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Cloud computing--A Primer

Wednesday, October 28, 2009

by Biodun Iginla, BBC News Technology Analyst

Cloud computing is the provision of dynamically scalable and often virtualised resources as a service over the Internet on a utility basis.[1][2] From a conceptual point of view, cloud computing refers to a paradigm shift in computing whereby computing resource and underlying technical infrastructure are abstracted away from the user. Users need not have knowledge of, expertise in, or control over the technology infrastructure in the "cloud" that supports them.[3] Cloud computing services often provide common business applications online that are accessed from a web browser, while the software and data are stored on the servers.
The term cloud is used as a metaphor for the Internet, based on how the Internet is depicted in computer network diagrams and is an abstraction of the underlying infrastructure it conceals.[4]
A technical definition is "a computing capability that provides an abstraction between the computing resource and its underlying technical architecture (e.g., servers, storage, networks), enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction."[5] This definition states that clouds have five essential characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.[5]

Cloud computing can be confused with:

Grid computing—"a form of distributed computing whereby a 'super and virtual computer' is composed of a cluster of networked, loosely coupled computers acting in concert to perform very large tasks";
Utility computing—the "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility, such as electricity";[6] and
Autonomic computing—"computer systems capable of self-management".[7]

Indeed, many cloud computing deployments as of 2009[update] depend on grids, have autonomic characteristics, and bill like utilities—but cloud computing tends to expand what is provided by grids and utilities.[8] Some successful cloud architectures have little or no centralized infrastructure or billing systems whatsoever, including peer-to-peer networks such as BitTorrent and Skype, and volunteer computing such as SETI@home.[9][10]
Furthermore, many analysts are keen to stress the evolutionary, incremental pathway between grid technology and cloud computing, tracing roots back to application service providers (ASPs) in the 1990s and the parallels to SaaS, often referred to as applications on the cloud.[11] Some believe the true difference between these terms is marketing and branding; that the technology evolution was incremental and the marketing evolution discrete.[12]
Characteristics Cloud computing customers do not generally own the physical infrastructure serving as host to the software platform in question. Instead, they avoid capital expenditure by renting usage from a third-party provider. They consume resources as a service and pay only for resources that they use. Many cloud-computing offerings employ the utility computing model, which is analogous to how traditional utility services (such as electricity) are consumed, while others bill on a subscription basis. Sharing "perishable and intangible" computing power among multiple tenants can improve utilization rates, as servers are not unnecessarily left idle (which can reduce costs significantly while increasing the speed of application development). A side effect of this approach is that overall computer usage rises dramatically, as customers do not have to engineer for peak load limits.[13] Additionally, "increased high-speed bandwidth" makes it possible to receive the same response times from centralized infrastructure at other sites.
Economics Diagram showing economics of cloud computing versus traditional IT, including capital expenditure (CapEx) and operational expenditure (OpEx) Cloud computing users can avoid capital expenditure (CapEx) on hardware, software, and services when they pay a provider only for what they use. Consumption is usually billed on a utility (e.g. resources consumed, like electricity) or subscription (e.g. time based, like a newspaper) basis with little or no upfront cost. A few cloud providers are now beginning to offer the service for a flat monthly fee as opposed to on a utility billing basis. Other benefits of this time sharing style approach are low barriers to entry, shared infrastructure and costs, low management overhead, and immediate access to a broad range of applications. Users can generally terminate the contract at any time (thereby avoiding return on investment risk and uncertainty) and the services are often covered by service level agreements (SLAs) with financial penalties.[14][15]
According to Nicholas Carr, the strategic importance of information technology is diminishing as it becomes standardized and less expensive. He argues that the cloud computing paradigm shift is similar to the displacement of electricity generators by electricity grids early in the 20th century.[16]
Although companies might be able to save on upfront capital expenditures, they might not save much and might actually pay more for operating expenses. In situations where the capital expense would be relatively small, or where the organization has more flexibility in their capital budget than their operating budget, the cloud model might not make great fiscal sense. Other factors impacting the scale of any potential cost savings include the efficiency of a company’s data center as compared to the cloud vendor’s, the company's existing operating costs, the level of adoption of cloud computing, and the type of functionality being hosted in the cloud.[17][18]
Architecture The majority of cloud computing infrastructure, as of 2009[update], consists of reliable services delivered through data centers and built on servers with different levels of virtualization technologies. The services are accessible anywhere that provides access to networking infrastructure. Clouds often appear as single points of access for all consumers' computing needs. Commercial offerings are generally expected to meet quality of service (QoS) requirements of customers and typically offer SLAs.[19] Open standards are critical to the growth of cloud computing, and open source software has provided the foundation for many cloud computing implementations.[20]

