Peter Kunszt CERN Peter.Kunszt@cern.ch EU DataGrid WP2 Manager

1. EU DataGrid Data Management Services Peter KunsztCERNPeter.Kunszt@cern.ch EU DataGrid WP2 Manager

2. Talk Outline • Introdution to EU DataGrid workpackage 2 • WP2 Service Design and Interactions • Replication Services • Spitfire • Security • Conclusions and outlook WP2 Members Diana Bosio, James Casey, Akos Frohner, Leanne Guy, Peter Kunszt, Erwin Laure, Levi Lucio, Heinz Stockinger, Kurt Stockinger - CERN Giuseppe Andronico, Federico DiCarlo, Andrea Domenici, Flavia Donno, Livio Salconi – INFN William Bell, David Cameron, Gavin McCance, Paul Millar, Caitriona Nicholson – PPARC, University of Glasgow Joni Hahkala, Niklas Karlsson, Ville Nenonen, Mika Silander, Marko Niinimäki – Helsinki Institute of Physics Olle Mulmo, Gian Luca Volpato – Swedish Research Council

3. EU DataGrid Project Objectives • DataGrid is a project funded by European Union whose objective is to exploit and build the next generation computing infrastructure providing intensive computation and analysis of shared large-scale databases. • Enable data intensive sciences by providing world wide Grid test beds to large distributed scientific organisations ( “Virtual Organisations, VO”) • Start ( Kick off ) : Jan 1, 2001 End : Dec 31, 2003 • Applications/End Users Communities : HEP, Earth Observation, Biology • Specific Project Objetives: • Middleware for fabric & grid management • Large scale testbed • Production quality demonstrations • To collaborate with and complement other European and US projects • Contribute to Open Standards and international bodies ( GGF, Industry&Research forum)

4. DataGrid Main Partners • CERN – International (Switzerland/France) • CNRS - France • ESA/ESRIN – International (Italy) • INFN - Italy • NIKHEF – The Netherlands • PPARC - UK

5. Assistant Partners • Industrial Partners • Datamat (Italy) • IBM-UK (UK) • CS-SI (France) • 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

6. Project Schedule • Project started on 1/Jan/2001 • TestBed 0 (early 2001) International test bed 0 infrastructure deployed Globus 1 only - no EDG middleware • Successful Project Review by EU: March 2002 • TestBed 1 ( 2002 ) • Successful 2nd Project Review by EU: February 2003 • TestBed 2 (Now) Some complete re-writes of components. Builds on TestBed 1 experience. • TestBed 3 (Oktober 2003) • Project stops on 31/Dec/2003, maybe a couple of months extension to wrap up and document results (no additional funding)

7. EDG Highlights • All EU deliverables (40, >2000 pages) submitted • in time for the review according to the contract technical annex • First test bed delivered with real production demos • All deliverables (code & documents) available via www.edg.org • http://cern.ch/eu-datagrid/Deliverables/default.htm • requirements, surveys, architecture, design, procedures, testbed analysis etc. • Project re-orientation last year in August: From R&D Testbed to ‘production grid’

8. Working Areas • The DataGrid project is divided in 12 Work Packages distributed in four Working Areas Applications Middleware Testbed Management Infrastructure

9. Work Packages WP1: Work Load Management System WP2: Data Management WP3: Grid Monitoring / Grid Information Systems WP4: Fabric Management WP5: Storage Element WP6: Testbed and demonstrators WP7: Network Monitoring WP8: High Energy Physics Applications WP9: Earth Observation WP10: Biology WP11: Dissemination WP12: Management

10. Trying hard to have a real GRID.. • Testbed 0 : • Grid technology was not mature enough • Configuration and deployment issues • Stability problems • Obscure errors • Project reorientation: Stability, Stability, Stability – TB 1 • TB1 revealed a set of design bugs in Globus • GASS Cache issue – fixed by Condor (rewritten) • MyProxy issues – could never be used • MDS did not scale – had to set up fake local info system • Reingeneering of essential components – TB 2 • New resource broker • R-GMA instead of MDS as info system • Concrete Support channels (VDT) • New configuration tool LCFG-ng (from U of Edinburgh!)

