Accounting Facilities in the European Supercomputing Grid DEISA

Account management and resource usage monitoring are essential services for production Grids. The scope of a production Grid infrastructure, the heterogeneity of resources and services, the typical community usage profiles, and the depth of integration of the resource providers regarding operational procedures and policies imply specific requirements for accounting facilities. We present the accounting facilities currently used in production in the Distributed European Infra-structure for the Supercomputing Applications (DEISA). DEISA is a consortium of leading national supercomputing centres currently deploying and operating a persistent, production quality, distributed su-percomputing environment with continental scope. The DEISA accounting facilities gather information from the site-local batch systems and the distributed DEISA user administration system, and generate XML usage records conforming to the OGF usage record specification which are then stored locally in a XML data base at each DEISA site. The distributed accounting information can be fetched by clients such as users, project supervisors, site accounting managers and DEISA supervisors. The information is made available by site-local WSRF-compliant accounting information services that allow for a fine-grained setting of access rights. Each authorized client gets a specific view on the accounting information according to one of the following roles: a) a site accounting manager imports usage records of related home-site users from all DEISA sites for longterm archiving, b) a project supervisor retrieves information to assess the resource usage by his project partners, c) a DEISA supervisor (e.g. someone overlooking the usage on behalf of the DEISA executive committee) gets a report on the global usage of DEISA resources, and d) the user who can retrieve all the accounting information related to his own jobs. The privacy and integrity of the data provided and transferred from the accounting information service running at each site is guaranteed using X.509 certificates for mutual authentication and secure communication channels

dHvA EFFECT IN THE NORMAL STATE OF THE HIGH TcA-15 SUPERCONDUCTORS Nb3Sn AND V3Si

Des oscillations dHvA ont été observées pour Nb3Sn, dans le plan (110) et pour V3Si, dans deux orientations, en utilisant des monocristaux de haut rapport de résistance et des champs magnétiques allant jusqu'à 400 kOe. Les fréquences dHvA obtenues pour Nb3Sn peuvent être interprétées comme une série d'ellipsoides concentriques centrées en M.dHvA oscillations have been observed in Nb3Sn in the (110) plane and in V3Si at two orientations using single crystals of high resistance ratio and magnetic fields up to 4003kOe. The dHvA frequency data for Nb3Sn can be interpred as a series of nested ellipsoides centred at M

FERMI SURFACE AND dHvA EFFECT IN THE NORMAL STATE OF HIGH Tc A-15 SUPERCONDUCTORS

La surface de Fermi de Nb3Sn a été déterminée par des calculs de bande de type APW. Des oscillations de Haas-van Alphen (dHvA) ont été observées dans Nb3Sn et dans V3Si en accord avec la surface de Fermi calculée. Pour ces deux composés, à l'état normal des oscillations dHvA ont été mesurées avec des monocristaux ayant un haut rapport de résistivité plongés dans des champs magnétiques allant jusqu'à 400 kOe et les nouveaux détails de la surface de Fermi ont été mis en évidence et en particulier une structure ellipsoïdale osculatrice autour de M et une grande structure cubique autour de Γ.The Fermi surface of Nb3Sn has been derived form an APW band calculation. de Haas-van Alphen (dHvA) oscillations have been observed in Nb3Sn and V3Si which give a consistent FS description. Using single crystals of high resistance ratio's and magnetic fields up to 400 kOe, dHvA oscillations have been seen in the normal state for both specimens. New features of the Fermi surface include osculated ellipsoidal structure around M, and a large cubical structure around Γ

DEISA - Distributed European Infrastructure for Supercomputing Applications

The paper presents an overview of the current research and achievements of the DEISA project, with a focus on the general concept of the infrastructure, the operational model, application projects and science communities, the DEISA Extreme Computing Initiative, user and application support, operations and technology, services, collaborations and interoperability, and the use of standards and policies. The paper concludes with a discussion about the long-term sustainability of the DEISA infrastructure

On the complexities of utilizing large-scale lightpath-connected distributed cyberinfrastructure

In Autumn 2013, we—an international team of climate scientists, computer scientists, eScience researchers, and e-Infrastructure specialists—participated in the enlighten your research global competition, organized to showcase advanced lightpath technologies in support of state-of-the-art research questions. As one of the winning entries, our enlighten your research global team embarked on a very ambitious project to run an extremely high resolution climate model on a collection of supercomputers distributed over two continents and connected using an advanced 10 G lightpath networking infrastructure. Although good progress was made, we were not able to perform all desired experiments due to a varying combination of technical problems, configuration issues, policy limitations and lack of (budget for) human resources to solve these issues. In this paper, we describe our goals, the technical and non-technical barriers, we encountered and provide recommendations on how these barriers can be removed so future project of this kind may succeed

On the complexities of utilizing large-scale lightpath-connected distributed cyberinfrastructure

In Autumn 2013, we—an international team of climate scientists, computer scientists, eScience researchers, and e-Infrastructure specialists—participated in the enlighten your research global competition, organized to showcase advanced lightpath technologies in support of state-of-the-art research questions. As one of the winning entries, our enlighten your research global team embarked on a very ambitious project to run an extremely high resolution climate model on a collection of supercomputers distributed over two continents and connected using an advanced 10 G lightpath networking infrastructure. Although good progress was made, we were not able to perform all desired experiments due to a varying combination of technical problems, configuration issues, policy limitations and lack of (budget for) human resources to solve these issues. In this paper, we describe our goals, the technical and non-technical barriers, we encountered and provide recommendations on how these barriers can be removed so future project of this kind may succeed.</p