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Above the Clouds: A Berkeley View of Cloud Computing

February 12, 2009

Hoping to emulate the influence of the report “The Landscape of Parallel Computing Research: A View From Berkeley” from the University of California Berkeley Electrical Engineering and Computer Sciences (EECS) Department’s Parallel Computing Laboratory (Par Lab), a group of a dozen faculty and grad students in the EECS Reliable Adaptive Distributed Systems Laboratory (RAD Lab) spent six months brainstorming about the impact and future directions of “cloud computing.” David Patterson, who has a joint appointment as a researcher in Lawrence Berkeley National Laboratory’s Computational Research Division, was one of the leaders of both projects.

Read an HPCwire interview with “Above the Clouds” co-authors David Patterson and Armando Fox here.

The resulting report, “Above the Clouds: A Berkeley View of Cloud Computing,” is now available at That page includes the white paper, executive overview, PowerPoint slides, video discussion, and blog.

“Cloud computing” has been a popular buzzword for the past few years, yet to many it remains a fuzzy concept. Here is how “Above the Clouds” defines it:

Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS), so we use that term. The datacenter hardware and software is what we will call a Cloud.

When a Cloud is made available in a pay-as-you-go manner to the public, we call it a Public Cloud; the service being sold is Utility Computing. Current examples of public Utility Computing include AmazonWeb Services, Google AppEngine, and Microsoft Azure. We use the term Private Cloud to refer to internal datacenters of a business or other organization that are not made available to the public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not normally include Private Clouds.

The authors of “Above the Clouds” believe cloud computing has the potential to transform a large part of the information technology (IT) industry. “Developers with innovative ideas for new interactive Internet services no longer require the large capital outlays in hardware to deploy their service or the human expense to operate it,” they write. “They need not be concerned about over-provisioning for a service whose popularity does not meet their predictions, thus wasting costly resources, or under-provisioning for one that becomes wildly popular, thus missing potential customers and revenue.”

Moreover, companies with large computing tasks can get their results quicker than ever, since using 1000 cloud servers for one hour costs no more than using one in-house server for 1000 hours. “This elasticity of resources, without paying a premium for large scale, is unprecedented in the history of IT,” the report states. It goes on to define terms, presents an economic model that quantifies the key buy vs. pay-as-you-go decision, offers a spectrum to classify Cloud Computing providers, and lists the top 10 obstacles and opportunities to the growth of Cloud Computing.

Patterson describes the Web posting of the report and background materials and the ensuing online discussion as “an experiment in alternative publishing in this modern world.” He notes that the first “Berkeley View” report, which was disseminated the same way, was likely read by more people than any refereed paper he co-authored in the last decade. “Above the Clouds” will eventually be submitted to a traditional refereed journal or magazine, but it will probably take one or two years to be published in that form.