584 research outputs found

    A Literature Survey of Cooperative Caching in Content Distribution Networks

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    Content distribution networks (CDNs) which serve to deliver web objects (e.g., documents, applications, music and video, etc.) have seen tremendous growth since its emergence. To minimize the retrieving delay experienced by a user with a request for a web object, caching strategies are often applied - contents are replicated at edges of the network which is closer to the user such that the network distance between the user and the object is reduced. In this literature survey, evolution of caching is studied. A recent research paper [15] in the field of large-scale caching for CDN was chosen to be the anchor paper which serves as a guide to the topic. Research studies after and relevant to the anchor paper are also analyzed to better evaluate the statements and results of the anchor paper and more importantly, to obtain an unbiased view of the large scale collaborate caching systems as a whole.Comment: 5 pages, 5 figure

    InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services

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    Cloud computing providers have setup several data centers at different geographical locations over the Internet in order to optimally serve needs of their customers around the world. However, existing systems do not support mechanisms and policies for dynamically coordinating load distribution among different Cloud-based data centers in order to determine optimal location for hosting application services to achieve reasonable QoS levels. Further, the Cloud computing providers are unable to predict geographic distribution of users consuming their services, hence the load coordination must happen automatically, and distribution of services must change in response to changes in the load. To counter this problem, we advocate creation of federated Cloud computing environment (InterCloud) that facilitates just-in-time, opportunistic, and scalable provisioning of application services, consistently achieving QoS targets under variable workload, resource and network conditions. The overall goal is to create a computing environment that supports dynamic expansion or contraction of capabilities (VMs, services, storage, and database) for handling sudden variations in service demands. This paper presents vision, challenges, and architectural elements of InterCloud for utility-oriented federation of Cloud computing environments. The proposed InterCloud environment supports scaling of applications across multiple vendor clouds. We have validated our approach by conducting a set of rigorous performance evaluation study using the CloudSim toolkit. The results demonstrate that federated Cloud computing model has immense potential as it offers significant performance gains as regards to response time and cost saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape

    Universal Mobile Service Execution Framework for Device-To-Device Collaborations

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    There are high demands of effective and high-performance of collaborations between mobile devices in the places where traditional Internet connections are unavailable, unreliable, or significantly overburdened, such as on a battlefield, disaster zones, isolated rural areas, or crowded public venues. To enable collaboration among the devices in opportunistic networks, code offloading and Remote Method Invocation are the two major mechanisms to ensure code portions of applications are successfully transmitted to and executed on the remote platforms. Although these domains are highly enjoyed in research for a decade, the limitations of multi-device connectivity, system error handling or cross platform compatibility prohibit these technologies from being broadly applied in the mobile industry. To address the above problems, we designed and developed UMSEF - an Universal Mobile Service Execution Framework, which is an innovative and radical approach for mobile computing in opportunistic networks. Our solution is built as a component-based mobile middleware architecture that is flexible and adaptive with multiple network topologies, tolerant for network errors and compatible for multiple platforms. We provided an effective algorithm to estimate the resource availability of a device for higher performance and energy consumption and a novel platform for mobile remote method invocation based on declarative annotations over multi-group device networks. The experiments in reality exposes our approach not only achieve the better performance and energy consumption, but can be extended to large-scaled ubiquitous or IoT systems

    The AliEn system, status and perspectives

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    AliEn is a production environment that implements several components of the Grid paradigm needed to simulate, reconstruct and analyse HEP data in a distributed way. The system is built around Open Source components, uses the Web Services model and standard network protocols to implement the computing platform that is currently being used to produce and analyse Monte Carlo data at over 30 sites on four continents. The aim of this paper is to present the current AliEn architecture and outline its future developments in the light of emerging standards.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 10 pages, Word, 10 figures. PSN MOAT00

    webXice: an Infrastructure for Information Commerce on the WWW

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    Systems for information commerce on the WWW have to support flexible business models if they should be able to cover a wide range of requirements imposed by the different types of information businesses. This leads to non-trivial functional and security requirements both on the provider and consumer side, for which we introduce an architecture and a system implementation, webXice. We focus on the question, how participants with minimal technological requisites, i.e. solely standard Web browsers available, can be technologically enabled to articipate in the information commerce at a system level, while not sacrificing the functionality and security required by an autonomous participant in an information commerce scenario. In particular, we propose an implementation strategy to efficiently support persistent message logging for light-weight clients, that enables clients to collect and manage non-reputiable messages as proofs. We believe that the capability to support minimal system platforms is a necessary precondition for the wide-spread use of any information commerce infrastructure

    Web Services and IT Management in Healthcare and Grid Computing

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    Alma Ata Declaration on Primary Health Care defines , health as not just absence of disease but fitness at all levels i.e.Physically, mentally, Psychologically, spirtually, socially, and so on. RCH emphasizes fitness at all level along with health education and medical education. For the last one decade IT has contributed substantially in the healthcare domain. Tele-Medicine, Health informatics, using IT for Health for Prevention, curing, rehabilitation, Medical Education and accessing resources are the some of them.Web Services, IT Management, IT in healthcare, Health Informatics

    RESTful PUBLISH/SUBSCRIBE FRAMEWORK FOR MOBILE DEVICES

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    The growing popularity of mobile platforms is changing the Internet user’s computing experience. Current studies suggest that the traditional ubiquitous computing landscape is shifting towards more enhanced and broader mobile computing platform consists of large number of heterogeneous devices. Smartphones and tablets begin to replace the desktop as the primary means of interacting with IT resources. While mobile devices facilitate in consuming web resources in the form of web services, the growing demand for consuming services on mobile device is introducing a complex ecosystem in the mobile environment. This research addresses the communication challenges involved in mobile distributed networks and proposes an event-driven communication approach for information dissemination. This research investigates different communication techniques such as synchronous and asynchronous polling and long-polling, server-side push as mechanisms between client-server interactions and the latest web technologies namely HTML5 standard WebSocket as communication protocol within a publish/subscribe paradigm. Finally, this research introduces and evaluates a framework that is hybrid of REST and event-based publish/subscribe for operating in the mobile environment

    Large Scale Distributed Knowledge Infrastructures

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