Cloud computing
Cloud computing is Internet ("cloud") based development and use of computer technology ("computing").It is 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. Cloud computing is an umbrella term used to refer to Internet based development and services. The cloud is a metaphor for the Internet. The key characteristics of cloud computing are: 1. SaaS capabilities 2. Delivery of services in a highly scalable and elastic fashion 3. Usage of Internet technologies and techniques to develop and deliver the services 4. Designing for delivery to external customers Some of the potential benefits of cloud computing include cost savings and the built-in elasticity. These features allow for lower barriers to entry and quick scalability and growth. The concept incorporates infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (SaaS) as well as Web 2.0 and other recent technology trends which have the common theme of reliance on the Internet for satisfying the computing needs of the users. SaaS vendors provide common business applications online that are accessed from a web browser, while the software and data are stored on the servers.
Comparisons Cloud computing is a often 'super confused and with grid computing ("a is form of of distributed a cluster of
computing whereby
virtual
computer'
composed
networked, loosely-coupled computers, acting in concert to perform very large tasks"), utility computing (the "packaging of computing, such as computation and storage, as a metered
service
similar
to
a
traditional public
utility such
as electricity")
and
autonomic
computing ("computer systems capable of self-management"). Indeed many cloud computing deployments as of 2009 depend on grids,
have autonomic characteristics and bill like utilities — but cloud computing can be seen as a natural next step from the grid-utility model. Some successful cloud architectures have little or no centralized infrastructure or billing systems whatsoever, including peer-to-peer networks like Bit Torrent and Skype.
Architecture The majority of cloud computing infrastructure as of 2009 consists of reliable services delivered through data centers and built on servers with different levels of virtualization technologies. The services are accessible anywhere that has access to networking infrastructure. The Cloud appears as a single point of access for all the computing needs of consumers. Commercial offerings need to meet the quality of service requirements of customers and typically offer service level agreements. Open standards are critical to the growth of cloud computing and open source software has provided the foundation for many cloud computing implementations. Characteristics As customers generally do not own the infrastructure, they merely access or rent, they can avoid capital expenditure and consume resources as a service, paying instead for what they use. Many cloud-computing offerings have adopted the utility computing model, which is analogous to how traditional utilities like electricity are consumed, while others are billed on a subscription basis. Sharing "perishable and intangible" computing power among multiple tenants can improve utilization rates, as servers are not left idle, which can reduce costs significantly while increasing the speed of application development. A side effect of this approach is that "computer capacity rises dramatically" as customers do not have to engineer for peak loads. Adoption has been enabled by "increased high-speed bandwidth" which makes it possible to receive the same response times from centralized infrastructure at other sites.
Economics
Cloud computing users can avoid capital expenditure (CapEx) on hardware, software and services, rather paying a provider only for what they use. Consumption is 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. 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 and the services are often covered by service level agreements with financial penalties. According to Nicholas Carr the strategic importance of information technology is diminishing as it becomes standardized and cheaper. He argues that the cloud computing paradigm shift is similar to the displacement of electricity generators by electricity grids early in the 20th century. Companies Providers including Amazon, Google and Yahoo exemplify the use of cloud computing. It is being adopted by individual users through large enterprises including General Electric, L’Oreal, and Procter & Gamble.
History The Cloud is a term with a long history in telephony, which has in the past decade, been adopted as a metaphor for internet based services, with a common depiction in network diagrams as a cloud outline. The underlying concept 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 which date back to the 1960s. The term cloud had already come into commercial use in the early 1990s to refer to large ATM networks. By the turn of the 21st century, the term "cloud computing" had started to appear, although most of the focus at this time was on Software as a service (SaaS). In 1999, Salesforce.com was established by Marc Benioff, Parker Harris, and his fellows. They applied many technologies of consumer web sites like Google and Yahoo! to business applications. They also provided the concept of "On demand" and "SaaS" with their real business and successful customers. The key for SaaS is being customizable by customer alone or with a small amount of help. Flexibility and speed for application development have been drastically welcomed and accepted by business users. IBM extended these concepts in 2001, as detailed in the Autonomic Computing Manifesto which described advanced automation techniques such as self-monitoring, selfhealing, 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.com played a key role in the development of cloud computing by modernizing their data centres after the dot-com bubble and, having found that the new cloud architecture resulted in significant internal efficiency improvements, providing access to their systems by way of Amazon Web Services in 2002 on a utility computing basis. 2007 saw increased activity, with Google, IBM, and a number of universities embarking on a large scale cloud computing research project, around the time the term started gaining
