Cheat Sheet

Hybrid Cloud For Dummies

From Hybrid Cloud For Dummies by Judith Hurwitz, Marcia Kaufman, Fern Halper, Dan Kirsch

A company deploys a hybrid cloud when it uses public and private cloud services in combination with its internal data center(s). Hybrid cloud usage assumes that at least two of these deployment models need to integrate in some way, such as to share data. Understand the reality of the hybrid cloud by knowing some basic background information — including the elements of cloud computing, hybrid cloud delivery models, and the foundational elements of the hybrid cloud.

Cloud Computing Elements

A hybrid computing model enables an organization to leverage both public and private computing services to create a more flexible and cost-effective computing utility:

  • The public cloud is a set of hardware, networking, storage, service, and interfaces owned and operated by a third party for use by other companies or individuals.

  • A private cloud is a set of hardware, networking, storage, service, and interfaces owned and operated by an organization for the use of its employees, partners, and customers.

  • In a hybrid cloud environment, an organization combines services and data from a variety of models to create a unified, automated, and well-managed computing environment.

Whether your cloud is public, private, or hybrid, you'll need a cloud provider that provides elasticity, scalability, provisioning, standardization, and billed usage. Elasticity is important because it means that you are able to use a service for a long or short period of time based on need. You can add more services from a self-service portal rather than wait for IT to do the heavy lifting for you. Increasingly, as companies begin to understand that they will use a combination of different platforms to meet different business needs, the hybrid cloud will become the foundation for computing. The advent of the hybrid cloud will also help redefine the purpose and use of the traditional data center as well.

One of the fundamental differences between cloud computing and traditional computing is the way a cloud is designed to manage resources. Whereas the data center is designed to manage applications, the cloud is intended to manage a pool of resources. A pool of resources is precisely what it sounds like — a set of shared, configured services that are independent of physical location.

For example, suppose you are a cloud provider. You do not want customers to have to select one server or one storage system; rather, the customer is abstracted from that idea. Instead, the customer simply says I need some more storage, and those storage resources are pooled together from various physical systems to create a set of resources. Customers never know which storage system they are accessing. To make resource pooling work, it's important that each element that is pooled be written with service-oriented constructs in mind. This means that each resource is written as an independent service without dependencies and with well-defined interfaces.

Exploring Hybrid Cloud Delivery Models

Four delivery models are used to create a hybrid cloud environment. Some of these models will be used as stand-alone capabilities, whereas others will be intertwined to meet a business goal:

  • The Infrastructure as a Service Delivery Model: Infrastructure as a Service (IaaS) is the virtual delivery of computing resources in the form of hardware, networking, and storage services. It may also include the delivery of operating systems and virtualization technology to manage the resources. It can be the most cost-effective model because it offers customers basic computing or storage capability in an elastic model. In an elastic model, it's possible to use some storage, for example, and to stop using and paying for that storage when the task is completed. These infrastructure services can be based on a public service such as or RackSpace, or they can be designed as an internal utility for use inside an organization. The fact that a vendor or an IT organization can optimize these services by customizing both the operating system and the underlying services to support a specific type workload (such as email) makes it easy to support a large number of users or customers with very low cost.

  • The Platform as a Service Delivery Model: The Platform as a Service (PaaS) delivery model includes infrastructure services combined with development tools and middleware that is built into the environment. It, therefore, provides a way for development organizations to build and deploy their own applications in a more flexible manner. In a hybrid environment, PaaS can be combined with on-premises development approaches. PaaS is dependent on combining with IaaS. PaaS supports the ability to abstract complexity away from the developers so that there is consistency and predictability in the development and deployment of software.

  • The Software as a Service Delivery Model: The Software as a Service (SaaS) delivery model includes both IaaS and PaaS. It's the development of packaged software services that are built in and live in a cloud environment. These services need to be combined with data and other service elements from other clouds and from data centers.

  • Business Process as a Service Delivery Model: Business Process as a Service (BPaaS) is a set of services that works in combination with IaaS, PaaS, and SaaS, as well as application services that run in data centers. Basically, BPaaS is a codification of processes needed to execute a business policy. BPaaS can be anything from a simple credit-checking service to a complex business process for managing end-to-end commerce transactions. It's imperative for companies to be able to leverage public, private, and data center services to implement business policies and automate workflow.

Hybrid Cloud Foundational Elements

The hybrid cloud requires foundational elements to make a hybrid model work in the real world. Although there are many issues and technical considerations when using the hybrid cloud, understanding the following elements is particularly important:

  • Virtualization services: It's not surprising that many companies have taken the time to streamline their data centers through technologies such as server virtualization. In essence, virtualization decouples the software from the hardware. In decoupling, the software is put into a separate container so that it's isolated from the underlying operating system. With the use of virtualization, applications can be managed on servers in a more efficient manner.

  • Service orientation: Organizations that have invested in creating business services that are encapsulated, and therefore decoupled from underlying business applications, are well positioned for hybrid computing. These services include well-defined interfaces so they can be integrated with other services to create value. These services, whether a simple business process or a codified way to manage a set of data elements, can provide the way to integrate services from different origins into a hybrid cloud environment.

  • Service management: Automation, optimization, and workload management are keys to making a hybrid cloud environment operational. Therefore, companies that are looking at the hybrid cloud need to focus on how a combination of services can be brought together to create a well-functioning system.

These foundational elements form the underlying infrastructure that supports a company's ability to integrate data, applications, and processes across multiple environments. For the hybrid cloud to be operationally effective, standardized interfaces are needed so that services built from a variety of environments can be linked together when needed. All these cloud services must include a method of metering based on use. Clearly, public cloud service companies will meter and bill you based on what you use. In internal clouds, the IT organization needs to keep track of usage to make sure resources are used appropriately across the organization.

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