Cloud Computing: A New Era In It Service Delivery

Enterprises strive to reduce computing costs. Many start by consolidating their IT operations and later introducing virtualization technologies. Reducing costs, accelerating processes and simplifying management are all vital to the success of an effective IT infrastructure. Companies are increasingly turning to more flexible IT environments to help them realise these goals. Cloud computing is clearly one of today’s most appealing technology areas due, at least in part, to its cost-efficiency and flexibility Cloud computing enables tasks to be assigned to a combination of software and services over a network. This network of servers is the cloud. Cloud computing can help businesses transform their existing server infrastructures into dynamic environments, expanding and reducing server capacity depending on their requirements. This paper describes cloud computing, a computing platform for the next generation of the Internet. The paper defines clouds, explains the business benefits of cloud computing, and outlines cloud architecture and its major components.

1.    Introduction:Computing is being transformed to a model consisting of services that are commoditized and delivered in a manner similar to traditional utilities such as water, electricity, gas, and telephony. In such a model, users access services based on their requirements without regard to where the services are hosted or how they are delivered. Several computing paradigms have promised to deliver this utility computing vision and these include cluster computing, Grid computing, and more recently Cloud computing. The latter term denotes the infrastructure as a Cloud from which businesses and users are able to access applications from anywhere in the world on demand. Thus, the computing world is rapidly transforming towards developing software for millions to consume as a service, rather than to run on their individual computers. At present, it is common to access content across the Internet independently without reference to the underlying hosting infrastructure. This infrastructure consists of data centers that are monitored and maintained around the clock by content providers. Cloud computing is an extension of this paradigm wherein the capabilities of business applications are exposed as sophisticated services that can be accessed over a network. Consumers, such as enterprises, are attracted by the opportunity for reducing or eliminating costs associated with in-house provision of these services. However, since cloud applications may be crucial to the core business operations of the consumers, it is essential that the consumers have guarantees from providers on service delivery. Cloud computing is a style of computing whose foundation is the delivery of services, software and processing capacity using private or public networks. The focus of cloud computing is the user experience, and the essence is to decouple the delivery of computing services from the underlying technology. Beyond the user interface, the technology behind the cloud remains invisible to the user, making cloud computing incredibly user-friendly.

Cloud computing is an emerging approach to shared infrastructure in which large pools of systems are linked together in private or public networks to provide IT services.
 
2.    Hat is Cloud Computing? : In the 1960s and 1970s, the first wave of computing consisted of large, expensive, labor-intensive, monolithic servers that could be considered the forefathers of the mainframe. Internal resources were pooled and heavy use was made of virtualization to ensure that the very best was made of these very expensive resources. In the 1980s and 1990s, with the rise of PCs, the shrinking costs of networking and computing infrastructure, and a need for more agility, client/server provided the ability to split the application tier away from the server tier. This was done to support distributed clients running richer user interfaces and also to reduce costs by offloading the user handling, application workloads off monolithic servers. These larger servers remained to address massive batch processing and scientific workloads. In the 2000’s, as data centers started to fill out, and power, space and cooling became more and more expensive, concepts such as commodity grid computing and virtualization started to become established. Cloud computing takes these concepts further by allowing self-service, metered usage and more automated dynamic resource and workload management practices. As services became more and more distributed, SOA emerged as a methodology to integrate and orchestrate distributed business services. This need exists today, as customers require integration between public, private, and in-house services. In many cases, today’s Cloud was based on foundational concepts that addressed an early need to best leverage computing resources almost 40 years ago. A large monolithic server was easy to secure relative to a virtualized resource on the Cloud. Security is still the number one concern of many customers who want to leverage public Cloud services today.
A new generation of technology is transforming the world of computing. Internet-based data storage and services-also known as “cloud computing”-are rapidly emerging to complement the traditional model of software running and data being stored on desktop PCs and servers. In simple terms, cloud computing is a way to enhance computing experiences by enabling users to access software applications and data that are stored at off-site datacenters rather than on the user’s own device or PC or at an organization’s on-site datacenter.E-mail, instant messaging, business software, and Web content management are among the many applications that may be offered via a cloud environment.
Cloud computing can be defined as a type of parallel and distributed system consisting of a collection of interconnected and virtualized computers that are dynamically provisioned and presented as one or more unified computing resources based on service-level agreements established through negotiation between the service provider and consumers. Some examples of emerging Cloud computing infrastructures are Microsoft Azure , Amazon EC2, Google App Engine, and Aneka . Emerging Cloud applications such as social networking, gaming portals, business applications, content delivery, and scientific workflows operate at the highest layer of the architecture. Actual usage patterns of many real-world applications vary with time, most of the time in unpredictable ways. These applications have different Quality of Service (QoS) requirements depending on time criticality and users’ interaction patterns (online/offline). Cloud is based on a foundation of virtualization, in which pools of (virtualized) resources are dynamically organized for the benefit of software applications and services.


