1,894 research outputs found

    A Case for Cooperative and Incentive-Based Coupling of Distributed Clusters

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    Research interest in Grid computing has grown significantly over the past five years. Management of distributed resources is one of the key issues in Grid computing. Central to management of resources is the effectiveness of resource allocation as it determines the overall utility of the system. The current approaches to superscheduling in a grid environment are non-coordinated since application level schedulers or brokers make scheduling decisions independently of the others in the system. Clearly, this can exacerbate the load sharing and utilization problems of distributed resources due to suboptimal schedules that are likely to occur. To overcome these limitations, we propose a mechanism for coordinated sharing of distributed clusters based on computational economy. The resulting environment, called \emph{Grid-Federation}, allows the transparent use of resources from the federation when local resources are insufficient to meet its users' requirements. The use of computational economy methodology in coordinating resource allocation not only facilitates the QoS based scheduling, but also enhances utility delivered by resources.Comment: 22 pages, extended version of the conference paper published at IEEE Cluster'05, Boston, M

    A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

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    Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.Comment: 46 pages, 16 figures, Technical Repor

    Performance Analysis of Publish/Subscribe Systems

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    The Desktop Grid offers solutions to overcome several challenges and to answer increasingly needs of scientific computing. Its technology consists mainly in exploiting resources, geographically dispersed, to treat complex applications needing big power of calculation and/or important storage capacity. However, as resources number increases, the need for scalability, self-organisation, dynamic reconfigurations, decentralisation and performance becomes more and more essential. Since such properties are exhibited by P2P systems, the convergence of grid computing and P2P computing seems natural. In this context, this paper evaluates the scalability and performance of P2P tools for discovering and registering services. Three protocols are used for this purpose: Bonjour, Avahi and Free-Pastry. We have studied the behaviour of theses protocols related to two criteria: the elapsed time for registrations services and the needed time to discover new services. Our aim is to analyse these results in order to choose the best protocol we can use in order to create a decentralised middleware for desktop grid

    DĂ©couverte et allocation des ressources pour le traitement de requĂȘtes dans les systĂšmes grilles

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    De nos jours, les systĂšmes Grille, grĂące Ă  leur importante capacitĂ© de calcul et de stockage ainsi que leur disponibilitĂ©, constituent l'un des plus intĂ©ressants environnements informatiques. Dans beaucoup de diffĂ©rents domaines, on constate l'utilisation frĂ©quente des facilitĂ©s que les environnements Grille procurent. Le traitement des requĂȘtes distribuĂ©es est l'un de ces domaines oĂč il existe de grandes activitĂ©s de recherche en cours, pour transfĂ©rer l'environnement sous-jacent des systĂšmes distribuĂ©s et parallĂšles Ă  l'environnement Grille. Dans le cadre de cette thĂšse, nous nous concentrons sur la dĂ©couverte des ressources et des algorithmes d'allocation de ressources pour le traitement des requĂȘtes dans les environnements Grille. Pour ce faire, nous proposons un algorithme de dĂ©couverte des ressources pour le traitement des requĂȘtes dans les systĂšmes Grille en introduisant le contrĂŽle de topologie auto-stabilisant et l'algorithme de dĂ©couverte des ressources dirigĂ© par l'Ă©lection convergente. Ensuite, nous prĂ©sentons un algorithme d'allocation des ressources, qui rĂ©alise l'allocation des ressources pour les requĂȘtes d'opĂ©rateur de jointure simple par la gĂ©nĂ©ration d'un espace de recherche rĂ©duit pour les nƓuds candidats et en tenant compte des proximitĂ©s des candidats aux sources de donnĂ©es. Nous prĂ©sentons Ă©galement un autre algorithme d'allocation des ressources pour les requĂȘtes d'opĂ©rateurs de jointure multiple. Enfin, on propose un algorithme d'allocation de ressources, qui apporte une tolĂ©rance aux pannes lors de l'exĂ©cution de la requĂȘte par l'utilisation de la rĂ©plication passive d'opĂ©rateurs Ă  Ă©tat. La contribution gĂ©nĂ©rale de cette thĂšse est double. PremiĂšrement, nous proposons un nouvel algorithme de dĂ©couverte de ressource en tenant compte des caractĂ©ristiques des environnements Grille. Nous nous adressons Ă©galement aux problĂšmes d'extensibilitĂ© et de dynamicitĂ© en construisant une topologie efficace sur l'environnement Grille et en utilisant le concept d'auto-stabilisation, et par la suite nous adressons le problĂšme de l'hĂ©tĂ©rogĂ©nĂ©itĂ© en proposant l'algorithme de dĂ©couverte de ressources dirigĂ© par l'Ă©lection convergente. La deuxiĂšme contribution de cette thĂšse est la proposition d'un nouvel algorithme d'allocation des ressources en tenant compte des caractĂ©ristiques de l'environnement Grille. Nous abordons les problĂšmes causĂ©s par la grande Ă©chelle caractĂ©ristique en rĂ©duisant l'espace de recherche pour les ressources candidats. De ce fait nous rĂ©duisons les coĂ»ts de communication au cours de l'exĂ©cution de la requĂȘte en allouant des nƓuds au plus prĂšs des sources de donnĂ©es. Et enfin nous traitons la dynamicitĂ© des nƓuds, du point de vue de leur existence dans le systĂšme, en proposant un algorithme d'affectation des ressources avec une tolĂ©rance aux pannes.Grid systems are today's one of the most interesting computing environments because of their large computing and storage capabilities and their availability. Many different domains profit the facilities of grid environments. Distributed query processing is one of these domains in which there exists large amounts of ongoing research to port the underlying environment from distributed and parallel systems to the grid environment. In this thesis, we focus on resource discovery and resource allocation algorithms for query processing in grid environments. For this, we propose resource discovery algorithm for query processing in grid systems by introducing self-stabilizing topology control and converge-cast based resource discovery algorithms. Then, we propose a resource allocation algorithm, which realizes allocation of resources for single join operator queries by generating a reduced search space for the candidate nodes and by considering proximities of candidates to the data sources. We also propose another resource allocation algorithm for queries with multiple join operators. Lastly, we propose a fault-tolerant resource allocation algorithm, which provides fault-tolerance during the execution of the query by the use of passive replication of stateful operators. The general contribution of this thesis is twofold. First, we propose a new resource discovery algorithm by considering the characteristics of the grid environments. We address scalability and dynamicity problems by constructing an efficient topology over the grid environment using the self-stabilization concept; and we deal with the heterogeneity problem by proposing the converge-cast based resource discovery algorithm. The second main contribution of this thesis is the proposition of a new resource allocation algorithm considering the characteristics of the grid environment. We tackle the scalability problem by reducing the search space for candidate resources. We decrease the communication costs during the query execution by allocating nodes closer to the data sources. And finally we deal with the dynamicity of nodes, in terms of their existence in the system, by proposing the fault-tolerant resource allocation algorithm

    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
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