Reliability of Cloud Computing Services
Anju Mishra · IOSR Journal of Engineering · 2014
Cloud computing is a recently developed new technology for complex systems with massive scale service sharing, which is different from the resource sharing of the grid computing systems.Despite the profound technical challenges involved, reliability is not, at its root, a technical problem, nor will merely technical solution be sufficient.Instead deep economic, political, and cultural adjustments will ultimately be required, along with a major, long-term commitment in each sphere to deploy the requisite technical solutions at scale.Nevertheless, technological advance and enablers have a clear role in supporting such change, and information technology (IT) is a natural bridge between technical and social solutions because it can offer improved communication and transparency for fostering the necessary economic, political, and cultural adjustments.Various types of failures are interleaved in the cloud computing environment, such as overflow failure, timeout failure, resource missing failure, network failure, hardware failure, software failure, and database failure.This paper systematically analyzes cloud computing and models the reliability of the cloud services. .It is a holistic approach that stretches from power to waste to purchasing to education and is a lifecycle management approach to the deployment of IT across an organization using Markov models, Queuing Theory and Graph Theory. I. II. DESCRIPTION OF CLOUD COMPUTINGCloud 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. Cloud Computing ModelCloud computing is an umbrella term used to refer to Internet based development and services Cloud characteristics are given below: Remotely hosted: Services or data are hosted on remote infrastructure. Ubiquitous: Services or data are available from anywhere. Commoditized: The result is a utility computing model similar to traditional that of traditional utilities, like gas and electricity -you pay for what you would want. Essential characteristics: On-demand self-service Broad network access Resource pooling Location independence Rapid elasticity Measured service 2.2.Cloud Service Model Software as a Service (SaaS):Saas(Software as a service) model you are provided with access to application softwares often referred to as ondemand Service.Saas(Software as a service) deliver one application to many-user, regardless of their location, rather than the traditional model of one application per desktop.In Saas there is no need of installation, set up and running of application.These activities to be managed by central location, Service provider.Platform as a Service (PaaS): Platform as a Service (PaaS) brings the benefits that SaaS bought for applications, but over to the software development world.PaaS can be defined as a computing platform that allows the creation of web applications quickly and easily and without the complexity of buying and maintaining the software and infrastructure underneath it. Infrastructure as a Service (IaaS):Infrastructure as a Service (IaaS) is a way of delivering Cloud Computing infrastructureservers, storage, network and operating systemsas an on-demand service.Rather than purchasing servers, software, datacenter space or network equipment, clients instead buy those resources as a fully outsourced service on demand [7]. III.CLOUD DEPLOYMENT MODEL