1. Eine Einführung ins Grid Andreas Gellrich IT Training DESY Hamburg 28.10.2008

2. Andreas GellrichDESY, 28.10.2008 1 The Power Grid

3. Andreas GellrichDESY, 28.10.2008 2 The Grid Dream GRIDMIDDLEWAREGRIDMIDDLEWARE Visualizing Supercomputer, PC-Cluster Data Storage, Sensors, Experiments Internet, Networks Desktop Mobile Access

4. Andreas GellrichDESY, 28.10.2008 3 Grid Computing Grid Computing is about virtualization of global resources. It is about transparent access to globally distributed resources such as data and compute cycles A Grid infrastructure consists of services to access resources and (of course) of the resources itself  Opposite to distributed computing, Grid resources are not centrally controlled  Hence it is mandatory to use standard, open, general-purpose protocols and interfaces  A Grid must deliver nontrivial qualities of services In general Grid infrastructures are generic; without any dependencies of the applications / experiments

5. Andreas GellrichDESY, 28.10.2008 4 Grid Types Data Grids: Provisioning of transparent access to data which can be physically distributed within Virtual Organizations (VO) Computational Grids: allow for large-scale compute resource sharing within Virtual Organizations (VO) (Information Grids): Provisioning of information and data exchange, using well defined standards and web services Jobs are transient ; data is persistent.

6. Andreas GellrichDESY, 28.10.2008 5 Grid Building Blocks A Virtual Organization (VO) is a dynamic collection of individuals, institutions, and resources which is defined by certain sharing rules.  A VO represents a collaboration  Users authenticate with personal certificates (Authentication)  Users are members of a certain VO (Authorization)  Certificates are issued by a Certification Authority (CA) Grid Infrastructure  Core Services (mandatory per VO)  VO Membership Services  Grid Information Services  Workload Management System  Resources (brought in by partners (Grid sites))

7. Andreas GellrichDESY, 28.10.2008 6 Overview 02-Feb-2007

8. Andreas GellrichDESY, 28.10.2008 7 Site3 Site2 output UI LFC WN SE GRIS CE GRIS BDII JDL WMS Batch LFC VOMS Grid Services grid-mapfile Site1 ssh usercert.pem / userkey.pem certs GIIS store world Services View R-GMA VO exclusive SW

9. Andreas GellrichDESY, 28.10.2008 8 VO & Grid Resources @ DESY VOs hosted at DESY: Global: ‘hone’, ‘ilc’, (‘xfel.eu’), ‘zeus’ Regional: ‘calice’, ‘ildg’ Local: ‘desy’, ‘hermes’, ‘icecube’ VOs supported at DESY: Global: ‘atlas’, ‘biomed’, ‘cms’, ‘lhcb’, ‘dteam’, ‘ops’ Regional: ‘dech’, ‘xray.vo.egee-eu.org’ Grid Computing Resources at DESY: (CE) grid-ce3.desy.de 1262 slots @ 261 hosts (all) hera-ce0.desy.de 314 slots @ 90 hosts (‘hone’, ‘hermes’, ‘zeus’) Grid Storage Resources at DESY: (SE) [srm-dcache.desy.de] O(50 TB) w/ tape backend Dcache-se-desy.desy.de O(50 TB) w/ tape backend dcache-se-atlas.desy.de O(200 TB) w/ tape backend dcache-se-cms.desy.de O(200 TB) w/ tape backend

10. Andreas GellrichDESY, 28.10.2008 9 Operations View output UI LFC WN GRIS SE GRIS CE BDII JDL WMS Torque/Maui LFC VOMS Grid Services grid-mapfile DESY-HH ssh usercert.pem / userkey.pem certs GIIS store world R-GMA VO exclusive SW

11. Andreas GellrichDESY, 28.10.2008 10 jobs are transient data is persistent

12. Andreas GellrichDESY, 28.10.2008 11 The LHC Computing Model Tier2 Centre ~1 TIPS Online System Offline Farm ~20 TIPS CERN Computer Centre >20 TIPS GridKa Regional Centre US Regional Centre French Regional Centre Italian Regional Centre Institute Institute ~0.25TIPS Workstations ~100 MBytes/sec 100 - 1000 Mbits/sec One bunch crossing per 25 ns 100 triggers per second Each event is ~1 Mbyte Physicists work on analysis “channels” Each institute has ~10 physicists working on one or more channels Data for these channels should be cached by the institute server Physics data cache ~PBytes/sec ~ Gbits/sec or Air Freight Tier2 Centre ~1 TIPS ~Gbits/sec Tier 0 Tier 1 Tier 3 1 TIPS = 25,000 SpecInt95 PC (1999) = ~15 SpecInt95 DESY ~1 TIPS Tier 2