What is hybrid cloud?

A hybrid cloud is, as its name implies, one in which applications are running in a combination of different environments. With one important proviso: that at least one of them is a public cloud. 

The other environments could be private cloud (deployment of cloud-like services over a private network) or traditional on-premise data centres. In certain cases, organisations using hybrid clouds could be drawing on services from two or more public cloud providers.

History of hybrid clouds

When cloud computing first became mainstream, most corporates used some form of private cloud.  There was a sense that moving to a fully public cloud was too radical a step and that businesses wanted some form of continuity with existing providers.

That belief hasn’t gone away: according to a report from Cisco, 82% of IT leaders say that they have adopted the hybrid cloud. Only 8% of organisations are using a single public cloud provider. There’s a clear reluctance to entrust corporate infrastructures wholly to the care of third-party operators, despite the advantages of cloud computing.

How hybrid clouds operate

Within a hybrid cloud environment, organisations can be flexible as to where workloads are initiated and where they are deployed. They could stay running on-premise or in the public cloud, but the real power comes from the ability to move workloads from one environment to another.

It’s this flexibility that is the main impetus for the hybrid model. There could be several reasons for keeping a workload within an on-premise environment rather than in a public cloud … and there could be many reasons for using the public environment too. The ability to break out of a private setup to gain extra capacity is an attractive one for many organisations.

Advantages of hybrid cloud

It’s this flexibility that is so vital to hybrid cloud users.  For example, many companies are reluctant to let a third-party handle customer data or sensitive intellectual property, a decision that could lead them to shun public cloud operators. But under a hybrid model, such data could be stored in-house while using public cloud for all other operations.

In particular, the need to burst into cloud when demand hits a spike (for example, retailers at Christmas) is a big plus. Companies can operate as much as they like in-house but with a useful backup if needed.

There’s also the issue of compliance: since the implementation of GDPR, there are strict controls on how data can be handled. And some businesses, such as those in finance and pharmaceuticals, have additional regulatory requirements.

Finally, a hybrid setup offers some form of redundancy for business continuity. A business can switch operations to the cloud when there’s a particular issue with an in-house data centre but isn’t dependent solely on the cloud provider: even with the tightest service-level agreements, there can be loss of service.

Disadvantages of hybrid cloud

There are many issues to deal with when deploying a hybrid model. There’s the case for managing operations, software needs to be able to work with public cloud and private models – and that’s not an easy issue to solve. Not all applications are suitable to be handled by cloud computing services.

There’s also the pricing issue to consider. One of the big advantages of cloud computing is that a company can limit its capital expenditure by the use of cloud services. By implementing private networks, companies haven’t cut capital costs.

There are also security considerations to bear in mind, particularly in the way that data is being handled. Businesses have to operate under strict guidelines and there’s always the danger that moving between providers and private networks can leave data unprotected. Moving to hybrid cloud is an attractive option for most businesses, but careful consideration should be paid to these disadvantages.

For more resources on cloud computing

You might be interested in reading our explainers “what is public cloud” or “what is multicloud“, as well as our latest feature outlining lessons from 17 years of cloud computing.

In addition, check out our cloud section.