloud. The first refers to the distribution of the same cloud across? multiple locations. The interface of the cloud is the same regardless of the location.? The main difference with the hybrid case is that the distributed cloud does not blend different cloud implementations, instead it distributes portions of the same cloud into different places. The second term, cross-cloud,? refers to the ability of running workloads across multiple cloud implementations in a seamless way. It can be understood as a particular type of implementation of the hybrid case in which workloads can be moved across the cloud depending on the workload status and its nature.

What I think really matters: the consumer interface

Beyond the terms and the analogies, what I think matters is how the different cloud platforms are consumed and the level of awareness that the consumer has about the implementation that is being used.?

In this regard, a hybrid cloud should be the blending of multiple cloud implementations that are offered transparently through a common interface as another cloud. By contrast, in a multi-cloud architecture, each cloud is consumed directly through its native interface.??

In the case of a multi-cloud architecture, companies should invest in having another interface(or set of interfaces)? to govern and control how the different clouds are offered to the consumers. Ideally this unified control and governance interface should be also offered in a self-serve way to avoid breaking the self-serve? and on-demand nature of the cloud.

Hybrid and Multi Cloud Services

When the hybrid case is explained as above, it can be understood as an abstract layer over the existing? clouds or just merely an API gateway. The idea goes beyond an abstraction layer. Instead, implementing a hybrid cloud service implies having a fully fledged cloud service that under the hood, relies on multiple blended implementations and technologies, but it is a cloud service on its own .A s a such,? it has its own IAM, multi tenancy model, resource management, API model, billing, console, portal...etc. The idea is to build cloud services that blend multiple implementations? from different public cloud platforms and there are some companies and open source projects already doing that.? For example it is possible to build a Hybrid Object Storage that blends different technologies and clouds to offer a new service that is effectively a cloud service on its own. The consumer of that hybrid object storage will not be? aware of the underlying implementations (except upon provisioning time, when depending on the hybrid cloud service implementation, a certain cloud can be required to be selected).

One of the many concerns big enterprises face when consuming cloud services is the vendor lock-in and the coupling with vendor specific APIs, IAM and Resource Management model.? This type of hybrid cloud service can reduce the coupling with specific vendors, bearing in mind that there is always coupling with any interface that is being used. It can also embed specific enterprise controls and policies adapted to particular use cases that are business domain specific (i.e.? object storage for personal data) . But building and maintaining this type of hybrid cloud service can be anything but simple and there are very few in the industry doing that.?

Note: the terms hybrid and multi cloud can be interchanged depending on the point of view taken. For consumers who are not? aware of the underlying implementation they are consuming, the cloud service can be said to be hybrid.? But the providers of those cloud services? can sometimes say that their implementation is multi-cloud, since their internal architecture is aware of the clouds they are using.

Final thoughts?

Beyond the terms hybrid and multi cloud, the important thing is to define the interface and the consumption experience of the different cloud services that are part of the IT architecture. Some companies can decide to have multiple clouds but under a unified control and governance framework with its own interfaces for onboarding, governance and control. Others can decide to isolate themselves from the underlying clouds by having their own cloud services interfaces or restricting the consumption to specific interfaces that are de-facto standards, generally open source. And others can decide to allow direct native consumption without worrying about the vendor lock-in. In any case defining the cloud adoption strategy and specifically how the clouds are going to be interfaced and consumed is key to avoiding a mixture of different approaches difficult to govern and deal with.