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EGEE Catalogs Peter Kunszt EGEE Data Management Middleware http://cern.ch/egee-jra1 Service Grids NeSC, 22-23 July 2004 EGEE is a project funded by the European Union under contract IST-2003-508833
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Service Grids – NeSC, July 22-23, 2004 - 2 High-level strategy for middleware EGEE Middleware – To re-engineer generic middleware packages Incorporating experience from EDG, VDT, LCG, AliEn (product from CERN Alice experiment) and others Architected for scale and performance requirements of LCG and other applications EGEE design team formed early to develop architecture Architecture: https://edms.cern.ch/document/476451https://edms.cern.ch/document/476451 Fast prototyping approach Short update cycles to give applications the chance to influence and give feedback
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Service Grids – NeSC, July 22-23, 2004 - 3 Guiding principles Lightweight (existing) services Easily and quickly deployable Re-use as much as possible Interoperability Allow for multiple implementations Resilience and Fault Tolerance Service oriented approach Follow WSRF standardization No mature WSRF implementations exist to date, hence: start with plain WS – WSRF compliance is not an immediate goal Aim for WS-I compliance Co-existence with deployed infrastructure Co-existence (and convergence) with existing grid infrastructures (e.g. LCG2) are essential for the EGEE Grid service EDGVDT... LCG EGEE...AliEn
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Service Grids – NeSC, July 22-23, 2004 - 4 High-level functional decomposition Starting point was the ARDA roadmap document Focus is upon interfaces that can be composed into useful services
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Service Grids – NeSC, July 22-23, 2004 - 5 EGEE Data functional interfaces File Catalog Management of the logical namespace Replica Catalog Tracking of file replicas Metadata Catalog Application specific metadata In particular, metadata used to select logical files Combined Catalog Added functionality by orchestration of the 3 catalogs (providing transaction safety) Storage Element Where the files get stored SRM interface (see GGF GSM-WG) Manage a Storage Resource Space reservation Put and retrieve files using various protocols Posix-like File I/O Most posix-compliant feature support Abstraction over existing MSS IO mechanisms Data Management: File Transfer Service Reliable transfer of files between two sites File Placement Service Transfer and register files Orchestrate File Transfer and Data Catalog services Data Scheduling Service Event-based data transfer, using File Placement Service
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Service Grids – NeSC, July 22-23, 2004 - 6 Services: EGEE Catalogs File Catalog Management of the logical file namespace Replica Catalog Tracking of file replicas Metadata Catalog Application specific metadata; in particular, metadata used to select logical files Combined Catalog Added functionality by orchestration of the 3 catalogs (providing transaction safety)
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Service Grids – NeSC, July 22-23, 2004 - 7 File Catalog Metadata Catalog Replica Catalog Files and Catalogs LFNGUID Master SURL SURL Metadata
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Service Grids – NeSC, July 22-23, 2004 - 8 Services: EGEE Catalogs SOA: WS-I Implementation status: prototype
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Service Grids – NeSC, July 22-23, 2004 - 9 Service Operations File Catalog operations Directory operations Directory permissions Symbolic links List, find +Bulk ops (upload) Replica Catalog operations GUID mappings to SURLs ACLs File ‘stat’ like metadata +Bulk ops (upload, delete) Metadata Catalog operations Query, returning list of LFN/GUID Set metadata based on LFN/GUID Query metadata of LFN/GUID Combined interface List based on LFN (including replicas, metadata) Add entries just based on LFN (auto entry of GUID, SURL) Permissions based on LFNs http://cern.ch/pkunszt/catalogs/
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Service Grids – NeSC, July 22-23, 2004 - 10 What do you use to build your service? (i.e. How ‘standard’ is your service?) Widely Implemented Standard Specification (1pt) All services are described through WSDL, WS-I compliant (nontrivial!) X509 extensions used for authorization (VOMS) Implemented draft Spec (2pt) GSS/GSI for delegation Implemented draft specification (3pt) -- Implemented proposal (4pt) -- Non-implemented proposal (5pt) -- Concept (6pt) -- TOTAL: 4 Will use: messaging (JMS) first (+?), WS-Transactions, WS- Notification when they are available with lower rankings Security: Delegation portType (proposal) (+4?)
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Service Grids – NeSC, July 22-23, 2004 - 11 Service Dependencies What else does your service depend on (i.e. external dependencies)? RDBMS: need a JNDI connector. Can be anything beneath that, in principle. Implementation currently exists for Oracle, MySQL. Logging: log4j What does your implementation depend on? Tomcat 4 or 5 Java 1.4 Axis 1.1 Security libs GSI (using CoG + GSI security libs)
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Service Grids – NeSC, July 22-23, 2004 - 12 AAA & Security What authentication mechanism do you use? https: SSL/TLS / TrustManager + CoG What authorisation mechanism do you use? GSI Delegation -- Working on Delegation portType VOMS/AuthzManager Work ongoing on restricted delegation What accounting mechanism do you use? Logging, RGMA (see Abdeslem’s talk) Does service interaction need to be encrypted? No. Still waiting on detailed req’s from users whether they really need this If these are not used now, will they be in the future? Plugin-based extensibility planned. GSI over https used today. Extensions should talk anything that people need (WS-Security in particular)
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Service Grids – NeSC, July 22-23, 2004 - 13 Exploiting the Service Architecture What features from your ‘plumbing’ do you use in your service? Factory port : no Factory pattern : no Logging : yes Event notification : not yet Meta-data : yes Registry discovery/advertisement : yes Other OGSI/WSRF/WS/WS-GAF characteristics? No. but interested in –Messaging –Distributed Transactions, Sessions –Notifications and Eventing
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Service Grids – NeSC, July 22-23, 2004 - 14 Service Activity Multiple interaction or single user? multiple Throughput (1/per day or 100/per second?) Many per second. Typical data volume moved in Lots of small simultaneous single operations Bulk operations with O(>10000) entries, up to O(10 6 ) Typical data volume moved out Lots of small single ops (queries for ACL, lookups) Bulk listings used by scheduler
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Service Grids – NeSC, July 22-23, 2004 - 15 Service Failure Required Reliability Support for many bulk operation failure policies Fail on any Try as many as possible [implies Policy management] [implies notification for asynch ops] Atomic operation failures ‘straightforward’ Required Persistence State persistence not required, try to be atomic Required Availability Deployment choice.
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Service Grids – NeSC, July 22-23, 2004 - 16 Required Service Management Remote access to: Performance Progress Diagnostic and repair interfaces
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