-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. INTRODUCTIONCloud computing as a technology is difficult to define because it is evolving without a clear start point and no clear prediction of its future course. The cloud technology seems to be in flax, hence it may be one of the foundations of the next generation of computing.It's built on a solid array of fundamental and proven technologies: virtualization, grid computing, service oriented architectures, distributed computing, broadband networks, browser as a platform, free and open source software, autonomic systems, web application frameworks Service level agreements.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 is different from but related with grid computing, utility computing and transparent computing. Grid computing [1] is a form of distributed computing whereby a "super and virtual computer" composed of a cluster of networked, loosely-coupled computers acts in concert to perform very large tasks. Grid computing involves dividing a large task into many smaller tasks that run in parallel on separate...