popularity in the mainstream press. It was a hot topic by mid-2008 and numerous cloud computing events had been scheduled. In August 2008, Gartner Research observed that "organizations are switching from companyowned hardware and software assets to per-use service-based models" and 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." Cloud computing is at an early stage, with a motley crew of providers large and small delivering a slew of cloud-based services, from full-blown applications to storage services to spam filtering. Utility-style infrastructure providers are part of the mix, but so are SaaS (software as a service) . Today, for the most part, IT must plug into cloud-based services individually, but cloud computing aggregators and integrators are already emerging. 1. SaaS This type of cloud computing delivers a single application through the browser to thousands of customers using a multitenant architecture. On the customer side, it means no upfront investment in servers or software licensing; on the provider side, with just one app to maintain, costs are low compared to conventional hosting. SaaS is common for HR apps and has even worked its way up to ERP. Example: SaaS "desktop" applications, such as Google Apps and Zoho Office. 2. Utility computing The idea is not new, but this form of cloud computing is getting new life from Amazon.com, Sun, IBM, and others who now offer storage and virtual servers that IT can access on demand. Early enterprise adopters mainly use utility computing for supplemental, non-mission-critical needs, but one day, they may replace parts of the datacenter. Other providers offer solutions that help IT create virtual datacenters from commodity servers, such as 3Tera's AppLogic and Cohesive Flexible Technologies' Elastic Server on Demand. Liquid Computing's LiquidQ offers
similar capabilities, enabling IT to stitch together memory, I/O, storage, and computational capacity as a virtualized resource pool available over the network. 3. Web services in the cloud Closely related to SaaS, Web service providers offer APIs that enable developers to exploit functionality over the Internet, rather than delivering full-blown applications. They range from providers offering discrete business services -- such as Strike Iron and Xignite -- to the full range of APIs offered by Google Maps, ADP payroll processing, the U.S. Postal Service, Bloomberg, and even conventional credit card processing services. 4. Platform as a service Another SaaS variation, this form of cloud computing delivers development environments as a service. You build your own applications that run on the provider's infrastructure and are delivered to your users via the Internet from the provider's servers.. Prime examples include Salesforce.com’s, Force.com, Coghead and the new Google App Engine. For extremely lightweight development, cloud-based mash up platforms abound, such asYahoo Pipes or Dapper.net. 5. MSP (managed service providers) One of the oldest forms of cloud computing, a managed service is basically an application exposed to IT rather than to end-users, such as a virus scanning service for e-mail or an application monitoring. Managed security services delivered by SecureWorks, IBM, and Verizon fall into this category, as do such cloud-based anti-spam services. Other offerings include desktop management services. 6. Service commerce platforms A hybrid of SaaS and MSP, this cloud computing service offers a service hub that users interact with. They're most common in trading environments, such as expense management systems
that allow users to order travel or secretarial services from a common platform that then coordinates the service delivery and pricing within the specifications set by the user. Think of it as an automated service bureau. 7. Internet integration The integration of cloud-based services is in its early days. OpSource, which mainly concerns itself with serving SaaS providers, recently introduced the OpSource Services Bus, which employs in-the-cloud integration technology. SaaS provider Workday recently acquired another player in this space, CapeClear, an ESB (enterprise service bus) provider that was edging toward b-to-b integration. Cloud computing is an umbrella term used to refer to Internet based development and services. The cloud is a metaphor for the Internet. A number of characteristics define cloud data, applications services and infrastructure: Remotely hosted – Services or data are hosted on someone else’s infrastructure. Ubiquitous - Services or data are available from anywhere. Commodified – The result is a utility computing model similar to traditional that of traditional utilities, like gas and electricity. You pay for what you would like. Cloud Storage Over time many big Internet based companies have come to realize that only a small amount of their data storage capacity is being used. This has led to the renting out of space and the storage of information on remote servers or "clouds". Information is then temporarily cached on desktop computers, mobile phones or other internet-linked devices. Data Cloud Along with services the cloud will host data. There has been some discussion of this being a potentially useful notion possibly aligned with the Semantic Web, though it could result in data becoming undifferentiated.
Opportunities and Challenges The use of the cloud provides a number of opportunities: It enables services to be used without any understanding of their infrastructure. Cloud computing works using economies of scale. It lowers the outlay expense for start up companies, as they would no longer need to buy their own software or servers. Cost would be by on-demand pricing. Vendors and service providers claim costs by establishing an ongoing revenue stream. Data and services are stored remotely but accessible from ‘anywhere’. In parallel there has been significant backlash against cloud computing: Use of cloud computing means dependence on others and that could possibly limit flexibility and innovation. The ‘others’ are likely become the bigger Internet companies like Google and IBM who may monopolise the market. Some argue that this use of supercomputers is a return to the time of mainframe computing that the PC was a reaction against. Security could prove to be a big issue. It is still unclear how safe outsourced data is and when using these services ownership of data is not always clear. There are also issues relating to policy and access. If your data is stored abroad whose FOI policy do you adhere to? What happens if the remote server goes down? How will you then access files? There have been cases of users being locked out of accounts and loosing all access to data. The Future Over the next five years, IDC expects spending on IT cloud services to grow almost threefold, reaching $42 billion by 2012 and accounting for 9% of revenues in five key market segments. More importantly, spending on cloud computing will accelerate throughout the forecast period, capturing 25% of IT spending growth in 2012 and nearly a third of growth the following year. DC expects the cloud adoption trend to be amplified by the current financial crisis. The cloud model offers a much cheaper way for businesses to acquire and use IT – in an economic downturn, the appeal of that cost advantage will be greatly magnified. This advantage is
especially important for small and medium businesses, a sector that will be key target in any plan for recovery.
The implication for IT suppliers is very clear: the next three years, as IT cloud services expand from Early Adopters to the Early Majority, is the critical time to develop strong cloud offerings, and play a leadership role in bringing customers, your own organization and your partner ecosystem “across the chasm”.
https://secure.hosting.com/pdf/eBooks/2009CloudComputingTrendsReport.pdf