Результаты поиска по 'Data Management System':
Найдено статей: 15
  1. Kholodkov K.I., Aleshin I.M.
    Exact calculation of a posteriori probability distribution with distributed computing systems
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 539-542

    We'd like to present a specific grid infrastructure and web application development and deployment. The purpose of infrastructure and web application is to solve particular geophysical problems that require heavy computational resources. Here we cover technology overview and connector framework internals. The connector framework links problem-specific routines with middleware in a manner that developer of application doesn't have to be aware of any particular grid software. That is, the web application built with this framework acts as an interface between the user 's web browser and Grid's (often very) own middleware.

    Our distributed computing system is built around Gridway metascheduler. The metascheduler is connected to TORQUE resource managers of virtual compute nodes that are being run atop of compute cluster utilizing the virtualization technology. Such approach offers several notable features that are unavailable to bare-metal compute clusters.

    The first application we've integrated with our framework is seismic anisotropic parameters determination by inversion of SKS and converted phases. We've used probabilistic approach to inverse problem solution based on a posteriory probability distribution function (APDF) formalism. To get the exact solution of the problem we have to compute the values of multidimensional function. Within our implementation we used brute-force APDF calculation on rectangular grid across parameter space.

    The result of computation is stored in relational DBMS and then represented in familiar human-readable form. Application provides several instruments to allow analysis of function's shape by computational results: maximum value distribution, 2D cross-sections of APDF, 2D marginals and a few other tools. During the tests we've run the application against both synthetic and observed data.

    Views (last year): 3.
  2. Kiryanov A.K.
    GridFTP frontend with redirection for DMlite
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 543-547

    One of the most widely used storage solutions in WLCG is a Disk Pool Manager (DPM) developed and supported by SDC/ID group at CERN. Recently DPM went through a massive overhaul to address scalability and extensibility issues of the old code.

    New system was called DMLite. Unlike the old DPM that was based on daemons, DMLite is arranged as a library that can be loaded directly by an application. This approach greatly improves performance and transaction rate by avoiding unnecessary inter-process communication via network as well as threading bottlenecks.

    DMLite has a modular architecture with its core library providing only the very basic functionality. Backends (storage engines) and frontends (data access protocols) are implemented as plug-in modules. Doubtlessly DMLite wouldn't be able to completely replace DPM without GridFTP as it is used for most of the data transfers in WLCG.

    In DPM GridFTP support was implemented in a Data Storage Interface (DSI) module for Globus’ GridFTP server. In DMLite an effort was made to rewrite a GridFTP module from scratch in order to take advantage of new DMLite features and also implement new functionality. The most important improvement over the old version is a redirection capability.

    With old GridFTP frontend a client needed to contact SRM on the head node in order to obtain a transfer URL (TURL) before reading or writing a file. With new GridFTP frontend this is no longer necessary: a client may connect directly to the GridFTP server on the head node and perform file I/O using only logical file names (LFNs). Data channel is then automatically redirected to a proper disk node.

    This renders the most often used part of SRM unnecessary, simplifies file access and improves performance. It also makes DMLite a more appealing choice for non-LHC VOs that were never much interested in SRM.

    With new GridFTP frontend it's also possible to access data on various DMLite-supported backends like HDFS, S3 and legacy DPM.

    Views (last year): 1.
  3. Reed R.G., Cox M.A., Wrigley T., Mellado B.
    A CPU benchmarking characterization of ARM based processors
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 581-586

    Big science projects are producing data at ever increases rates. Typical techniques involve storing the data to disk, after minor filtering, and then processing it in large computer farms. Data production has reached a point where on-line processing is required in order to filter the data down to manageable sizes. A potential solution involves using low-cost, low-power ARM processors in large arrays to provide massive parallelisation for data stream computing (DSC). The main advantage in using System on Chips (SoCs) is inherent in its design philosophy. SoCs are primarily used in mobile devices and hence consume less power while maintaining relatively good performance. A benchmarking characterisation of three different models of ARM processors will be presented.

    Views (last year): 1.
  4. Bogdanov A.V., Thurein Kyaw L.
    Query optimization in relational database systems and cloud computing technology
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 649-655

    Optimization is the heart of relational Database Management System (DMBS). Its can analyzes the SQL statements and determines the most efficient access plan to satisfy every query request. Optimization can solves this problem and analyzes SQL statements specifying which tables and columns are available. And then request the information system and statistical data stored in the system directory, to determine the best method of solving the tasks required to comply with the query requests.

    Views (last year): 1.
  5. Ustimenko O.V.
    Features DIRAC data management
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 741-744

    The report presents an analysis of Big Data storage solutions in different directions. The purpose of this paper is to introduce the technology of Big Data storage, prospects of storage technologies, for example, the software DIRAC. The DIRAC is a software framework for distributed computing.

    The report considers popular storage technologies and lists their limitations. The main problems are the storage of large data, the lack of quality in the processing, scalability, the lack of rapid availability, the lack of implementation of intelligent data retrieval.

    Experimental computing tasks demand a wide range of requirements in terms of CPU usage, data access or memory consumption and unstable profile of resource use for a certain period. The DIRAC Data Management System (DMS), together with the DIRAC Storage Management System (SMS) provides the necessary functionality to execute and control all the activities related with data.

    Views (last year): 2.
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International Interdisciplinary Conference "Mathematics. Computing. Education"