Welcome Cloud Computing

Staten describes the concept as "a pool of abstracted, highly-scalable, and managed compute infrastructure capable of hosting end-customer applications and billed by consumption."

Simply put, cloud computing is the next generation model of computing services. It combines the concepts of software being provided as a service, working on the utility computing business model, and running on grid or cluster computing technologies. Cloud computing aims to leverage supercomputing power, which can be measured in tens of trillions of computations per second, to deliver various IT services to users through the Web.

In his report, Staten refers to cloud computing as a service delivery platform, which is built on the same basic fundamentals of traditional hosting or SaaS. The building blocks of cloud computing, he says, that take the concept beyond conventional forms of IT service delivery models are:

• A prescripted and abstracted infrastructure. Fundamental to the cloud computing model is standardization of infrastructure and abstraction layers that allow the fluid placement and movement of services. It starts with a flat implementation of scale-out server hardware that, for some clouds, serves as both compute and storage infrastructure (others are leveraging SAN storage). Their infrastructure enables the cloud and is decided upon solely by the cloud vendor; customers don't get to specify the infrastructure they want -- a major shift from traditional hosting.

• Fully virtualized. Nearly every cloud computing vendor abstracts the hardware with some sort of server virtualization. The majority employ a hypervisor to keep costs low. Some have solutions that span virtual and physical servers via another middleware element, such as a grid engine.

• Equipped with dynamic infrastructure software. Most clouds employ infrastructure software that can easily add, move, or change an application with very little, if any, intervention by cloud provider personnel.

• Pay by use. Most clouds charge by actual use of resources in CPU hours, gigabits (Gbs) consumed, and gigabits per second (Gbps) transferred, rather than by a server or with a monthly fee. Their pricing is compelling.

• Free of long-term contracts. Most cloud vendors let you come and go as you please. The minimum order through XCalibre's FlexiScale cloud, for example, is one hour, with no sign-up fee. This makes clouds an ideal place to prototype a new service, conduct test and development, or run a limited-time campaign without IT commitments.

• Application and OS independent. In most cases, the architectures of clouds support nearly any type of app a customer may want to host as long as it does not need direct access to hardware or specialized hardware elements. Cloud vendors told say there's nothing about their infrastructures that would prevent them from supporting any x86-compatible OS.

• Free of software or hardware installation. You tap into a cloud just as you would any remote server. All you need is a log-in. There's no software or hardware requirement at the customer end nor the need for specialized tools.