75,676 research outputs found

    Studio e realizzazione di un sistema di gestione fault tolerance applicato ad una piattaforma di calcolo distribuito a livello geografico

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    The last decade has seen an unprecedented growth in grid infrastructures. Grid characteristics, such as high heterogeneity, complexity and distribution create many new technical challenges, which need to be addressed. Among these technical challenges, failure management is a key area, important for both the applications and for the grid operation activities. In this thesis work i have undertaken a comprehensive analysis and assessment of several services of the gLite middleware currently in use in the EGEE Grid, the largest grid infrastructure in the world. Sites in the EGEE production grid infrastructure are required to provide their services on a continuous basis. The same is true for central grid infrastructure services. Therefore, it is important not only to know the current status of the various sites and central services but also to obtain information about this status in the long run. Service level agreement (SLA) negotiation plays a very important role in manufacturing grid. I extended the Nagios monitoring framework with high availability features in order to implementan efficient grid monitoring system. The main goal of this system is to achieve better availability of grid hosts and services, by precise problem detection and instant notification. This would also enable utilizing system's mechanisms for automatic recovery of services in order to improve the present rates, and so improve the availability and reliability of the EGEE grid production infrastructure. The aim of such an initiative is to provide a sustainable infrastructure based on National Grid Initiatives (NGIs), with the final result of delivering a large-scale production Grid infrastructure able to provide reliable and predictable services

    Technical support for Life Sciences communities on a production grid infrastructure

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    Production operation of large distributed computing infrastructures (DCI) still requires a lot of human intervention to reach acceptable quality of service. This may be achievable for scientific communities with solid IT support, but it remains a show-stopper for others. Some application execution environments are used to hide runtime technical issues from end users. But they mostly aim at fault-tolerance rather than incident resolution, and their operation still requires substantial manpower. A longer-term support activity is thus needed to ensure sustained quality of service for Virtual Organisations (VO). This paper describes how the biomed VO has addressed this challenge by setting up a technical support team. Its organisation, tooling, daily tasks, and procedures are described. Results are shown in terms of resource usage by end users, amount of reported incidents, and developed software tools. Based on our experience, we suggest ways to measure the impact of the technical support, perspectives to decrease its human cost and make it more community-specific.Comment: HealthGrid'12, Amsterdam : Netherlands (2012

    Polish grid infrastructure for science and research

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    Structure, functionality, parameters and organization of the computing Grid in Poland is described, mainly from the perspective of high-energy particle physics community, currently its largest consumer and developer. It represents distributed Tier-2 in the worldwide Grid infrastructure. It also provides services and resources for data-intensive applications in other sciences.Comment: Proceeedings of IEEE Eurocon 2007, Warsaw, Poland, 9-12 Sep. 2007, p.44

    Software Defined Networks based Smart Grid Communication: A Comprehensive Survey

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    The current power grid is no longer a feasible solution due to ever-increasing user demand of electricity, old infrastructure, and reliability issues and thus require transformation to a better grid a.k.a., smart grid (SG). The key features that distinguish SG from the conventional electrical power grid are its capability to perform two-way communication, demand side management, and real time pricing. Despite all these advantages that SG will bring, there are certain issues which are specific to SG communication system. For instance, network management of current SG systems is complex, time consuming, and done manually. Moreover, SG communication (SGC) system is built on different vendor specific devices and protocols. Therefore, the current SG systems are not protocol independent, thus leading to interoperability issue. Software defined network (SDN) has been proposed to monitor and manage the communication networks globally. This article serves as a comprehensive survey on SDN-based SGC. In this article, we first discuss taxonomy of advantages of SDNbased SGC.We then discuss SDN-based SGC architectures, along with case studies. Our article provides an in-depth discussion on routing schemes for SDN-based SGC. We also provide detailed survey of security and privacy schemes applied to SDN-based SGC. We furthermore present challenges, open issues, and future research directions related to SDN-based SGC.Comment: Accepte
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