1,306 research outputs found

    Robo-line storage: Low latency, high capacity storage systems over geographically distributed networks

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    Rapid advances in high performance computing are making possible more complete and accurate computer-based modeling of complex physical phenomena, such as weather front interactions, dynamics of chemical reactions, numerical aerodynamic analysis of airframes, and ocean-land-atmosphere interactions. Many of these 'grand challenge' applications are as demanding of the underlying storage system, in terms of their capacity and bandwidth requirements, as they are on the computational power of the processor. A global view of the Earth's ocean chlorophyll and land vegetation requires over 2 terabytes of raw satellite image data. In this paper, we describe our planned research program in high capacity, high bandwidth storage systems. The project has four overall goals. First, we will examine new methods for high capacity storage systems, made possible by low cost, small form factor magnetic and optical tape systems. Second, access to the storage system will be low latency and high bandwidth. To achieve this, we must interleave data transfer at all levels of the storage system, including devices, controllers, servers, and communications links. Latency will be reduced by extensive caching throughout the storage hierarchy. Third, we will provide effective management of a storage hierarchy, extending the techniques already developed for the Log Structured File System. Finally, we will construct a protototype high capacity file server, suitable for use on the National Research and Education Network (NREN). Such research must be a Cornerstone of any coherent program in high performance computing and communications

    Middleware-based Database Replication: The Gaps between Theory and Practice

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    The need for high availability and performance in data management systems has been fueling a long running interest in database replication from both academia and industry. However, academic groups often attack replication problems in isolation, overlooking the need for completeness in their solutions, while commercial teams take a holistic approach that often misses opportunities for fundamental innovation. This has created over time a gap between academic research and industrial practice. This paper aims to characterize the gap along three axes: performance, availability, and administration. We build on our own experience developing and deploying replication systems in commercial and academic settings, as well as on a large body of prior related work. We sift through representative examples from the last decade of open-source, academic, and commercial database replication systems and combine this material with case studies from real systems deployed at Fortune 500 customers. We propose two agendas, one for academic research and one for industrial R&D, which we believe can bridge the gap within 5-10 years. This way, we hope to both motivate and help researchers in making the theory and practice of middleware-based database replication more relevant to each other.Comment: 14 pages. Appears in Proc. ACM SIGMOD International Conference on Management of Data, Vancouver, Canada, June 200

    Isolation in Excess Communication: Social Media in the Writing of Sequoia Nagamatsu

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    The Universe at Extreme Scale: Multi-Petaflop Sky Simulation on the BG/Q

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    Remarkable observational advances have established a compelling cross-validated model of the Universe. Yet, two key pillars of this model -- dark matter and dark energy -- remain mysterious. Sky surveys that map billions of galaxies to explore the `Dark Universe', demand a corresponding extreme-scale simulation capability; the HACC (Hybrid/Hardware Accelerated Cosmology Code) framework has been designed to deliver this level of performance now, and into the future. With its novel algorithmic structure, HACC allows flexible tuning across diverse architectures, including accelerated and multi-core systems. On the IBM BG/Q, HACC attains unprecedented scalable performance -- currently 13.94 PFlops at 69.2% of peak and 90% parallel efficiency on 1,572,864 cores with an equal number of MPI ranks, and a concurrency of 6.3 million. This level of performance was achieved at extreme problem sizes, including a benchmark run with more than 3.6 trillion particles, significantly larger than any cosmological simulation yet performed.Comment: 11 pages, 11 figures, final version of paper for talk presented at SC1

    Advanced Simulation and Computing FY12-13 Implementation Plan, Volume 2, Revision 0.5

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    BRINGING E-BUSINESS TO RURAL REGIONS THROUGH TELECENTRE NETWORKS

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    In the present paper, I am trying to emphasize that telecentres � despite the difficulties they are facing due to last years� technological changes � could still be helpful in promoting the principles of the Lisbon Agenda. They could provide access to ICT in rural regions with underdeveloped and remote infrastructure, thus integrating relatively isolated communities into national and international information networks. They could be means of regional and / or rural economic development by transferring expertise in a number of areas, such as agriculture or rural tourism to and from the community. They could also improve the degree of local employment by offering teleworking opportunities. Last, but not least they could support the training of local people by using eLearning techniques, pointing out new regional trajectories to the knowledge economy. Telecentres could play an important role in establishing knowledge society and in reducing the �digital divide� that still exists between different EU-regions. My paper starts by presenting some basic ideas, such as telecentres and their role in rural development, it goes on with a brief overview of the role which telecenter networks could play in the new European informational landscape and it ends with a presentation of the case of Romania.Telecentre, Community Informatics, Regional Economics, Rural Development, Knowledge Society
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