Intentions To Adopt Cloud Computing
 
Source : IDC Enterprise Panel , August 2008.
Gartner recently defined cloud computing as “a style of computing in which massively scalable IT-enabled capabilities are delivered ‘as a service’ to multiple customers using Internet technologies.” This definition seems appropriate because it positions cloud computing as a business enabler rather than a technical construct-a function that IT leaders are finding increasingly necessary as the role of IT evolves.
 The IT capabilities offered through cloud computing can be grouped into three general categories:
    Developer tools (Platform as a Service, or PaaS)
Description: This model delivers a computing platform that gives users the resources they need to develop and deploy web-based applications without purchasing, installing, and managing the supporting hardware and software systems.
Enterprise potential: Growing. PaaS was originally targeted at independent developers who didn’t have the resources to build and manage their own data centers. Enterprise developers are finding these tools to be useful up to the point of deployment, when they may need to move the application to a more enterprise-oriented hosting environment.
    Business applications (Software as a Service, or SaaS)
Description: This model makes it possible for organizations to license applications as a service on demand, thus avoiding the need to purchase and maintain software installations across their business. SaaS is customarily offered via a subscription model with fees based on usage. SaaS providers usually offer both the software and support, and often partner with third-party hosting providers that help operate and support their SaaS systems.
Enterprise potential: Established. This is the most mature cloud-based service model. SaaS is targeted at enterprises looking to gain efficiencies by standardizing certain functions (customer relationship management [CRM], payroll, other accounting functions) on a common software platform that can be delivered through the cloud. SaaS is a good option for enterprise applications that don’t require a great deal of customization .
    Infrastructure Resources (infrastructure as a Service, or iaaS)
Description: In this model, the cloud is a form of utility infrastructure. The primary attraction is that an enterprise can get all the computing capacity it needs for vital business applications without having to design, acquire, build, and manage an underlying infrastructure.
Enterprise potential: Growing. As the demand for computing increases, larger amounts of processing power and data storage are required to support important enterprise applications. Organizations are realizing that an innovative model of computing will be necessary to manage this vast information infrastructure. IaaS offers increasingly widespread appeal because it creates a shared pool of resources that can be allocated on demand to any application as needed by the enterprise. This approach also supports a pay-per-use or measured usage billing model, more closely matching your cost to what your business requires.
ICT managers preparing for adoption of cloud computing should take these critical steps:
• Identify all potential opportunities for switching from existing computing arrangements to cloud services.
• Assure that in-house infrastructure complements cloud-based services. Virtualization will be a key element of a compatible infrastructure.
• Develop a cost/benefit and risk-evaluation framework to support decisions about where, when, and how cloud services can be adopted.
• Develop a roadmap for optimizing the current ICT environment for adoption of public and/or private cloud services.
• Identify which data cannot be held in public cloud computing environments for legal and/or risk-mitigation reasons.
• Identify and secure in-house competencies required to manage effective adoption of cloud services.
• Designate a cross-functional team to monitor cloud computing services, providers, and standards, and to determine if they affect the roadmap.
• Evaluate technical challenges that must be addressed when moving any current information or applications into a cloud environment. Experiment with and pilot various services—both internal and external—to identify where issues will arise.
• Ensure that the networking environment is ready for cloud computing.
Reducing costs, accelerating processes and simplifying management are all vital to the success of an effective IT infrastructure. Companies are increasingly turning to more flexible IT environments to help them realise these goals. Cloud computing enables tasks to be assigned to a combination of software and services over a network. This network of servers is the cloud. Cloud computing can help businesses transform their existing server infrastructures into dynamic environments, expanding and reducing server capacity depending on their requirements.
    Why cloud computing?