History

The Cloud is a term that borrows from telephony. Up to the 1990s, data circuits (including those that carried Internet traffic) were hard-wired between destinations. Subsequently, long-haul telephone companies began offering Virtual Private Network (VPN) service for data communications. Telephone companies were able to offer VPN-based services with the same guaranteed bandwidth as fixed circuits at a lower cost because they could switch traffic to balance utilization as they saw fit, thus utilizing their overall network bandwidth more effectively. As a result of this arrangement, it was impossible to determine in advance precisely which paths the traffic would be routed over. The term "telecom cloud" was used to describe this type of networking, and cloud computing is conceptually somewhat similar.
The underlying concept of cloud computing dates back to 1960, when John McCarthy opined that "computation may someday be organized as a public utility"; indeed it shares characteristics with service bureaus that date back to the 1960s. In 1997, the first academic definition was provided by Ramnath K. Chellappa who called it a computing paradigm where the boundaries of computing will be determined by economic rationale rather than technical limits.[21] The term cloud had already come into commercial use in the early 1990s to refer to large Asynchronous Transfer Mode (ATM) networks.[22] By the turn of the 21st century, the term "cloud computing" began to appear more widely,[23] although most of the focus at that time was limited to SaaS.
In 1999, Salesforce.com was established by Marc Benioff, Parker Harris, and their associates. They applied many technologies developed by companies such as Google and Yahoo! to business applications. They also provided the concepts of "on demand" and SaaS with their real business and successful customers. The key for SaaS is that it is customizable by customers with limited technical support required. Business users have enthusiastically welcomed the resulting flexibility and speed.
In the early 2000s, Microsoft extended the concept of SaaS through the development of web services. IBM detailed these concepts in 2001 in the Autonomic Computing Manifesto, which described advanced automation techniques such as self-monitoring, self-healing, self-configuring, and self-optimizing in the management of complex IT systems with heterogeneous storage, servers, applications, networks, security mechanisms, and other system elements that can be virtualized across an enterprise.
Amazon played a key role in the development of cloud computing by modernizing their data centers after the dot-com bubble which, like most computer networks, were using as little as 10% of their capacity at any one time just to leave room for occasional spikes. Having found that the new cloud architecture resulted in significant internal efficiency improvements whereby, small, fast-moving "two-pizza teams" could add new features faster and easier, Amazon started providing access to their systems through Amazon Web Services on a utility computing basis in 2005.[24]
In 2007, Google, IBM, and a number of universities embarked on a large scale cloud computing research project.[25] By mid-2008, Gartner saw an opportunity for cloud computing "to shape the relationship among consumers of IT services, those who use IT services and those who sell them",[26] and observed that "[o]rganisations are switching from company-owned hardware and software assets to per-use service-based models" so that the "projected shift to cloud computing ... will result in dramatic growth in IT products in some areas and in significant reductions in other areas."[27]
Political issues The Cloud spans many borders and "may be the ultimate form of globalization."[28] As such, it becomes subject to complex geopolitical issues, and providers are pressed to satisfy myriad regulatory environments in order to deliver service to a global market. This dates back to the early days of the Internet, when libertarian thinkers felt that "cyberspace was a distinct place calling for laws and legal institutions of its own"[28].
Despite efforts (such as US-EU Safe Harbor) to harmonize the legal environment, as of 2009[update], providers such as Amazon Web Services cater to major markets (typically the United States and the European Union) by deploying local infrastructure and allowing customers to select "availability zones."[29] Nonetheless, concerns persist about security and privacy from individual through governmental levels (e.g., the USA PATRIOT Act, the use of national security letters, and the Electronic Communications Privacy Act's Stored Communications Act.
Legal issues In March 2007, Dell applied to trademark the term "cloud computing" (U.S. Trademark 77,139,082) in the United States. The "Notice of Allowance" the company received in July 2008 was cancelled in August, resulting in a formal rejection of the trademark application less than a week later.
In September 2008, the United States Patent and Trademark Office (USPTO) issued a "Notice of Allowance" to CGactive LLC (U.S. Trademark 77,355,287) for "CloudOS". As defined under this notice, a cloud operating system is a generic operating system that "manage[s] the relationship between software inside the computer and on the Web", such as Microsoft Azure [30].
In November 2007, the Free Software Foundation released the Affero General Public License, a version of GPLv3 intended to close a perceived legal loophole associated with Free software designed to be run over a network, particularly SaaS. An application service provider is required to release any changes they make to Affero GPL open source code.[citation needed]
Control issues The founder and president of the Free Software Foundation Richard Stallman has warned people that cloud computing will force people to buy into locked, proprietary systems that will cost more and more over time.[31] Posted by BiodunIginla at 10:17 PM Labels: bbc biodun iginla, bbc news, cloud computing 0 comments: