LHC Computing Grid
The Worldwide LHC Computing Grid is an international collaborative project that consists of a grid-based computer network infrastructure connecting 140 computing centers in 35 countries. It has been designed by CERN to handle the significant volume of data produced by Large Hadron Collider (LHC) experiments.[1][2]
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[edit] Description
A design report was published in 2005.[3] It was announced to be ready for data on 3 October 2008.[4] A popular 2008 press article predicted "the internet could soon be made obsolete" by its technology.[5] CERN had to publish its own articles trying to clear up the confusion.[6] It incorporates both private fiber optic cable links and existing high-speed portions of the public Internet. At the end of 2010, the Grid consisted of some 200,000 processing cores and 150 petabytes of disk space, distributed across 34 countries.[7]
The data stream from the detectors provides approximately 300 GByte/s of data, which after filtering for "interesting events", results in a "raw data" stream of about 300 MByte/s. The CERN computer center, considered "Tier 0" of the LHC Computing Grid, has a dedicated 10 Gbit/s connection to the counting room.
The project was expected to generate 27 TB of raw data per day, plus 10 TB of “event summary data”, which represents the output of calculations done by the CPU farm at the CERN data center. This data is sent out from CERN to eleven Tier 1 academic institutions in Europe, Asia, and North America, via dedicated 10 Gbit/s links. This is called the LHC Optical Private Network.[8] More than 150 Tier 2 institutions are connected to the Tier 1 institutions by general-purpose national research and education networks.[9] The data produced by the LHC on all of its distributed computing grid is expected to add up to 10–15 PB of data each year.[10]In total, the four main detectors at the LHC produced 13 petabytes of data in 2010.[7]
The Tier 1 institutions receive specific subsets of the raw data, for which they serve as a backup repository for CERN. They also perform reprocessing when recalibration is necessary.[9] The primary configuration for the computers used in the grid is based on Scientific Linux.
Distributed computing resources for analysis by end-user physicists are provided by the Open Science Grid, Enabling Grids for E-sciencE,[9] and LHC@home projects.
[edit] See also
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Book: Large Hadron Collider |
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[edit] References
- ^ What is the Worldwide LHC Computing Grid?, CERN, January 2011, http://lcg.web.cern.ch/lcg/public/overview.htm, retrieved 2012-01-11
- ^ Welcome, CERN, January 2011, http://lcg.web.cern.ch/lcg/public/, retrieved 2012-01-11
- ^ LHC Computing Grid: Technical Design Report. The LCG TDR Editorial Board. 20 June 2005. ISBN 92-9083-253-3. http://cdsweb.cern.ch/record/840543/files/lhcc-2005-024.pdf. Retrieved 2 October 2011.
- ^ "LHC GridFest". CERN. 2008. http://lcg.web.cern.ch/LCG/lhcgridfest.
- ^ Jonathan Leake (6 April 2008). "Coming soon: superfast internet". The Times (London). http://www.timesonline.co.uk/tol/news/science/article3689881.ece. Retrieved 3 October 2011.
- ^ "The Grid: separating fact from fiction". CERN. May 2008. http://www.timesonline.co.uk/tol/news/science/article3689881.ece. Retrieved 3 October 2011. Adapted from an article originally published in Symmetry Breaking.
- ^ a b Geoff Brumfiel (19 January 2011). "High-energy physics: Down the petabyte highway". Nature 469: pp. 282–283. doi:10.1038/469282a. http://www.nature.com/news/2011/110119/full/469282a.html. Retrieved 2 October 2011.
- ^ "Network transfer architecture". CERN. http://lcg.web.cern.ch/LCG/public/data_transfer.htm. Retrieved 2 October 2011.
- ^ a b c final-draft-4-key[dead link]
- ^ Brodkin, Jon (28 April 2008). "Parallel Internet: Inside the Worldwide LHC computing grid". Techworld.com. http://www.techworld.com/mobility/features/index.cfm?featureid=4074&pn=2.
[edit] External links
- Official webpage The World Wide LHC Computer Grid
- "GridCafé". Educational web site. http://www.gridcafe.org/.
