2nd of July 2009 -Two weeks were needed to demonstrate that the largest particle accelerator in the world, the Large Hadron Collider (LHC), is fully ready to continue data taking later this year. After a small breakdown forced scientists to stop the Collider on 10 September 2008, researchers have begun testing it again. Under the name of STEP'09 (Scale Testing for the Experiment Programme '09), these tests have confirmed that the optical network needed by the LHC to transport and exchange data is fully prepared to begin working. The Scientific Information Centre (PIC), located at the UAB campus, supervised the tests for the Spanish Tier-1 centre and concluded with stable results and record performance levels. The LHD will begin functioning again later this year.
Universitat Autònoma de Barcelona, the 2nd of July 2009.
The fourteen days of testing involved the whole data transferring process: from detectors at the European Laboratory of Particle Physics (CERN) to thousands of physics around the world analysing data on the origins of our Universe. Records of all sorts were established: data taking throughput, data import and export rates between the various grid sites, as well as huge numbers of analysis, simulation and reprocessing jobs - the ATLAS experiment alone ran close to 1M analysis jobs and achieved 6GB/s of "grid traffic" sustained over long periods. To this effect, the specific LHC optical network which transports data between CERN and the 11 Tier-1 centres around the world, one of them PIC, has demonstrated both its performance and reliability capacities.
During the experiment programme STEP’09 massive scale testing was carried out of end-user analysis scenarios, including grid and application expert groups such as PIC, the Centre for Energetic, Environmental and Technological Research (CIEMAT), the Spanish National Research Council (CSIC), the Institute of High-Energy Physics of Barcelona (IFAE), and the Autonomous Universities of Barcelona and Madrid, the University of Barcelona, and the University of Santiago de Compostela.
Gonzalo Merino, researcher at CIEMAT and manager of the Tier-1 centre at PIC, defined STEP’09 testing as “a very valuable exercise since many of the experiment workflows have been tested simultaneously at unprecedented scale, well above the nominal values for LHC data taking. The Tier-1 at PIC has provided a very stable and reliable service at record breaking levels: exchanging up to 80 terabytes per day with other WLCG sites and processing data at more than 2 GBytes per second. This gives us confidence that the Spanish WLCG sites are ready for data taking”.
33 countries, 140 computer centres
The Worldwide LHC Computing Grid (WLCG) combines IT (Information Technologies) resources from over 140 data processing centres as a result of a joint collaboration between 33 countries. In order to present LHC experiments coherently to these centres, the Grid computing services are used, such as the EGEE project (Enabling Grids for E-sciencE) co-funded by the EU, and the OSG project (Open Science Grid) co-funded by the US.
Bob Jones, director of the EGEE project, remarked: "Such a significant achievement is also a valuable testament to the state of maturity of the EGEE infrastructure and its ability to interoperate with major grid infrastructures in other parts of the world. Ensuring that this level of service continues uninterrupted as we transition from EGEE to EGI (European Grid Infrastructure) is clearly essential to our users, including flagship communities such as high energy physics and LHC in particular." For this reason a close collaboration is essential between participants of each country in large international research projects and in the emerging National Grid Infrastructures (NGI) coordinated in Europe by EGI. In Spain, the Spanish Network of E-Science, funded by the Ministry for Science and Innovation, has begun to work on the country's own NGI. PIC and other WLCG centres in Spain are members of the Spanish Network of E-Science.
