Cloud Computing Essay Example for Free

Cloud Computing Essay * Integrated development environment as a service (IDEaaS) In the business model using software as a service, users are provided access to application software and databases. The cloud providers manage the infrastructure and platforms on which the applications run. SaaS is sometimes referred to as â€Å"on-demand software† and is usually priced on a pay-per-use basis. SaaS providers generally price applications using a subscription fee. Proponents claim that the SaaS allows a business the potential to reduce IT operational costs by outsourcing hardware and software maintenance and support to the cloud provider. This enables the business to reallocate IT operations costs away from hardware/software spending and personnel expenses, towards meeting other IT goals. In addition, with applications hosted centrally, updates can be released without the need for users to install new software. One drawback of SaaS is that the users data are stored on the cloud provider’s server. As a result, there could be unauthorized access to the data. End users access cloud-based applications through a web browser or a light-weight desktop or mobile app while the business software and users data are stored on servers at a remote location. Proponents claim that cloud computing allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and enables IT to more rapidly adjust resources to meet fluctuating and unpredictable business demand.[2][3] Cloud computing relies on sharing of resources to achieve coherence and economies of scale similar to a utility (like the electricity grid) over a network.[4] | This article may contain original research. Please improve it by verifying the claims made and adding references. Statements consisting only of original research may be removed. (January 2013)| The origin of the term cloud computing is obscure, but it appears to derive from the practice of using drawings of stylized clouds to denote networks in diagrams of computing and communications systems. The word cloud is used as a metaphor for the Internet, based on the standardized use of a cloud-like shape to denote a network on telephony schematics and later to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents. The cloud symbol was used to represent the Internet as early as 1994.[5][6] The underlying concept of cloud computing dates back to the 1950s, when large-scale mainframe became available in academia and corporations, accessible via thin clients / terminalcomputers. Because it was costly to buy a mainframe, it became im portant to find ways to get the greatest return on the investment in them, allowing multiple users to share both the physical access to the computer from multiple terminals as well as to share the CPU time, eliminating periods of inactivity, which became known in the industry as time-sharing.[7] In the 1990s, telecommunications companies, who previously offered primarily dedicated point-to-point data circuits, began offering virtual private network (VPN) services with comparable quality of service but at a much lower cost. By switching traffic to balance utilization as they saw fit, they were able to utilize their overall network bandwidth more effectively. The cloud symbol was used to denote the demarcation point between that which was the responsibility of the provider and that which was the responsibility of the users. Cloud computing extends this boundary to cover servers as well as the network infrastructure.[8] As computers became more prevalent, scientists and technologists explored ways to make large-scale computing power available to more users through time sharing, experimenting with algorithms to provide the optimal use of the infrastructure, platform and applications with prioritized access to the CPU and efficiency for the end users.[9] John McCarthy opined in t he 1960s that computation may someday be organized as a public utility. Almost all the modern-day characteristics of cloud computing (elastic provision, provided as a utility, online, illusion of infinite supply), the comparison to the electricity industry and the use of public, private, government, and community forms, were thoroughly explored in Douglas Parkhills 1966 book, The Challenge of the Computer Utility. Other scholars have shown that cloud computings roots go all the way back to the 1950s when scientist Herb Grosch (the author of Groschs law) postulated that the entire world would operate on dumb terminals powered by about 15 large data centers.[10] Due to the expense of these powerful computers, many corporations and other entities could avail themselves of computing capability through time sharing and several organizations, such as GEs GEISCO, IBM subsidiary The Service Bureau Corporation (SBC, founded in 1957), Tymshare (founded in 1966), National CSS (founded in 1967 and bought by Dun Bradstreet in 1979), Dial Data (bought by Tymshare in 1968), and Bolt, Beranek and Newman (BBN) marketed time sharing as a commercial venture. The development of the Internet from being document centric via semantic data towards more and more services was described as Dynamic Web.[11] This contribution focused in particular in the need for better meta-data able to describe not only implementation details but also conceptual details of model-based applications. The ubiquitous availability of high-capacity networks, low-cost computers and storage devices as well as the widespread adoption of hardware virtualization, service-oriented architecture,autonomic, and utility computing have led to a tremendous growth in cloud computing.