Adopting a cloud computing strategy can help businesses conduct their core business activities with less hassle and greater efficiency. Companies can maximise the use of their existing hardware to plan for and serve specific peaks in usage. Thousands of virtual machines and applications can be managed more easily using a cloud-like environment. Businesses can also save on power costs as they reduce the number of servers required. And with IT staff spending less time managing and monitoring the data centre, IT teams are well placed to further streamline their operations as staff complete more work on fewer machines.
    What is a cloud?
Cloud computing is a term used to describe both a platform and type of application. A cloud computing platform dynamically provisions, configures, reconfigures, and deprovisions servers as needed. Servers in the cloud can be physical machines or virtual machines. Advanced clouds typically include other computing resources such as storage area networks (SANs), network equipment, firewall and other security devices. Cloud computing also describes applications that are extended to be accessible through the Internet. These cloud applications use large data centers and powerful servers that host Web applications and Web services. Anyone with a suitable Internet connection and a standard browser can access a cloud application.
Definition
A cloud is a pool of virtualized computer resources. A cloud can: Host a variety of different workloads, including batch-style back-end jobs and interactive, user-facing applications
• Allow workloads to be deployed and scaled-out quickly through the rapid provisioning of virtual machines or physical machines
• Support redundant, self-recovering, highly scalable programming models that allow workloads to recover from many unavoidable hardware/software failures
• Monitor resource use in real time to enable rebalancing of allocations when needed Cloud computing environments support grid computing by quickly providing physical and virtual servers on which the grid applications can run. Cloud computing should not be confused with grid computing. Grid computing involves dividing a large task into many smaller tasks that run in parallel on separate servers. Grids require many computers, typically in the thousands, and commonly use servers, desktops, and laptops. Clouds also support nongrid environments, such as a three-tier Web architecture running standard or Web 2.0 applications. A cloud is more than a collection of computer resources because a cloud provides a mechanism to manage those resources. A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.).
A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people.
A cloud service has three distinct characteristics that differentiate it from traditional hosting. It is
sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as
little of a service as they want at any given time; and the service is fully managed by the provider
(the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed
Internet and a weak economy, have accelerated interest in cloud computing.
IT organizations can choose to deploy applications on public, private, or hybrid clouds, each of which has its trade-offs. Companies may make a number of considerations with regard to which cloud computing model they choose to employ, and they might use more than one model to solve different problems. An application needed on a temporary basis might be best suited for deployment in a public cloud because it helps to avoid the need to purchase additional equipment to solve a temporary need.
Private cloud. The cloud infrastructure is operated solely for an organization. it may be managed by the organization or a third party, and may exist on or off the premises. Private clouds are built for the exclusive use of one client, providing the utmost control over data, security, and quality of service. The company owns the infrastructure and has control over how applications are deployed on it. Private clouds may be deployed in an enterprise datacenter, and they also may be deployed at a colocation facility. Private clouds can be built and managed by a company’s own IT organization or by a cloud provider. This model gives companies a high level of control over the use of cloud resources while bringing in the expertise needed to establish and operate the environment.
Community Cloud. The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.
Public Cloud. The cloud infrastructure is made available to the general public or a large industry group, and is owned by an organization selling cloud services. Public clouds are run by third parties, and applications from different customers are likely to be mixed together on the cloud’s servers, storage systems, and networks. Public clouds are most often hosted away from customer premises, and they provide a way to reduce customer risk and cost by providing a flexible, even temporary extension to enterprise infrastructure. If a public cloud is implemented with performance, security, and data locality in mind, the existence of other applications running in the cloud should be transparent to both cloud architects and end users. Indeed, one of the benefits of public clouds is that they can be much larger than a company’s private cloud might be, offering the ability to scale up and down on demand, and shifting infrastructure risks from the enterprise to the cloud provider, if even just temporarily. Portions of a public cloud can be carved out for the exclusive use of a single client, creating a virtual private datacenter. Rather than being limited to deploying virtual machine images in a public cloud, a virtual private datacenter gives customers greater visibility into its infrastructure. Now customers can manipulate not just virtual machine images, but also servers, storage systems, network devices, and network topology. Creating a virtual private datacenter with all components located in the same facility helps to lessen the issue of data locality because bandwidth is abundant and typically free when connecting resources within the same facility.
