The experts disagree on the exact definition of cloud computing, but most concur that it includes the notion of web-based services that are available on-demand from an optimized, and highly scalable, service provider. Despite the technical sound of its characterization, it has not only garnered excitement from technologists but has captured the attention of business leaders around the world.
2009 may long be remembered as the year of the worldwide economic downturn. The impact across many industries, including IT, was devastating. And yet, even then, there were bastions of hope in the midst of all the turmoil. One of the most prominent IT analysts, Gartner, identified cloud computing as the primary source of growth in IT spending, increasing over 20% year-on-year to global revenues of $56B in 2009 and surging to over $130B by 2013!
At the Gartner Emerging Technologies conference in 2008, analysts Daryl Plummer and Thomas Bittman made a bold declaration that: "By 2012, 80 percent of Fortune 1000 companies will pay for some cloud computing service, and 30 percent of them will pay for cloud computing infrastructure". In January 2010, Gartner's prediction became more specific and even more dramatic: "By 2012, 20 percent of businesses will own no IT assets".
Unfortunately the task of defining cloud computing is much more difficult than you might expect. It isn't hard to find an authoritative definition. Virtually anyone with an interest in information technology has one. In fact, that is the root of the problem. Everyone has a different definition of cloud computing. For instance, some definitions that have circulated in the blogosphere include:
The 451 Group: "The cloud is IT as a Service, delivered by IT resources that are independent of location."
Gartner: "Cloud computing is a style of computing where massively scalable IT-related capabilities are provided 'as a service' across the Internet to multiple external customers."
Forrester: "A pool of abstracted, highly scalable, and managed infrastructure capable of hosting end-customer applications and billed by consumption."
Wikipedia: "A style of computing in which dynamically scalable and often virtualized resources are provided as a service over the Internet. Users need not have knowledge of, expertise in, or control over the technology infrastructure 'in the cloud' that supports them."
Out of the over 20 definitions found for cloud computing, the main notions can be assembled into:
"A large pool of easily usable and accessible virtualized resources (such as hardware, development platforms and/or services). These resources can be dynamically reconfigured to adjust to a variable load (scale), allowing also for an optimum resource utilization. This pool of resources is typically exploited by a pay-per-use model in which guarantees are offered by the infrastructure provider by means of customized SLAs."
The most important consideration for any IT manager is not whether a potential solution satisfies the definition of cloud computing but rather whether it adds value to the business. A cloud based solution that does not increase revenue or decrease costs is of little interest. And a completely non-cloud-oriented solution that does unambiguously improve the bottom line should be implemented regardless of the name you use to label it.