[12][13][14] After the dot-com bubble, Amazon played a key role in the development of cloud computing by modernizing their data centers, 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 (teams small enough to be fed with two pizzas) could add new features faster and more easily, Amazon initiated a new product development effort to provide cloud computing to external customers, and launched Amazon Web Service (AWS) on a utility computing basis in 2006.[15][16] In early 2008, Eucalyptus became the first open-source, AWS API-compatible platform for deploying private clouds. In early 2008, OpenNebula, enhanced in the RESERVOIR European Commission-funded project, became the first open-source software for deploying private and hybrid clouds, and for the federation of clouds.[17] In the same year, efforts were focused on providing quality of service guarantees (as required by real-time interactive applications) to cloud-based infrastructures, in the framework of the IRMOS European Commission-funded project, resulting to a real-time cloud environment.[18] 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[19] and observed that organizations are switching from company-owned hardware and software assets to per-use service-based models so that the projected shift to computing will result in dramatic growth in IT products in some areas and significant reductions in other areas.[20] On March 1, 2011, IBM announced the Smarter Computing framework to support Smarter Planet.[21] Among the various components of the Smarter Computing foundation, cloud computing is a critical piece. [edit] Similar systems and concepts Cloud computing shares characteristics with: * Autonomic computing — Computer systems capable of self-management.[22] * Client–server model — Client–server computing refers broadly to any distributed application that distinguishes between service providers (servers) and service requesters (clients).[23] * Grid computing — A form of distributed and parallel 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. * Mainframe computer — Powerful computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics, police and secret intelligence services, enterprise resource planning, and financial transaction processing.[24] * 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.[25][26] * Peer-to-peer — Distributed architecture without the need for central coordination, with participants being at the same time both suppliers and consumers of resources (in contrast to the traditional client–server model). * Cloud gaming Also known as on-demand gaming, this is a way of delivering games to computers. The gaming data will be stored in the providers server, so that gaming will be independent of client computers used to play the game. [edit] Characteristics Cloud computing exhibits the following key characteristics: * Agility improves with users ability to re-provision technological infrastructure resources. * Application programming interface (API) accessibility to software that enables machines to interact with cloud software in the same way the user interface facilitates interaction between humans and computers. Cloud computing systems typically use REST-based APIs. * Cost is claimed to be reduced and in a public cloud delivery model capital expenditure is converted to operational expenditure.[27] This is purported to lower barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and fewer IT skills are required for implementation (in-house).[28] The e-FISCAL projects state of the art repository[29] contains several articles looking into cost aspects in more detail, most of them concluding that costs savings de pend on the type of activities supported and the type of infrastructure available in-house. * Device and location independence[30] enable users to access systems using a web browser regardless of their location or what device they are using (e.g., PC, mobile phone). As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet, users can connect from anywhere.[28] * Virtualization technology allows servers and storage devices to be shared and utilization be increased. Applications can be easily migrated from one physical server to another. * Multitenancy enables sharing of resources and costs across a large pool of users thus allowing for: * Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.) * Peak-load capacity increases (users need not engineer for highest possible load-levels) * Utilisation and efficiency improvements for systems that are often only 10–20% utilised.[15] * Reliability is improved if multiple redundant sites are used, which makes well-designed cloud computing su itable for business continuity and disaster recovery.[31] * Scalability and elasticity via dynamic (on-demand) provisioning of resources on a fine-grained, self-service basis near real-time,[32] without users having to engineer for peak loads.[33][34] * Performance is monitored, and consistent and loosely coupled architectures are constructed using web services as the system interface.[28] * Security could improve due to centralization of data, increased security-focused resources, etc., but concerns can persist about loss of control over certain sensitive data, and the lack of security for stored kernels.