Hybrid Cloud. The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting). Hybrid clouds combine both public and private cloud models . They can help to provide on-demand, externally provisioned scale. The ability to augment a private cloud with the resources of a public cloud can be used to maintain service levels in the face of rapid workload fluctuations. A hybrid cloud also can be used to handle planned workload spikes. Sometimes called “surge computing,” a public cloud can be used to perform periodic tasks that can be deployed easily on a public cloud. Hybrid clouds introduce the complexity of determining how to distribute applications across both a public and private cloud. Among the issues that need to be considered is the relationship between data and processing resources. If the data is small, or the application is stateless, a hybrid cloud can be much more successful than if large amounts of data must be transferred into a public cloud for a small amount of processing.
Cloud computing infrastructures can allow enterprises to achieve more efficient use of their IT hardware and software investments. They do this by breaking down the physical barriers inherent
in isolated systems, and automating the management of the group of systems as a single entity. Cloud computing is an example of an ultimately virtualized system, and a natural evolution for data centers that employ automated systems management, workload balancing, and virtualization
technologies.
Benefits of Cloud Computing
    CostSavings
Organizations can reduce or eliminate ICT capital expenditures and decrease ongoing operating expenditures by paying only for the services they use and, potentially, by reducing or redeploying their ICT staffs.
    Ease of implementation
Without the need to purchase hardware, software licenses, or implementation services, an organization can deploy cloud computing rapidly.
    Flexibility
Cloud computing offers more flexibility (often called “elasticity”) in matching ICT resources to business functions than past computing methods. It can also increase staff mobility by enabling access to business information and applications from a wider range of locations and/or devices.
    Scalibility
Organizations using cloud computing need not scramble to secure additional, higher-caliber hardware and software when user loads increase, but can instead add and subtract capacity as the network load dictates.
    Access to Top end IT Capabilities
Particularly for smaller organizations, cloud computing can allow access to higher-caliber hardware, software, and ICT staff than they can attract and/or afford themselves.
    Redeployment of IT Staff
By reducing or eliminating constant server updates and other computing issues, and by cutting expenditures of time and money on application development, organizations can focus ICT staff on higher-value tasks.
    Focus on Core Competencies
Arguably, the ability to run data centers and to develop and manage software applications is not necessarily a core competency of most organizations. Cloud computing can make it much easier to reduce or shed these functions, allowing organizations to concentrate on critical issues such as (in government) the development of policy and the design and delivery of public services.
    Sustainbility
Arguably, the ability to run data centers and to develop and manage software applications is not necessarily a core competency of most organizations. Cloud computing can make it much easier to reduce or shed these functions, allowing organizations to concentrate on critical issues such as (in government) the development of policy and the design and delivery of public services.

3.    Conclusion: Cloud computing offers real alternatives to IT departments for improved flexibility and lower cost. Markets are developing for the delivery of software applications, platforms, and infrastructure as a service to IT departments over the “cloud”. These services are readily accessible on a pay-per-use basis and offer great alternatives to businesses that need the flexibility to rent infrastructure on a temporary basis or to reduce capital costs. Client-plus-cloud computing offers enhanced choice, flexibility, operational efficiency and cost savings for businesses and consumers. To take full advantage of these benefits, users must be given reliable assurances regarding the privacy and security of their online data.

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