Hybrid cloud: issues and success factors in the cohabitation of proprietary architectures

A hybrid cloud is a cloud infrastructure composed of a private cloud and a public cloud. Unlike a public cloud where resources are shared between several clients, a private cloud groups together all the servers and resources dedicated to a company. These privatised infrastructures can be outsourced as well as on-premise.

The hybrid cloud is therefore the technical solution aimed at linking these two distinct cloud infrastructures with the objective of benefiting from the advantages of both approaches.

Since 2016, the hybrid cloud has been in full development (1)*, even if companies initially seem to favour the private cloud (the first link in the hybrid cloud). By 2022, 45% of companies in the industrial sector plan to integrate the hybrid cloud, compared with 19% in 2019 (2)*.

Although several studies tend to show that the hybrid cloud seems to be the best cloud solution to date (3, 4)*, several obstacles can be observed for a massive integration of this technology.

Benefits and success factors

It is obvious that flexibility is the main asset of a hybrid cloud. The ability to interconnect a private cloud and a public cloud means that data, applications and services can be easily transferred from one to the other and vice versa as required. Thus, a company with such a hybrid architecture is able to decide where to deploy workloads according to their criticity or availability (secure vs. open to the outside world / production environment vs. test environment / persistence in time vs. limited duration).

The elasticity of a cloud – whatever its type – and therefore its flexibility are also major criteria to be taken into account when evaluating a hybrid infrastructure. In the event of a rapid need for additional resources, it is easy with this type of cloud to call on the public part to extend the capacities (computing, storage, servers) of the private part. Thus, for a company with a hybrid cloud and an immediate occasional need, it is easier to set up a calculation or data analysis cluster, or a data warehouse (Hadoop cluster for example) in a public cloud, than to deploy such a solution in its own private infrastructure, which will necessarily be longer, more technical, and therefore more expensive.

Finally, the distinction between the public and private parts of a hybrid cloud ensures a high level of security for both data – what is sensitive is stored in the private part of the infrastructure – and applications. A company with a hybrid infrastructure remains the master and decision-maker of its IS, and is able to decide what is public and what is private. Based on the previous example of the data cluster in the public part of a hybrid cloud, it makes sense, for example, to keep the operation and the results of the data analysis in the private part.

So while applications which are easy to move to the cloud have already been moved, the majority of applications are often maintained on-premises due to issues such as data severity, sovereignty, compliance, cost or interdependency with other systems. The hybrid cloud thus provides a different answer for companies seeking to achieve their transformation goals in a complex IT operating environment.

Issues and obstacles

Although the benefits of such a hybrid structure are obvious, it should be noted that implementing a hybrid cloud is a highly complex task and requires a great deal of expertise, making it a difficult project to implement. Complexity and integration difficulties are the main reasons for delays and even failures in hybrid cloud deployments.

Setting up a private cloud requires qualified resources capable of administering solutions implementing multiple servers dedicated to computing, storage and network communication. Among these applications we can cite OpenStack or Apache CloudStack, which allow the creation of a true private cloud in one’s own IS. Given the complexity of such a task, it is possible to use a private cloud managed by a third party provider, or to use the proprietary solutions AWS Outposts, Microsoft Azure Stack or Google Anthos, which simplify the implementation of a hybrid cloud, based on managed hardware in an approach aimed at reducing complexity and risk.

The interconnection between the private and public parts can also be a source of technical and organisational complexity. One of the major challenges in setting up a hybrid architecture is to avoid turning this private/public link into a gas factory that is difficult to maintain and manage. It is also important to be vigilant about the exchanges between the two clouds, and for example, it is not uncommon to see a public cloud provider change its APIs, which in turn leads to changes in the private part. As the junction between the public and private clouds is the entry point to the heart of a company’s information system, it is necessary to ensure that all accesses are correctly secured and encrypted, which makes the implementation of such a system even more complex.

The cloud promises to unleash business growth potential while minimising costs. However, to avoid wasting resources and overspending, applications need to be optimised for the cloud by placing them in the right environment and maintaining visibility into their performance and resource consumption. It is therefore necessary for an organisation to have an orchestration component that can select the best place to deploy resources in the hybrid cloud based on security, load, cost, availability or traffic criteria.

Because of the complexity of such a structure, both in its implementation and in its administration and monitoring, it is almost mandatory for a company wishing to integrate the hybrid cloud to have sufficient human, time and therefore financial resources.

This is confirmed by the emergence on the market of private solutions from public cloud operators, which despite their different technologies and functions, target precisely the difficulties and obstacles of hybrid cloud architectures through the :

• Simplified management and architecture of the hybrid cloud, by having the same technologies on and off site,
• Reduced risk, cost and staffing requirements,
• Accelerate and simplify application development by enabling developers to be more efficient by sharing the same services and resources on and off site

However, these solutions of facto reduce the control that a company has over its IS and consequently the interest of the hybrid cloud.

* : 1 - Hybrid Cloud usage in France, CXP Group

* : 2 - Hybrid cloud study, Nutanix 2019

* : 3 - The study published by Nutanix reports that 91% of business IT managers believe that the hybrid cloud is the ideal solution today to achieve the benefits of both types of cloud

* : 4 - The analysis firm 451 Research even states that from 2019 onwards, 69% of companies will use this hybrid infrastructure.