Cloud computing is a way of referring to the use of shared computing resources, and it is an alternative to having local servers handle applications. Cloud computing groups together large numbers of compute servers and other resources and typically offers their combined capacity on an on-demand, pay-per-cycle basis. The end users of a cloud computing network usually have no idea where the servers are physically located—they just spin up their application and start working. According to Wang and von Laszewski, Cloud computing can be defined as “A computing Cloud is a set of network enabled services, providing scalable, QoS guaranteed, normally personalized, inexpensive computing platforms on demand, which could be accessed in a simple and pervasive way”. According to GuiyiWei et al Cloud computing is a natural evolution for data and computation centers with automated systems management, workload balancing, and virtualization technologies. Cloudbased services integrate globally distributed resources into seamless computing platforms. Recently, a great deal of applications are increasingly focusing on thirdparty resources hosted across the Internet and each has varying capacity. Fig. ‘ show the logical diagram of cloud computing.
It is a paradigm shift (change in a fundamental model of events) following the shift from mainframe to client-server. It is a paradigm shift (change in a fundamental model of events) following the shift from mainframe to client-server. Details are abstracted from the users who no longer have need of, expertise in, or control over the technology infrastructure “in the cloud” that supports them. Cloud computing describes a new supplement, Details are abstracted from the users who no longer have need of, expertise in, or control over the technology infrastructure “in the cloud” that supports them. consumption and delivery model for IT services based on the Internet, and it typically involves the provision of dynamically scalable and often virtualized resources as a service over the Internet It is a byproduct and consequence of the ease-ofaccess to remote computing sites provided by the Internet.
Cloud Service Characteristics
The operational environment for cloud computing supports three categories of informational resources for achieving agility, availability, collaboration, and elasticity in the deployment and use of cloud services that include software, information, and cloud infrastructure. The software category includes system software, application software, infrastructure software, and accessibility software. The information category refers to large collections of data and the requisite database and management facilities needed for efficient and secure storage utilization. The category of cloud infrastructure is comprised of computer resources, network facilities, and the fabric for scalable consumer operations. We are going to adopt a description of a cloud framework that necessarily includes three forms of description: terminology, architectural requirements, and a reference model. The description generally adheres to the National Institute of Standards and Technology (NIST) cloud-computing paradigm.
Agility generally refers to the ability to respond in a timely manner to market and product changes through business alignment, which is achieved by decreasing the lead time to deploy a new application by reducing or eliminating the effect of training, hardware acquisition, and software acquirement. Thus, the IT department is able to respond more quickly to business needs. Availability concerns two aspects of computer utilization: the time that the facilities are available for use and the scope of the resources that are available. Cloud computing facilitates collaboration through network access, provided that the software tools for end user cooperation are available. Elasticity is the characteristic of cloud services that permits computing and storage capability to be scaled up to meet demands on an on-demand basis through resource pooling.
Based on this brief assessment, we can characterize cloud computing as possessing the following characteristics:
* On-demand self service
* Broad network access
* Resource pooling
* Rapid elasticity
* Measured service
Cloud Computing Utilization
There are four main actors – so to speak – in cloud computing: the cloud service provider, the software service provider, the customer, and the user. Each of the actors represents centers of computer-related activity that can overlap to some degree. The cloud service provider (CSP) owns the infrastructure, hardware, software, and network facilities needed to supply cloud computing services managed by a cloud operating system. The CSP performs a function known as hosting that can be used to run computer programs, referred to as applications. This facility, known in some circles, as a cloud platform (CP), can be regarded as an application service that runs in the cloud. More specifically, a cloud platform provides services to applications in the same manner that “software as a service” programs provide services to clients using the cloud as a transport medium. A cloud platform is as much about operating in the cloud, as it is about developing applications for the cloud. A software service provider develops applications that are used by customers to obtain computing services. The SSP can be an independent software vendor (ISV) or an organization that develops a software package that uses the CP as a delivery vehicle for computing and provides application services to customers. ISV software can be used by many customers in the usual fashion for software deployment. When it is shared during operation to achieve economy-of-scale, it is regarded as a multitenant model, wherein each customer is one of the tenants. The customer (C) is typically an enterprise that is comprised of several employees that use the application and are regarded as users. The user (U) is probably going to be a person that uses the cloud computing service via a web browser in one of the following capacities: as an employee of an organization that is contracted to use SaaS provided by an ISV or acquired independently to run in the cloud on a cloud platform; or as a user of third-party SaaS developed by an ISV or the CSP. The four relevant scenarios are summarized by the following schema:
CSP – CP – ISV – C – U
CSP – CP – ISV – U
CSP – CP – C – U
CSP – CP – U
For example, you will be using scenario CSP – CP – ISV – C – U if your company has acquired an operational package from a software vendor and is hosting that software in the cloud. Similarly, you will be using scenario CSP -CP – U if you are using an office package provided by a CSP and accessed via your browser. This form of conceptualization is important from a privacy point-of-view, because each exchange between modules represents a touch point for privacy concerns.
Benefits of Cloud Computing
* Cloud technology is paid incrementally, saving organizations money.
* Organizations can store more data than on private computer systems.
* No longer do IT personnel need to worry about keeping software up to date.
* Cloud computing offers much more flexibility than past computing methods.
* Employees can access information wherever they are, rather than having to remain at their desks.
* No longer having to worry about constant server updates and other computing issues, government organizations will be free to concentrate on innovation.
* Flexibility to choose multiple vendors that provide reliable and scalable business services, development environments, and infrastructure that can be leveraged out of the box and billed on a metered basis—with no long term contracts
* Elastic nature of the infrastructure to rapidly allocate and de-allocate massively scalable resources to business services on a demand basis.
* Cost allocation flexibility for customers wanting to move CapEx into OpEx
* Reduced costs due to operational efficiencies, and more rapid deployment of new business services