11. Grid middleware architecture hourglass Current Grid architectural functional blocks: Specific application layer CMS ATLAS CMS LHCb Earth Observation and Biomed Common application layer HEP Application Services (LCG) EU DataGrid middleware High Level Grid Services GLOBUS 2.2 Basic Grid Services OS, Storage & Network services

12. EU DataGrid WP2Data Management Work Package Responsible for • Transparent data location and secure access • Wide-area replication • Data access optimization • Metadata access NOTresponsible for (but it has to be done) • Data storage (WP5) • Proper Relational Database bindings (Spitfire) • Remote I/O (GFAL) • Security infrastructure (VOMS)

13. WP2 Service Paradigms • Choice of technology: • Java-based servers using Web Services • Tomcat, Oracle 9iAS, soon WebSphere • Interface definitions in WSDL • Client stubs for many languages (Java, C, C++) • Axis, gSOAP • Persistent service data in Relational Databases • MySQL, Oracle, soon DB2 • Modularity • Modular service design for pluggability and extensibility • No vendor specific lock-ins • Evolvable • Easy adaptation to evolving standards (OGSA, WSDL 1.2) • Largely independent of underlying OS, RDBMS – works on Windows too!

14. Replication Services: Basic Functionality Each file has a unique Grid ID. Locations corresponding to the GUID are kept in the Replica Location Service. Users may assign aliases to the GUIDs. These are kept in the Replica Metadata Catalog. Files have replicas stored at many Grid sites on Storage Elements. Replica Metadata Catalog Replica Location Service Replica Manager The Replica Manager provides atomicity for file operations, assuring consistency of SE and catalog contents. Storage Element Storage Element

15. Higher Level Replication Services The Replica Subscription Service issues Replication commands automatically, based on a set of subscription rules defined by the user. Hooks for user-defined pre- and post-processing for replication operations are available. Replica Subscription Service The Replica Manager may call on the Replica Optimization service to find the best replica among many based on network and SE monitoring. Replica Metadata Catalog Replica Location Service Replica Manager Replica Optimization Service Storage Element Storage Element SE Monitor Network Monitor

16. Interactions with other Grid components Virtual Organization Membership Service User Interface or Worker Node Resource Broker Replica Subscription Service Information Service Replica Metadata Catalog Replica Location Service Replica Manager Replica Optimization Service Applications and users interface to data through the Replica Manager either directly or through the Resource Broker. Management calls should never go directly to the SE. Storage Element Storage Element SE Monitor Network Monitor

17. Replication Services Status • Current Status • All components are deployed right now – except for the RSS • Initial tests show that expected performance can be met • Need proper testing in a ‘real user environment’ – EDG2; LCG1 • Features for next release • Currently Worker Nodes need outbound connectivity – Replica Manager Service needed. Needs proper security delegation mechanism. • Logical collections support • Service-level authorization • GUI

18. Spitfire: Grid-enabling RDBMS • Capabilities: • Simple Grid enabled front end to any type of local or remote RDBMS through secure SOAP-RPC • Sample generic RDBMS methods may easily be customized with little additional development, providing WSDL interfaces • Browser integration • GSI authentication • Local authorization mechanism • Status: current version 2.1 • Used by EU DataGrid Earth Observation and Biomedical applications. • Next Step: OGSA-DAI interface

19. Spitfire added value : Security • Grid security • TrustManager deals with GSI proxy certificates • Support for VOMS certificate extensions • Secure java, c/c++, perl clients • Local Authorization • Mapping through Gridmap file supported • Fine grained authorization hooks : a mapping service is provided to map VOMS extensions (group, role, capability) to DB roles that depending on the DB may be row-level authorization mechanisms (GRANT/DENY). • Installation kit • Easy installation and configuration of all security options

20. Spitfire customization • Spitfire started as a ‘proof of technology’ for Web Services and java. • Customizable into specific services dealing with persistent data • All WP2 services are in this sense ‘Spitfire’ services (see later) • Test platform for latest available codebase • Gained experience with WSDL, JNDI, Tomcat, Axis, gSOAP • Next things to try : JBOSS (for JMS, JMX) • Experimental add-ons • Secure browser using JSP (proxy certificates for mozilla, netscape, ie..) • Distributed query agent drop-in • Todo: OGSA-DAI interface as far as possible

21. RLS Architecture (evolved!) A hierarchical RLS topology: LRCs update RLIs, RLIs may forward information RLI RLI RLI RLI RLI RLI RLI RLI LRC LRC LRC LRC LRC sending updates to all Tier 1 RLIs RLIs indexing over the full namespace (all LRCs are indexed) receiving updates directly RLI receiving updates from other RLIs

