A hybrid cloud is an integrated cloud service utilising both private and public clouds to perform distinct functions within the same organisation. All cloud computing services should offer certain efficiencies to differing degrees but public cloud services are likely to be more cost efficient and scalable than private clouds. Therefore, an organisation can maximise their efficiencies by employing public cloud services for all non-sensitive operations, only relying on a private cloud where they require it and ensuring that all of their platforms are seamlessly integrated.
Hybrid cloud models can be implemented in a number of ways:
- Separate cloud providers team up to provide both private and public services as an integrated service
- Individual cloud providers offer a complete hybrid package
- Organisations who manage their private clouds themselves sign up to a public cloud service which they then integrate into their infrastructure
A hybrid cloud configuration, such as hybrid hosting, can offer its users the following features:
- Scalability; whilst private clouds do offer a certain level of scalability depending on their configurations (whether they are hosted internally or externally for example), public cloud services will offer scalability with fewer boundaries because resource is pulled from the larger cloud infrastructure. By moving as many non-sensitive functions as possible to the public cloud it allows an organisation to benefit from public cloud scalability whilst reducing the demands on a private cloud.
- Cost efficiencies; again public clouds are likely to offer more significant economies of scale (such as centralised management), and so greater cost efficiencies, than private clouds. Hybrid clouds therefore allow organisations to access these savings for as many business functions as possible whilst still keeping sensitive operations secure.
- Security; the private cloud element of the hybrid cloud model not only provides the security where it is needed for sensitive operations but can also satisfy regulatory requirements for data handling and storage where it is applicable
- Flexibility; the availability of both secure resource and scalable cost effective public resource can provide organisations with more opportunities to explore different operational avenues.
HYBRID CLOUD DEFINITION
Hybrid cloud is a cloud computing environment which uses a mix of on-premises, private cloud and third-party, public cloud services with orchestration between the two platforms. By allowing workloads to move between private and public clouds as computing needs and costs change, hybrid cloud gives businesses greater flexibility and more data deployment options.
For example, an enterprise can deploy an on-premises private cloud to host sensitive or critical workloads, but use a third-party public cloud provider, such as Google Compute Engine, to host less-critical resources, such as test and development workloads. To hold customer-facing archival and backup data, a hybrid cloud could also use Amazon Simple Storage Service (Amazon S3). A software layer, such as Eucalyptus, can facilitate private cloud connections to public clouds, such as Amazon Web Services (AWS).
Hybrid cloud is particularly valuable for dynamic or highly changeable workloads. For example, a transactional order entry system that experiences significant demand spikes around the holiday season is a good hybrid cloud candidate. The application could run in private cloud, but use cloud bursting to access additional computing resources from a public cloud when computing demands spike. To connect private and public cloud resources, this model requires a hybrid cloud environment.
Another hybrid cloud use case is big data processing. A company, for example, could use hybrid cloud storage to retain its accumulated business, sales, test and other data, and then run analytical queries in the public cloud, which can scale to support demanding distributed computing tasks.
Public cloud's flexibility and scalability eliminates the need for a company to make massive capital expenditures to accommodate short-term spikes in demand. The public cloud provider supplies compute resources, and the company only pays for the resources it consumes.
Despite its benefits, hybrid cloud can present technical, business and management challenges. Private cloud workloads must access and interact with public cloud providers, so hybrid cloud requires API compatibility and solid network connectivity.
For the public cloud piece of hybrid cloud, there are potential connectivity issues, SLA breaches and other possible public cloud service disruptions. To mitigate these risks, organizations can architect hybrid workloads that interoperate with multiple public cloud providers. However, this can complicate workload design and testing. In some cases, workloads slated for hybrid cloud must be redesigned to address the specific providers' APIs.