36,197 research outputs found

    Global Grids and Software Toolkits: A Study of Four Grid Middleware Technologies

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    Grid is an infrastructure that involves the integrated and collaborative use of computers, networks, databases and scientific instruments owned and managed by multiple organizations. Grid applications often involve large amounts of data and/or computing resources that require secure resource sharing across organizational boundaries. This makes Grid application management and deployment a complex undertaking. Grid middlewares provide users with seamless computing ability and uniform access to resources in the heterogeneous Grid environment. Several software toolkits and systems have been developed, most of which are results of academic research projects, all over the world. This chapter will focus on four of these middlewares--UNICORE, Globus, Legion and Gridbus. It also presents our implementation of a resource broker for UNICORE as this functionality was not supported in it. A comparison of these systems on the basis of the architecture, implementation model and several other features is included.Comment: 19 pages, 10 figure

    A Taxonomy of Workflow Management Systems for Grid Computing

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    With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed resources. Such application scenarios require means for composing and executing complex workflows. Therefore, many efforts have been made towards the development of workflow management systems for Grid computing. In this paper, we propose a taxonomy that characterizes and classifies various approaches for building and executing workflows on Grids. We also survey several representative Grid workflow systems developed by various projects world-wide to demonstrate the comprehensiveness of the taxonomy. The taxonomy not only highlights the design and engineering similarities and differences of state-of-the-art in Grid workflow systems, but also identifies the areas that need further research.Comment: 29 pages, 15 figure

    Analysis of current middleware used in peer-to-peer and grid implementations for enhancement by catallactic mechanisms

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    This deliverable describes the work done in task 3.1, Middleware analysis: Analysis of current middleware used in peer-to-peer and grid implementations for enhancement by catallactic mechanisms from work package 3, Middleware Implementation. The document is divided in four parts: The introduction with application scenarios and middleware requirements, Catnets middleware architecture, evaluation of existing middleware toolkits, and conclusions. -- Die Arbeit definiert Anforderungen an Grid und Peer-to-Peer Middleware Architekturen und analysiert diese auf ihre Eignung fĂŒr die prototypische Umsetzung der Katallaxie. Eine Middleware-Architektur fĂŒr die Umsetzung der Katallaxie in Application Layer Netzwerken wird vorgestellt.Grid Computing

    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

    Proof-of-Concept Application - Annual Report Year 1

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    In this document the Cat-COVITE Application for use in the CATNETS Project is introduced and motivated. Furthermore an introduction to the catallactic middleware and Web Services Agreement (WS-Agreement) concepts is given as a basis for the future work. Requirements for the application of Cat-COVITE with in catallactic systems are analysed. Finally the integration of the Cat-COVITE application and the catallactic middleware is described. --Grid Computing

    Library purchasing consortia in the UK: activity, benefits and good practice.

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    Following a brief introduction in Section 1, Section 2 sets out the operational context of library purchasing consortia. A range of key factors have shaped recent developments in the four LIS sectors under consideration (FE, HE, health and public libraries); some have exerted a common influence over all (e.g. information technology, European Commission purchasing directives, new central government, decline in bookfunds); some are sector-specific (e.g. purchasing arrangements, regional administrative frameworks, collaborative partnerships). The structure and markets of the book and periodical publishing industry in the UK are reviewed, with attention paid to historical as well as more recent practice that has had an impact on library supply. Although each component of the LIS purchasing consortia jigsaw displays individual characteristics that have evolved as a response to its own environment, the thread that links them together is constant change. Section 3 presents the results of a survey of identified library purchasing consortia in the four library sectors. It treats common themes of relevance to all consortia arising from information gathered by seminar input, questionnaire and interview. These include models of consortium operation, membership and governance, ‘typical’ composition of consortia in each sector, and links to analogous practice in other library sectors. Common features of the tendering and contract management process are elicited and attention paid to any contribution of procurement professionals. Finally, levels of consortium expenditure and cost savings are estimated from the published statistical record, which readily demonstrate in financial terms the efficiency of the consortial purchase model for all types of library in the United Kingdom. Section 4 presents the results of a survey of suppliers to libraries in the United Kingdom of books and periodicals, the two sectors most commonly represented in current contracts of library purchasing consortia. It sets out in some detail the operating context governing the highly segmented activities of library booksellers, as well as that pertaining to periodicals suppliers (also known as subscription agents). Detailed responses to questions on the effects of library purchasing consortia on suppliers of both materials have been gathered by questionnaire survey and selected follow-up interviews. Results are presented and analysed according to supply sector with attention given to the tendering process, current contracts under way, cross-sectoral clientele, and advantages and inhibitors of consortia supply. Further responses are reported on issues of how consortia have affected suppliers’ volume of trade, operating margins and market stability as perceived in their own business, the library supply sector and the publishing industry. Finally, overall conclusions are drawn and projections made as to future implications for both types of library suppliers. Section 5 synthesises findings, details enabling and inhibiting factors for consortia formation and models of best practice amongst consortia. The scope for cross-sectoral collaboration is discussed and found to be limited at present. Pointers are given for future activity

    Strategies for stimulating poverty-alleviating growth in the rural nonfarm economy in developing countries:

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    "The rural nonfarm economy (RNFE) accounts for roughly 25 percent of full-time rural employment and 35-40 percent of rural incomes across the developing world. This diverse collection of seasonal trading, household-based and large-scale agroprocessing, manufacturing and service activities plays a crucial role in sustaining rural populations, in servicing a growing and modern agriculture, and in supplying local consumer goods and services. In areas where landlessness prevails, rural nonfarm activity offers important economic alternatives for the rural poor....Three key groups currently intervene in the rural nonfarm economy: large private enterprises, non-profit promotional agencies and governments. Large modern corporations take investment, procurement and marketing decisions that powerfully shape opportunities in the rural nonfarm economy throughout much of the Third World...." The authors put forth three basic principles for policy makers who want to ensure equitable growth of the RNFE : (1) Identify key engines of regional growth; (2) Focus on subsector-specific supply chains; and (3) Build flexible institutional coalitions. They conclude that "a prosperous rural nonfarm economy can contribute to both aggregate economic growth and improved welfare of the rural poor." from Executive Summary.Poverty alleviation Developing countries., Rural population., Employment, Non-agricultural Rural areas., Manufacturing industries., Service industries.,
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