GridPP3: NorthGrid tier-2 hardware and support at Sheffield

Lead Research Organisation: University of Sheffield
Department Name: Physics and Astronomy


'The Grid' is the next leap in computer interconnectivity. The Internet and the World Wide Web are increasingly an integral part of people's lives, helping the world share information and transfer data quickly and easily. In the same way as we now share files and facts over the global network of computers, in the future the Grid will let us share other things, such as processing power and storage space. The Grid is a practical solution to the problems of storing and processing the large quantities of data that will be produced by industry and the scientific communities over the next decade. Particle physicists are waiting for 2007 when a new particle accelerator opens in the world's largest particle physics laboratory, CERN. The Large Hadron Collider (LHC) will be the most powerful instrument ever built to investigate fundamental physics. Once this is fully functional the amount of data being produced will be massive. All this will be too much for one institution to handle so they need to share resources i.e. to use distributed computing. The Grid is built on the same Internet infrastructure as the web, but uses different tools. Middleware is one of these tools. In a stand alone computer the resources allocated to each job are managed by the operating system e.g. Windows, Linux, Unix, Mac OS X. Middleware is like the operating system of a Grid, allowing users to access resources without searching for them manually. GridPP has developed middleware for the Grid, in collaboration with other international projects. Due to GridPP's open source policy, the middleware can evolve and be improved by the people who use it. Distributed computing has been available to scientists for some time but, in general, the use of different sites has to be negotiated by each scientist individually. They need a separate account on each system and jobs have to be submitted and results collected back by hand. Current distributed computing means the user has a lot of work to do to get their results. This is where the idea of Grid computing comes in. Middleware lets users simply submit jobs to the Grid without having to know where the data is or where the jobs will run. The software can run the job where the data is, or move the data to where there is CPU power available. Using the Grid and middleware, all the user has to do is submit a job and pick up the results. Acting as the gatekeeper and matchmaker for the Grid, middleware monitors the Grid, decides where to send computing jobs, manages users, data and storage. It will check the identity of the user through the use of digital certificates. A digital certificate is a file stored securely on a user's computer which allows the Grid to correctly identify a user. The certificates are given to a user by the Certification Authority, with numerous steps to ensure the person applying is who they say they are. The middleware automatically extracts the users' identity from their digital certificate and uses this to log them in. This means users don't have to remember user names and passwords to log onto the Grid, they're automatically logged on using their Grid certificate. After this seamless identification process the middleware will find the most convenient and efficient places for the job to be run and organise efficient access to the relevant scientific data. It deals with authentication to the different sites being used, runs the jobs, keeps track of progress, lets the user know when the work is complete and transfers the result back.


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Description Support for ATLAS physcs analysis programme at CERN LHC
Exploitation Route Used to analyse data at ATLAS
Sectors Digital/Communication/Information Technologies (including Software)

Description ATLAS Upgrade collaboration 
Organisation European Organization for Nuclear Research (CERN)
Department ATLAS Collaboration
Country Switzerland 
Sector Academic/University 
PI Contribution The UK participates in the following upgrade projects: Tracker, L1 calorimeter trigger, L1 track trigger, High Level Trigger and Computing & Software Within the the tracker the UK has made significant contributions to the development of radiation hard sensors, readout electronics, module assembly and construction of local and global mechanical supports. UK physicists hold a number of international leadership roles within the Tracker Upgrade Collaboration, including the project leader. Within the L1 calorimeter trigger, the UK is responsible for the design, construction and commissioning of the eFEX and ROD boards. The UK is one of the main proponents of the L1 Track Trigger programme and is providing studies of the impact on the physics, designing the data flow and implementing within the strip readout. The UK provides expertise and leadership in a number of areas within the High Level Trigger, covering muon and electron signatures and global and tracking software. Within Computing & Software the UK provides expertise in developing the simulation and tracking software for high multiplicity environments and taking advantages of new computing architectures.
Collaborator Contribution The international ATLAS Upgrade programme consists of contributions from about 174 institutions (the UK is 15 of the 174). Our partners bring funding that makes the large undertaking of upgrading the ATLAS experiment possible. Our partners provide complementary expertise to the UK and take responsibility for other areas of the project.
Impact ~600 scientific papers and reports from 2010-present. The project brings together experts in many disciplines: Physics, mechanical engineering, electronic engineering, computing & software