[35] Security is often as good as or better than other traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford.[36] However, the complexity of security is greatly increased when data is distributed over a wider area or greater number of devices and in multi-tenant systems that are being shared by unrelated users. In addition, user access to security audit logs may be difficult or impossible. Private cloud installations are in part motivated by users desire to retain control over the infrastructure and avoid losing control of information security. * Maintenance of cloud computing applications is easier, because they do not need to be installed on each users computer and can be accessed from different places. The National Institute of Standards and Technologys definition of cloud computing identifies five essential characteristics: On-demand self-service. A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider. Broad network access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations). Resource pooling. The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. Rapid elasticity. Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time. Measured service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. —National Institute of Standards and Technology[4] On-demand self-service See also: Self-service provisioning for cloud computing services and Service catalogs for cloud computing services On-demand self-service allows users to obtain, configure and deploy cloud services themselves using cloud service catalogues, without requiring the assistance of IT.[37][38] This feature is listed by the National Institute of Standards and Technology (NIST) as a characteristic of cloud computing.[4] The self-service requirement of cloud computing prompts infrastructure vendors to create cloud computing templates, which are obtained from cloud service catalogues. Manufacturers of such templates or blueprints include Hewlett-Packard (HP), which names its templates as HP Cloud Maps[39] RightScale[40] and Red Hat, which names its templates CloudForms.[41] The templates contain predefined configurations used by consumers to set up cloud services. The templates or blueprints provide the technical information necessary to build ready-to-use clouds.[40] Each template includes specific configuration details for different cloud infrastructures, with information about servers for specific tasks such as hosting applications, databases, websites and so on.[40] The templates also include predefined Web service, the operating system, the database, security configurations and load balancing.[41] Cloud consumers use cloud templates to move applications between clouds through a self-service portal. The predefined blueprints define all that an application requires to run in different environments. For example, a template could define how the same application could be deployed in cloud platforms based on Amazon Web Service, VMware or Red Hat.[42] The user organization benefits from cloud templates because the technical aspects of cloud configurations reside in the templates, letting users to deploy cloud services with a push of a button.[43][44] Cloud templates can also be used by developers to create a catalog of cloud services.[45] [edit] Ser vice models Cloud computing providers offer their services according to three fundamental models:[4][46] infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) where IaaS is the most basic and each higher model abstracts from the details of the lower models. In 2012 network as a service (NaaS) and communication as a service (CaaS) were officially included by ITU (International Telecommunication Union) as part of the basic cloud computing models, recognized service categories of a telecommunication-centric cloud ecosystem.[47] Infrastructure as a service (IaaS) See also: Category:Cloud infrastructure In the most basic cloud-service model, providers of IaaS offer computers physical or (more often) virtual machines and other resources. (A hypervisor, such as Xen or KVM, runs the virtual machines as guests.) Pools of hypervisors within the cloud operational support-system can support large numbers of virtual machines and the ability to scale services up and down according to customers varying requirements. IaaS clouds often offer additional resources such as images in a virtual-machine image-library, raw (block) and file-based storage, firewalls, load balancers, IP addresses, virtual local area networks (VLANs), and software bundles.[48] IaaS-cloud providers supply these resources on-demand from their large pools installed indata centers. For wide-area connectivity, customers can use either the Internet or carrier clouds (dedicated virtual private networks). To deploy their applications, cloud users install operating-system images and their application software on the cloud infrastructure. In this model, the cloud user patches and maintains the operating systems and the application software. Cloud providers typically bill IaaS services on a utility computing basis: cost reflects the amount of resources allocated and consumed. Examples of IaaS providers include Amazon CloudFormation, Amazon EC2, Windows Azure Virtual Machines, DynDNS, Google Compute Engine, HP Cloud, iland, Joyent,Rackspace Cloud, ReadySpace Cloud Services, and Terremark. [edit] Platform as a service (PaaS)