Get Past the Confusion Surrounding Hybrid Cloud Computing
In the already overhyped cloud computing market, hybrid cloud computing is emerging as the next big thing. To get past the hype, IT leaders should assess how hybrid cloud computing fits into their road maps, and determine which of its many forms makes sense (and which don't) for their enterprises.
- Hybrid cloud computing is the coordinated use of cloud services across isolation and provider boundaries among public, private and community service providers, or between internal and external cloud services.
- Hybrid cloud services combine multiple services to increase their overall capability or capacity.
- Hybrid cloud computing extends the benefits of cloud computing through improved cost competition, improved internal private cloud utilization, balanced isolation with lower cost, improved resiliency and disaster recovery, etc.
- Hybrid cloud computing's complexity causes challenges — such as guaranteeing service levels across multiple providers, regulatory compliance, appropriate isolation and security — and the need to possibly modify applications to fully leverage a hybrid cloud environment.
- Consider hybrid cloud service compositions when public cloud services do not meet requirements (e.g., for isolation or customization) and private cloud services are not feasible (e.g., for scale).
- Design private cloud services with a hybrid future in mind. Make sure future integration/interoperability is possible.
- Larger enterprises should plan on becoming cloud services brokerages (CSBs) for their enterprise, taking on the integration and orchestration that will be required by hybrid cloud services.
Gartner defines hybrid cloud computing as the coordinated use of cloud services across isolation and provider boundaries among public, private and community service providers, or between internal and external cloud services. Like a cloud computing service, a hybrid cloud computing service is scalable, has elastic IT-enabled capabilities and is delivered as a shared service to customers using Internet technologies. But a hybrid cloud service crosses isolation and provider boundaries so that it can't simply be put in one category of private, public or community cloud service (see "Hype Cycle for Cloud Computing, 2012").
We previously defined hybrid cloud computing as having a focus on composition across internal and external provider boundaries. Our updated definition is more open, recognizing the growing array of sourcing options and the variability of isolation in private, community and public cloud services that could be combined into hybrid forms.
A hybrid cloud service is composed of services that are combined for increased capability beyond what any one service provides (e.g., aggregating services, customizing them or integrating two together) or for additional capacity (aggregation). At the same time, a hybrid cloud service maintains some balanced control of isolation (see "Cloud Services Brokerage Is Dominated by Three Primary Roles").
While the number of combined services could be more than just two, examples of hybrid cloud services are:
- Internal private cloud services combined with external private cloud services: As organizations build internal private clouds, they could also access private cloud services from external providers. This is useful when an enterprise IT organization does not have a capability that a provider has, but still requires isolation, or when a provider can provide isolation even though it is pulling resources for the user out of a shared pool for efficiency purposes. This will also be a common hybrid model for disaster recovery purposes.
- Internal private cloud services plus public cloud services: Internal private clouds require an investment in assets, and maintaining high utilization is important. Enterprise IT can increase utilization of assets by deploying services that could be deployed through public cloud services when the internal capacity is available, but push them to public cloud services when it is not. In addition, a private cloud service can be integrated with a public cloud service to provide richer capability, but customized to enterprises' requirements. An example is data analytics run against a combination of public and private data.
- Internal private cloud services plus community cloud services: Community cloud services will exist for enterprises with similar requirements, but may still need to integrate with private cloud services. Likewise, community cloud services might maintain a capacity pool shared only by the community, and combined with private cloud capacity.
- Community cloud services plus public cloud services: Likewise, community cloud services, especially where asset ownership is shared, would benefit from their ability to use public cloud services as a capacity escape valve. Alternatively, public cloud capability might be customized or integrated with community cloud services for unique community requirements.
Hybrid cloud services can be composed in many ways, varying from relatively static to very dynamic. Three types of composition are:
- Static: A hybrid cloud service can be designed so that services are always used together in the same manner. This is useful for cloud services that bring complementary capabilities or data to the hybrid cloud service.
- Deployment: A hybrid cloud service could be composed each time it is requested. For example, when a virtual machine is requested, one provider or another could be chosen automatically based on deployment policies. Alternatively, at the time a customer asks for a service, the service could do one of two things: (1) choose how to serve the customer, using one of several sources at its disposal (for example, the private cloud might be full, so an alternative might be used); or (2) combine two services instantly to meet the client's need. An example is a compute request that overflows to another service.
