> From anna@nesc.ac.uk Fri May 30 10:13:31 2003 > Message-Id: <200305300913.h4U9DPF7012247@zappa.nesc.ed.ac.uk> > From: AHM2003 - CyberChair > To: l.smith@epcc.ed.ac.uk > Cc: r.perrott@qub.ac.uk, anna@nesc.ac.uk > Subject: AHM2003 Abstract Submission Form Feedback > Date: Fri May 30 10:13:25 2003 BST > Reply-To: anna@nesc.ac.uk > X-Mailer: Python smtplib > X-Scanned-By: MIMEDefang 2.29 (www . roaringpenguin . com / mimedefang) > X-Spam-Checker-Version: SpamAssassin 2.50-cvs (1.162-2003-01-14-exp) > X-Spam-Status: No, hits=-99.6 required=5.0 > tests=BAYES_01,DATE_IN_PAST_06_12,INVALID_DATE,USER_IN_WHITELIST > version=2.50-cvs > X-Spam-Level: > X-Status: > X-Keywords: > X-UID: 1613 > > Dear Lorna, > > You have submitted the following data for the AHM2003 Conference: > > -=-=-=-=-= Beginning of submission data (step 1)=-=-=-=-=- > > > Contact Person: > Name: Lorna Smith > Address: > EPCC, > James Clark Maxwell Building, > The University of Edinburgh, > Kings Buildings, > Edinburgh, > EH9 3JZ > > Phone: +44 131 650 4980 > Fax: +44 131 650 6555 > Email: l.smith@epcc.ed.ac.uk > > Title: QCDGrid: A grid resource for Quantum Chromodynamics > > Author 1: > Name: James Perry > Affiliation: EPCC, The University of Edinburgh > > Author2: > Name: Andrew Jackson > Affiliation: EPCC, The University of Edinburgh > > Author3: > Name: Lorna Smith > Affiliation: EPCC, The University of Edinburgh > > Author4: > Name: Stephen Booth > Affiliation: EPCC, The University of Edinburgh > > Author is PC Member: No > > Main Fields: > 4. Science Application > 7. Data Integration > > > Abstract: > Quantum Chromodynamics (QCD) is an application area that requires access to > large supercomputing resources and generates huge amounts of raw data. UKQCD > is a group of geographically dispersed theoretical QCD scientists in the UK > that currently stores and requires access to around five terabytes of data, a > figure that is expected to grow dramatically as the collaborations purpose > built HPC system, QCDOC, comes on line in 2004. > > This data is stored on QCDGrid, a data grid currently composed of six storage > elements at four separate UK sites: Edinburgh, Liverpool, Swansea and RAL. > The QCDGrid software builds on the Globus toolkit (which provides the security > infrastructure and basic grid operations such as data transfer), to create a > robust multi-site data management system. This system has a central control > thread running on one of the storage elements which constantly scans the grid, > making sure that all of the storage elements are working and that all the > files are stored in at least two suitable locations. Hence when a new file is > added any storage node, it is rapidly replicated across the grid onto two or > more geographically separate sites. Similarly, when a storage element is lost > from the system unexpectedly, the data grid software will automatically > replicate the files that were held there on to the other storage nodes. In > this way, the QCDGrid has the ability to cope with the loss of an entire site > without losing any data. > > The software has been designed to allow users to access files easily and > efficiently. For example, it generally takes longer to transfer a file from > Swansea to Edinburgh than it would to transfer it from another machine at > Edinburgh. Therefore, when a user requests a file, the software will > automatically return a copy of the replica of that file which is nearest to > the user. Additionally, a user > can register interest in having a particular file stored on a particular > storage element, such as the one located physically closest to them. The grid > software will then take this request into account when deciding where to store > the file. > > Users can access files on the data grid directly, however to simplify the > procedure QCDGrid has a metadata catalogue, which stores data that describes > the characteristics of the raw data. This allows users to search and retrieve > files on the grid based on certain characteristics, without having to know the > file name or its physical location on the grid. The metadata is in the form > of XML documents, for which UKQCD have developed an XML schema that defines > the structure and content of this metadata in an extensible and scientifically > meaningful manner. > > Users can access the data grid through simple command line tools, or through > the QCD browser, which is based on the OGSA-DAI browser. > > Current work on the project is focussed on coupling the European Data Grid job > submission software to the data grid, to allow QCD scientists to submit jobs > to a range of computational resources across the country, with data being > added and retrieved from the datagrid in a seamless manner. > > QCDGrid is part of the GridPP project, a collaboration of Particle Physicists > and Computing Scientists from the UK and CERN, who are building a Grid for > Particle Physics. > > For further details see: > > http://www.epcc.ed.ac.uk/computing/research_activities/grid/qcdgrid/ > > and: > > http://www.gridpp.ac.uk > > Keywords: DataGrid, Quantum Chromodynamics, Globus, GridPP, European DataGrid > > > > Remarks: > I would like to submit this for a presentation in a parallel session. > > -=-=-=-=-=-= End of abstract submission data =-=-=-=-=-=- > > > IMPORTANT: To submit your paper you should revisit the > submission site at http://cyberchair.nesc.ac.uk/AHM2003/, go to > step 2 and at the appropriate places fill in the following: > > You will then be able to upload your paper. > > > If you have questions about this message, please contact Anna Kenway > (anna@nesc.ac.uk). > > --- End of this message --- > > -- Dr Lorna Smith l.smith@epcc.ed.ac.uk EPCC, Edinburgh University