Cloud computing
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Cloud computing refers to computing resources and services that are provided over the internet. It allows users to access applications and store data on remote servers rather than local devices. There are different types of cloud services including Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). Cloud computing can be deployed using public, private, community, or hybrid models depending on factors like security needs and resource sharing requirements. Many universities and organizations are conducting research on cloud computing technologies.
Cloud computing
- 1. Misha Ali Page 1 5/5/2014 ASSIGNMENT # 1 CLOUD COMPUTING
- 2. loud computing in general can be portrayed as a synonym for distributed computing over a network, with the ability to run a program or application on many connected computers at the same time. It specifically refers to a computing hardware machine or group of computing hardware machines commonly referred as a server connected through a communication network such as the Internet, an intranet, a local area network (LAN) or wide area network (WAN) and individual users or user who have permission to access the server can use the server's processing power for their individual computing needs like to run an application, store data or any other computing need. Therefore, instead of using a personal computer every-time to run the application, the individual can now run the application from anywhere in the world, as the server provides the processing power to the application and the server is also connected to a network via internet or other connection platforms to be accessed from anywhere 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 that a traditional user interface (e.g., a computer desktop) facilitates interaction between humans and computers. Cloud computing systems typically use Representational State Transfer (REST)-based APIs. Cost: cloud providers claim that computing costs reduce. A public-cloud delivery model converts capital expenditure to operational expenditure. This purportedly lowers 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). The e-FISCAL project's state-of-the-art repository contains several articles looking into cost aspects in more detail, most of them concluding that costs C
- 3. savings depend on the type of activities supported and the type of infrastructure available in-house. Device and location independence enable users to access systems using a web browser regardless of their location or what device they use (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. Virtualization technology allows sharing of servers and storage devices and increased utilization. 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) utilization and efficiency improvements for systems that are often only 10–20% utilized. Reliability improves with the use of multiple redundant sites, which makes well-designed cloud computing suitable for business continuity and disaster recovery. Scalability and elasticity via dynamic ("on-demand") provisioning of resources on a fine- grained, self-service basis in near real-time (Note, the VM startup time varies by VM type, location, os and cloud providers), without users having to engineer for peak loads. Performance is monitored, and consistent and loosely coupled architectures are constructed using web services as the system interface. Security can 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. 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 to tackle. However, the complexity of security is greatly increased when data is distributed over a wider area or over a greater number of devices, as well as in multi-tenant systems 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 user's computer and can be accessed from different places.
- 4. Services: Software as a Service (SaaS): Most known and first service, major service given as part of cloud computing service In this case the application itself is provided by the service provider, typically via web browser Gartner estimates that SaaS revenue will be more than double its 2010 members by 2015 and reach a projected $ 21.3 bn Examples User mail: Gmail, Hotmail User pictures: Picasa , Flicker Enterprise: WebEx , OfficeLive Platform as a Service (PaaS): PaaS – Platform as a Service Hosted Application environment for developing and deploying cloud based applications Examples: Google’s App engine Amazon EC2 Microsoft Azure Infrastructure as a Service (IaaS): Iaas – Service provider offers capacity for rent basically hosted data centers and servers An evaluation of Web sites and server hosting services which provided services and virtual private servers. Examples: Amazon EC2 Rackspace AT&T – hosting and storage
- 5. Advantages: 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. Cloud computing is the broader concept of converged infrastructure and shared services. The cloud also focuses on maximizing the effectiveness of the shared resources. Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users. For example, a cloud computer facility that serves European users during European business hours with a specific application (e.g., email) may reallocate the same resources to serve North American users during North America's business hours with a different application (e.g., a web server). Cloud Computing should maximize the use of computing power thus reducing environmental damage as well since less power, air conditioning, rackspace, etc. are required for a variety of functions. With cloud computing, multiple users can access a single server to retrieve and update their data without purchasing licenses for different applications.
- 6. Cloud Computing Deployment Models An agency can deploy cloud computing in several different ways depending upon many factors, such as: Where the cloud services are hosted Security requirements Desire to share cloud services The ability to manage some or all of the services Customization capabilities There are four common deployment models for cloud services loosely determined by who has access to the cloud services: Public Cloud, Private Cloud, Community Cloud, and Hybrid Cloud. Public Cloud: A "public" cloud infrastructure is available to the general public and is owned by a third party cloud service provider (CSP). In a public cloud, an agency dynamically provisions computing resources over the Internet from a CSP who shares its resources with other organizations. Similar to that of an electric utility billing system, the CSP bills the agency for its share of resources. This can be the most cost effective deployment model for agencies as it gives them the flexibility to procure only the computing resources they need and delivers all services with consistent availability, resiliency, security, and manageability. Nevertheless, to benefit from a public cloud, an agency must accept the reduced control and monitoring over the CSP’s governance and security.
- 7. Private Cloud: A "private" cloud infrastructure is operated solely for a single organization or agency: the CSP dedicates specific cloud services to that agency and no other clients. The agency specifies, architects, and controls a pool of computing resources that the CSP delivers as a standardized set of services. A common reason for agencies to procure private clouds is their ability to enforce their own data security standards and controls. An agency will typically host private cloud on-premises, connect to it through private network links, and only share its resources within the agency. Because resources are not pooled across multiple unaffiliated organizations, an agency will pay for all of the cloud's capacity. Nevertheless, the agency's Chief Information Officer (CIO) can provide these resources as services on-demand to organizations and programs within the agency and charge them accordingly. Community Cloud A "community" cloud infrastructure is procured jointly by several agencies or programs that share specific needs such as security, compliance, or jurisdiction considerations. The agencies or CSP may manage the community cloud and may keep it on-premises or off-premises. When agencies have a common set of requirements and customers, a community cloud enables them to combine assets and share computing resources, data, and capabilities. By eliminating the duplication of similar systems, agencies can save money and allocate their scarce resources
- 8. more efficiently. Procuring a community cloud is also a way that an agency can advance the Federal IT Shared Service Strategy. Hybrid Cloud: A "hybrid" cloud comprises two or more clouds (private, community, or public) with a mix of both internally and externally hosted services. Agencies will likely not limit themselves to one cloud deployment but will rather incorporate different and overlapping cloud services to meet their unique requirements. Hybrid deployment models are complex and require careful planning to execute and manage especially when communication between two different cloud deployments is necessary.
- 9. Research Many universities, vendors, Institutes and government organizations are investing in research around the topic of cloud computing: In October 2007, the Academic Cloud Computing Initiative (ACCI) was announced as a multi-university project designed to enhance students' technical knowledge to address the challenges of cloud computing. In April 2009, UC Santa Barbara released the first open source platform-as-a- service, AppScale, which is capable of running Google App Engine applications at scale on a multitude of infrastructures. In April 2009, the St Andrews Cloud Computing Co-laboratory was launched, focusing on research in the important new area of cloud computing. Unique in the UK, Stack aims to become an international centre of excellence for research and teaching in cloud computing and provides advice and information to businesses interested in cloud-based services. In January 2011, the IRMOS EU-funded project developed a real-time cloud platform, enabling interactive applications to be executed in cloud infrastructures. In June 2011, two Indian Universities i.e. University of Petroleum and Energy Studies and University of Technology and Management introduced cloud computing as a subject in India, in collaboration with IBM. In October 2012, the Centre For Development of Advanced Computing released an open source, complete cloud service, software suite called "Meghdoot".