What is a Hybrid Cloud?
Clouds are made up of resources (in the form of Servers and/or Services) that are delivered to one or more consumers without the consumer being required to have knowledge of the specific underlying infrastructure. What makes this a Hybrid Cloud? A Hybrid Cloud has the ability to cross one or more boundaries based on either a set of conditions or manual intervention. What might be a condition? Maybe a datacenter has run out of capacity and still needs to meet additional demands on its web servers. In this example, by leveraging a Hybrid Cloud model, the datacenter could automatically have additional webservers brought online by a third party service provider to provide additional capacity. This means that the data center's cloud extended accross its normal boudndaries and leveraged resources from the service provider's cloud. This is a simple scenario, more complex scenarios are certainly possible and are leveraged by some companies already.
What makes this an attractive model for businesses?
Businesses need to be able to meet demands on a real-time basis, yet they don't want to pay for excess compute capacity that will sit idle. This was the inital catalyst for what became the call for server consolidation (this is what led to VMware's explosive growth and the reason it became so popular in data centers). Now that many larger businesses have consolidated, they continue to look at ways of adding more business applications however they don't want to buy resources based on peak usage. Enter the Hybrid Cloud Model, providing the benefits of having critical data locally (meeting laws and regulatory requirements) while having services and dynamic expansion/contraction abilities beyond the capacity of the local/private cloud (or traditional IT Datacenter)
Illustrated In the Series of Images Below is a Typical Use Case for a Hybrid Cloud:
Because Hybrid Clouds can provide a greater depth and flexibility versus simply an internal cloud (or an external cloud for that matter) businesses are beginning to look at what cost savings can be brought on by leveraging this model. Companies like VMware and Microsoft have seen this and have begun to take Amazon's lead in public cloud (external cloud) offerings and attempt to make private and hybrid clouds accessible to medium and large businesses. Hybrid Clouds will become a core tool that businesses leverage over the next 5 to 7 years. The problem will be in the management of these highly abstracted, complex, fast moving environments as complex workloads cross cloud boundaries. Once Hybrid Clouds have built appropriate momentum, they will be the norm for many years to come.