Grid Projects: EU DataGrid and LHC Computing Grid Oxana Smirnova Lund University October 29, 2003, Košice

Outlook Precursors: attempts to meet tasks of HEP computing EDG: the first global Grid development project LCG: deploy computing environment for LHC experiments

Characteristics of HEP computing Eventindependence Event independence  Data from each collision is processed independently: trivial parallelism  Mass of independent problems with no information exchange Massivedatastorage Massive data storage  Modest event size: 1 – 10 MB (not ALICE though)  Total is very large – Petabytes for each experiment. Mostlyreadonly Mostly read only  Data never changed after recording to tertiary storage  But is read often! A tape is mounted at CERN every second! Resilience rather than ultimate reliability  Individual components should not bring down the whole system  Reschedule jobs on failed equipment Modestfloatingpointneeds Modest floating point needs  HEP computations involve decision making rather than calculation

Department    Desktop CERN – Tier 0 MONARC report: Tier 1 FNAL RAL IN2P3 622 Mbps 2.5 Gbps 622 Mbps 155 mbps Tier2 Lab a Uni. b Lab c Uni. n MONARC: hierarchical regional centres model

EU Datagrid project In certain aspects was initiated as a MONARC follow- up, introducing the Grid technologies Started on January 1, 2001, to deliver by end 2003  Aim: to develop a Grid middleware suitable for High Energy physics, Earth Observation, biomedical applications and live demonstrations  9.8 MEuros EU funding over 3 years  Development based on existing tools, e.g., Globus, LCFG, GDMP etc Maintains development and applications testbeds, which include several sites across the Europe

EDG overview : Main partners CERN – International (Switzerland/France) CNRS – France ESA/ESRIN – International (Italy) INFN – Italy NIKHEF – The Netherlands PPARC – UK Slide by EU DatGrid

Research and Academic Institutes CESNET (Czech Republic) Commissariat à l'énergie atomique (CEA) – France Computer and Automation Research Institute, Hungarian Academy of Sciences (MTA SZTAKI) Consiglio Nazionale delle Ricerche (Italy) Helsinki Institute of Physics – Finland Institut de Fisica d'Altes Energies (IFAE) - Spain Istituto Trentino di Cultura (IRST) – Italy Konrad-Zuse-Zentrum für Informationstechnik Berlin - Germany Royal Netherlands Meteorological Institute (KNMI) Ruprecht-Karls-Universität Heidelberg - Germany Stichting Academisch Rekencentrum Amsterdam (SARA) – Netherlands Swedish Research Council - Sweden EDG overview : Assistant Partners Industrial Partners Datamat (Italy) IBM-UK (UK) CS-SI (France) Slide by EU DatGrid

EDG work-packages  WP1: Work Load Management System  WP2: Data Management  WP3: Grid Monitoring / Grid Information Systems  WP4: Fabric Management  WP5: Storage Element, MSS support  WP6: Testbed and demonstrators  WP7: Network Monitoring  WP8: High Energy Physics Applications  WP9: Earth Observation  WP10: Biology  WP11: Dissemination  WP12: Management

Simplified Grid deployment approach Homogeneous structure  All the sites must run with the same OS and kernel (Linux, RedHat7.3)  Recommended central installation via LCFG service (installs entire machine from scratch on each reboot)  Exceptions are possible, but not supported Invasive installation  Requires massive existing cluster re-configuration  Needs to be installed on every compute node

Basic EDG services Workload management  Resource Broker (RB) and Job Submission Service (JSS)  Logging and Bookkeeping Service (L&B)  Information Index (II)  User Interface (UI) Data management  Replica Location Service (RLS)  Replica Metadata Catalog (RMC)  Replica Optimization Service (ROS) Information and monitoring service  Relational Grid Monitoring Architecture (R-GMA) Fabric management Mass storage management Virtual Organization management

Typical EDG site composition Site-specific: User Interface (UI) Computing Element or Service (CE)  Gatekeeper (GK)  Worker Nodes (WN) do have client APIs for accessing EDG services and information Storage Element (SE) Monitoring Node (MON)  R-GMA servlets for the site  ROS Common: Resource Broker (RB) RLS  Local Replica Catalog (LRC)  RMC Information Catalog (IC)

Organization of user access Users must have valid personal Globus-style certificates  Group or anonymous certificates are not allowed  Certificate Issuing Authority (CA) must be endorsed by the EDG Security Group  If there is no approved CA in your country/region, France catches all Users must belong to one of the accepted Virtual Organizations (VO)  LHC experiments, biomedical and Earth Observation applications, and some EDG teams  VO lists are managed by experiments/teams representatives  Users can belong to several VOs  Users with identical names or a user with several certificates can not belong to a same VO  Local system administrators still have a full control To “log into the Grid”, users make use of the private certificate to issue a public proxy Grid sites accept requests only from users whose certificates are signed by CAs that a site accepts

