1,721,211 research outputs found
Early experiences with the EGrid testbed
No full textThe Testbed and Applications working group of the European Grid Forum (EGrid) is actively building and experimenting with a grid infrastructure connecting several research-based supercomputing sites located in Europe. The paper reports on our first feasibility study: running a self-migrating version of the Cactus simulation code across the European grid testbed, including “live” remote data visualization and steering from different demonstration booths at Supercomputing 2000, in Dallas, TX. We report on the problems that had to be resolved for this endeavour and identify open research challenges for building production-grade grid environments
A Dynamic Earth Observation System
No full textThe paper presents an overview of SARA/Digital Puglia (Synthetic Aperture Radar Atlas), a remote sensing environment that shows how grid technologies and high performance com- puting can be efficiently used to build dynamic earth observation systems for the management of huge quantities of data coming from space missions and for their on-demand processing and delivering to final users. SARA/Digital Puglia is a grid-enabled, high performance digital library of remote sensing images, developed in a joint research project with CACR/Caltech, ISI/USC and the Italian Space Agency
Towards exascale distributed data management
No full textExascale eScience infrastructures will face important and critical challenges, both from computational and data perspectives. Increasingly complex and parallel scientific codes will lead to the production of a huge amount of data. The large volume of data and the time needed to locate, access, analyze and visualize data will greatly impact on the scientific productivity of scientists and researchers in several domains. Significant improvements in the data management field will increase research productivity in solving complex scientific problems. The exascale scenario will involve a lot of distributed data available at an international level across several countries. Several application domains will produce large volumes of data. For instance, concerning the climate change domain, hundreds of exabytes of data (distributed across several centers) are expected to be available through heterogeneous storage resources (located in data centers as well as in external environments like data grids and data clouds) for access, analysis, post-processing and other scientific activities. Collections of data will be stored at different sites and made available to the users for further analysis and studies. The same will happen for other domains, where exascale high-performance computing applications will generate data at a very high rate (terabytes/s) on million of cores. In the paper, the main challenges that must be taken into account in the exascale context are presented and discussed
The Oasis3 MPI1/2 Parallel Version
Full text linkThis work describes the optimization and parallelization activities performed on the OASIS3 coupler. The test case used for evaluating and profiling the coupler consists on the CMCCMED coupled model developed by the ANS division of the CMCC and currently in production on the NEC SX9 cluster. The experiments highlighted that the most time consuming transformations are the extrapolation of the fields on the masked points (performed in the extrap function) and interpolation (performed in the scriprmp function). The optimization has been mainly focused on reducing the time spent for I/O operations this reduced the coupling time of 27%. The parallelization of the OASIS3 has been a further step for reducing the elapsed time of the whole coupled model. The proposed parallel approach is based on the distribution of the fields among the available processes. Each process is in charge to apply the coupling transformations on the assigned fields. With this approach the number of coupling fields represents an upper bound to the parallelization level.
However this approach can be fully combined with the parallelization based on the geographical domain distribution. The work concludes with a qualitative comparison of the proposed approach with the OASIS3 pseudoparallel version developed by CERFACS
The Desktop Grid Environment Enabler
No full textThis paper describes our Desktop Grid Environment Enabler (DEGREE), a set of Web Services that provides advanced capabilities for grid computing. DEGREE services are based both on the Globus Toolkit and the Grid Resource Broker, a grid portal developed at the University of Lecce. Trusted users can develop innovative, grid-aware applications that seamlessly access computational resources and services exploiting our Web Services independently of platform and programming language
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