- Dynamic: A hybrid cloud service could be changed in a runtime manner based on the service's changing capabilities, data, costs, utilization, scale requirements or problems. A service instance could be moved, or different services could be combined to create a dynamically structured hybrid cloud service.
Managing this composition (especially when it changes at deployment time or dynamically) will often be the responsibility of something filling the role of CSB, which handles aggregation, integration and customization of services (see "Cloud Services Brokerage Is Dominated by Three Primary Roles"). Enterprises that are expanding into hybrid cloud computing from private cloud services are taking on the CSB role (see "Internal CSB Role Is Emerging Within IT Organizations").
Terms like "overdrafting" and "cloudbursting" are often used to describe what hybrid cloud computing will make possible. However, the vast majority of hybrid cloud services will initially be much less dynamic than that. Early hybrid cloud services will likely be more static, engineered compositions (such as integration between an internal private cloud and a public cloud service for certain functionality or data). More deployment compositions will emerge as CSBs evolve (for example, private infrastructure as a service [IaaS] offerings that can leverage external service providers based on policy and utilization). More dynamic compositions will tend to be limited to disaster recovery scenarios, or forklift migrations of services. New applications designed for cloud computing will leverage dynamic composition and scale to provide unique and differentiating value.
There are many examples in the market that are not hybrid cloud services. Each might be valuable for other reasons:
- Catalog: This could be a portal or service catalog in front of several cloud services. While a central starting point for various cloud services is useful, each of the services is, by itself, not hybrid, unless the catalog is combining services behind the scenes in a hybrid manner.
- Cloud service combined with noncloud: Service providers are already offering blended services where hosted workloads can access cloud computing services, and vice versa. These are useful and real-world deployments, but just not hybrid cloud services.
- An application running on a cloud service integrating with another application running on a cloud service: When users of cloud services (in this case, applications) are coordinating and integrating their work it does not mean the cloud services are coordinated or integrated in any way.
- Fixed layers of services: Because a software as a service (SaaS) vendor hosts its software on an IaaS provider's service does not make the SaaS offering a hybrid cloud service (i.e., it's not adding capability or capacity). This is simply a case of a cloud service being used as part of the SaaS provider's implementation supply chain. However, adding a cloud services broker that coordinates the SaaS solution with multiple IaaS providers creates a hybrid cloud service.
Hybrid cloud computing extends the benefits that can be gained by using cloud computing:
- Internal private cloud computing can help maximize asset utilization. Hybrid cloud computing can maximize the value and balance the use of internal assets and external services (e.g., deploying services internally that could also be deployed to public cloud services when the internal capacity is available) while enabling better scalability.
- Cloud computing can help with cost efficiency. Hybrid cloud computing can maximize cost efficiency through competition and automated arbitrage (perhaps not as fluid as a financial market, but more fluid than manually choosing one provider over another).
- Private cloud computing ensures isolation. Hybrid cloud computing allows an enterprise to balance isolation, cost and scaling requirements.
- Cloud computing can enable high availability and resiliency. Hybrid cloud computing can improve resilience and disaster recovery by leveraging multiple providers.
- Cloud computing can introduce new functionality quickly. Hybrid cloud computing makes it easier to leverage new functionality quickly, with better agility.
- Cloud computing ensures a low barrier to entry. Hybrid cloud computing can help an enterprise build-in an exit strategy.
There are also significant challenges associated with hybrid cloud computing. Hybrid cloud computing creates complexity by combining services that have varying levels of isolation, and/or varying levels of customer control. This introduces challenges to achieving necessary performance, security, compliance and overall governance in the combined service. To fully leverage a hybrid cloud environment could require significant application changes.
Hybrid cloud computing is an immature trend that will accelerate over the next five years. A number of factors are driving this trend:
- The explosion of internal private and external public cloud service offerings
- Improved interoperability among providers (including internal private cloud services), tools and technologies that enable CSB capability
- Cloud management platforms that include cloud orchestration
- The need for better resilience and disaster recovery for cloud services
- An increasing demand for agility and scalability
- New workloads that are cloud-aware and can massively scale
- A growing number of workloads with shorter life spans
An enterprise's IT organization should take three important steps toward developing a hybrid cloud computing strategy:
- Design private cloud services for integration and interoperability with external services.
- Investigate emerging CSBs that can create hybrid cloud services.
- Decide if becoming a CSB is the right strategy for enterprise IT.