22. EDG Grid Catalogs (1/2) • Replica Location Service (RLS) • Local Replica Catalog (LRC) • Stores GUID to Physical File Name (PFN) mappings • Stores attributes on PFNs • Local Replica Catalogs in Grid : One per Storage Element (per VO) • Tested to 1.5M entries • Replica Location Index (RLI) • Allow fast lookup of which sites store GUID -> PFN mappings for a given GUID • Replica Location Indices in the Grid :Normally one per Site (per VO), which indexes all LRCs in the Grid • Being deployed as part of EDG 2.1 in July • In the process of integration into other components • Tested to 10M entries in an RLI

23. EDG Grid Catalogs (2/2) • Replica Metadata Catalog (RMC) • Stores Logical File Name (LFN) to GUID mappings – user-defined aliases • Stores attributes on LFNs and GUIDs • One logical Replica Metadata Catalog in Grid (per VO) • Single point of synchronization – current assumption in EDG model • bottleneck ? - move to replicated distributed database • No Application Metadata Catalog provided – see Spitfire • But Replica Metadata Catalog has support for small level of application metadata – O(10) • RMC usage not as well understood as Replica Location Service • Architectural changes likely • Use cases required

24. CNAF Storage Element Local Replica Catalog Replica Location Index Local Replica Catalog Replica Location Index Storage Element IN2P3 Typical Location of Services in LCG-1 CERN Storage Element Replica Metadata Catalog Local Replica Catalog Replica Location Index Local Replica Catalog Replica Location Index Storage Element Storage Element RAL

25. Catalog Implementation Details • Catalogs implemented in Java as Web Services, and hosted in a J2EE application server • Uses Tomcat4 or Oracle 9iAS for application server • Uses Jakarta Axis for Web Services container • Java and C++ client APIs currently provided using Jakarta Axis (Java) and gSoap (C++) • Catalog data stored in a Relational Database • Runs with either Oracle 9i or MySQL • Catalog APIs exposed as a Web Service using WSDL • Easy to write a new client if we don’t support your language right now • Vendor neutral approach taken to allow different deployment options

26. Quality of Service • Quality of Service depends upon both the server software and architecture used as well as the software components deployed on it • Features required for high Quality of Service • High Availability • Manageability • Monitoring • Backup and Recovery with defined Service Level Agreements • Approach • Use vendor solutions for availability and manageability where available • Use common IT-DB solutions for monitoring and recovery • Components architected to allow easy deployment in high-availability environment • A variety of solutions with different characteristics are possible

27. Tradeoffs in different solutions Clustered Oracle 9i/9iAS Clustered Oracle 9i/Tomcat Availability Single Instance MySQL/Tomcat Single Instance Oracle 9i/9iAS Manageability

28. System Architecture – High Availability • Standard n-tier architecture • Front end application layer load-balancer • Oracle 9iAS Web Cache • Cluster of stateless application servers • Oracle 9iAS J2EE container • Clustered database nodes • Oracle 9i/RAC • Shared SAN storage • Fibre Channel storage

29. Security: Infrastructure for Java-based Web Services • Trust Manager • Mutual client-server authentication using GSI (ie PKI X509 certificates) for all WP2 services • Supports everything transported over SSL • Authorization Manager • Supports coarse grained authorization: Mapping user->role->attribute • Fine grained authorization through policies, role and attribute maps • Web-based Admin interface for managing the authorization policies and tables • Status: • Fully implemented, authentication is enabled on the service level • Delegation implementation needs to be finished • Authorization needs more integration, waiting for deployment of VOMS

30. Conclusions and outlook • Re-focus on production has been a good but painful choice • from hype to understanding the implications of wanting to run a production Grid • reengineering of several components was necessary • however, the project was not well prepared for this change – the timelines had to be constantly revised in the last year • The second generation Data Management services have been designed and implemented based on the Web Service paradigm • Flexible, extensible service framework • Deployment choices : robust, highly available commercial products supported (eg. Oracle) as well as open-source (MySQL, Tomcat) • First experiences with these services show that their performance meets the expectations • Real-life usage will show its strengths and weaknesses on the LCG-1 and EDG2.0 testbeds during the rest of this year. • Proceed with standardization efforts: DAI, RLS • Carry over the experience into the next project : EGEE