EDG applications testbed EDG is committed to create a stable testbed to be used by applications for real tasks  This started to materialize in August 2002…  …and coincided with the ATLAS DC1  CMS joined in December  ALICE, LHCb – smaller scale tests At the moment (October 2003) consists of ca. 15 sites in 8 countries Most sites are installed from scratch using the EDG tools (require/install RedHat 7.3)  Some have installations on the top of existing resources  A lightweight EDG installation is available Central element: the Resource Broker (RB), distributes jobs between the resources  Most often, a single RB is used  Some tests used RBs “attached” to User Interfaces  In future, may be an RB per Virtual Organization (VO) or/and per user ?

EDG Applications Testbed snapshot

Basic EDG functionality as of today UI CASTOR RLS CE RB do rfcp rfcp replicate RM jdl +R-GMA NFS RSL Output RM Input Output

EDG status The EDG1 was not a very satisfactory prototype  Highly unstable behavior  Somewhat late deployment  Many missing features and functionalities The EDG2 is released and deployed for applications on October 20, 2003  Many services have been re-written since EDG1  Some functionality have been added, but some have been lost  Stability is still the issue, esp. the Information System performance  Little has been done to streamline applications environment deployment  No production-scale tasks have been shown to perform reliably yet No development will be done beyond this point  Bug fixing will continue for a while  Some “re-engineering” is expected to be done by the next EU-sponsored project – EGEE

The future: LCG LCG  LHC Computing Grid Goal: to deploy an adequate information and computational infrastructure for the LHC experiments Means of achieving: using the modern distributed computing and data analysis tools and utilities – The Grid Resources: large computing centers around the World as the basic elements  Research institutes, laboratories and universities are also members of the data analysis chain  No need to concentrate the computing power at CERN

LCG Timeline September 2001: the project is approved by the CERN Council Duration: 2002 to 2008  Phase 1: prototyping, testing  Phase 2: deployment of the LHC computing infrastructure2 November 2003: a functioning LCG-1 prototype (a criterion: 30 consecutive days of non-stop operation); includes 10 regional centers May 2004: research lab and institutes are joining with their resources December 2004: LCG-3, 50% of expected by 2007 performance IX/ Phase 1 Phase 2 XI/03V/04XII/04

LCG organization Financing:  CERN and other states participating in LHC projects  Business partners  LHC experiments  National research foundations and computing centers  Projects financed my EU and other international funds Structure:  Applications  CERN fabric  Grid technology  Grid deployment FOR MORE INFO:

First priority: LCG-1 Computing clusterNetwork resourcesData storage Operating systemLocal schedulerFile system User accessSecurity Data transfer Information schema Global schedulerData managementInformation system User interfaces Applications Major components and levels: Hardware System software Passive services Active services High level services Closed system (?) HPSS, CASTOR… RedHat Linux NFS, … PBS, Condor, LSF,… VDT (Globus, GLUE) EU DataGrid LCG, experiments

grid for a physics study group grid for a regional group Tier2 Lab a Uni a Lab c Uni n Lab m Lab b Uni b Uni y Uni x Tier3 physics department    Desktop Germany Tier 1 USA UK France Italy Taiwan CERN Tier 1 Japan The LHC Computing Centre CERN Tier 0 LHC Grid: what became of the MONARC hierarchy

LCG status Grid component: almost entirely the EDG solution  Major difference: LCG-1 still has the “old” MDS for the information system  Deployed at the LCG testbed, non-overlapping with the EDG in general, includes non-EU countries like US, Russia or Taiwan  More stable so far than EDG (for MDS?..)  Little or no Grid development  In future, may consider alternative Grid solutions, e.g., the AliEn (though unlikely)  Grid Technology area is on the verge of being dismissed, as LCG will not be doing Grid development LHC Applications component:  A lot of very serious development  Many areas are covered, from generators to Geant4 to data management etc  Unfortunately, has little interaction and co-operation with Grid developers

LCG-1 Testbed

Summary Initiated by CERN, EDG came as the first global Grid R&D project aiming at deploying working services Sailing in uncharted waters, EDG ultimately provided a set of services, allowing to construct a Grid infrastructure Perhaps the most notable EDG achievement is introduction of authentication and authorization standards, now recognized worldwide LCG took a bold decision to deploy EDG as their Grid component for the LCG-1 release The Grid development does not stop with EDG: LCG is open for new solutions, with a strong preference towards OGSA