History & numbers (109 words)

In 1999, it was obvious that CERN alone would never have the computing required to crunch the vast amounts of data from the LHC.

In 2001 we decided to combine the resources of computing sites across the world to store data and provide computing power.

From 2002-2005, CERN and collaborating institutes developed prototype equipment and techniques to make this ‘computing grid’ possible.

In 2006, the LHC Computing Grid became officially worldwide, as global computing centres started to connect to CERN.

Today, the Worldwide LHC Computing Grid is

  • 183 computing centres
  • 40 countries
  • 180 PB disk storage
  • 260,000 processing cores
  • 70TB stored at CERN alone


Print out/show excerpts from: https://espace.cern.ch/WLCG-document-repository/Presentations/Archive/2001/CERN-LHCC-2001-004_22FEB2001.pdf

The Grid Never Sleeps…. (130 words)

A computing grid is the most effective solution to the LHC data challenge, offering many advantages.

Computer centres are in multiple time-zones, so monitoring and expert support are available 24/7, 365 days/year (1)

WLCG is resilient - if a site has a problem, the grid can redistribute computing tasks to other sites so there is no interruption in the data processing. (2)

Full copies of data can be kept at different sites for safe-keeping, ensuring access for all scientists independent of geographical location. (3)

The system is highly flexible. We continually develop the system as more data is collected, improving performance and absorbing new computing technologies. (4)

Smaller sites can benefit from the new technologies that appear, and take advantage of global expertise to help train their own people. (5)

(1) 1008287_04-A5-at-72-dpi.jpg (2)(from http://cds.cern.ch/record/1286514) 1008159_08-A5-at-72-dpi.jpg (3) 1008285_01-A5-at-72-dpi.jpg (4) from http://cds.cern.ch/record/1425937 1202016_04-Icon.jpg (4) 1202016_06-Icon.jpg (5) 20110923_0102.JPG

Tiers & Networking

Strength in numbers…

The WLCG is split into layers, or ‘tiers’, with each providing a specific set of services.

Tier-0: The CERN Data Centre, is the beating heart of the WLCG, with all data passing through this central hub. It is responsible for the safe-keeping of all of the LHC data.

Tier-1: From tier-0, the data is passed on to 12 tier-1 sites, via fast optical-fibre links. As well as being responsible for the processing and storage of much data, it is the job of these large computer centres to distribute and manage the data for smaller, tier-2 sites.

Tier-2: Each tier-1 site is linked to a number of smaller tier-2 sites, which are typically universities and other scientific institutes. Today there are approximately 140 tier-2 sites and together they make up over half of the WLCG’s total computing power.


What has WLCG achieved?

(137 words)

Computing was an essential component in the discovery of the Higgs - without the WLCG, the LHC would have quickly drowned in its own data.

The speed and volume of processing was unprecedented; analysis of xxx billion collisions to find the xxx Higgs signals was successfully completed within weeks after the 2 year LHC running period ended. (1)

Another great achievement of WLCG is the successful involvement of so many countries, organisations and people with such diverse backgrounds. This immense collaboration has enabled sharing of knowledge, technology, training and ideas, transcending political and cultural boundaries. (2)

When the LHC re-opens in 2014, data rates will double. WLCG will be working hard to provide the processing power to enable discoveries of new phenomena hiding in the data. (3)

(1) D90_000487.jpg (1) _DSC0034_2.jpg (2) 2L%20-%20Overview.jpg 1207136_37-A5-at-72-dpi.jpg 1207136_93-A5-at-72-dpi.jpg http://cds.cern.ch/record/1459503 _MG_8389b.jpg (3) event-7.jpg (3) http://cds.cern.ch/record/1073733 0705032_01-A5-at-72-dpi.jpg

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