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The OCKHAM Project. And Digital Library Services Registries. History and Context of the OCKHAM Initiative The funded NSF/NSDL Grant OCKHAM Services OCKHAM Registry Future OCKHAM. Four Goals:. 1) Reference Model. 2) New Services (including registry). 3) Adoption of Services / Registry.
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The OCKHAM Project And Digital Library Services Registries
History and Context of the OCKHAM Initiative • The funded NSF/NSDL Grant • OCKHAM Services • OCKHAM Registry • Future OCKHAM
Four Goals: 1) Reference Model 2) New Services (including registry) 3) Adoption of Services / Registry 4) Dissemination and Community Building
DL Services Registry Service Provider Service Accepter Reference Model
Initial OCKHAM Services 1) Digital Library Services Registry 4) Harvest-to-Query Service 2) Alerting Service 3) Browsing Service 5) Conversion Service 6) Cataloging Service 7) Pathfinding Service
Harvest-to-Query (H2Q) OAI Z39.50 SRU SRW OAI OAI
P2P Registry (aka Distributed Registry) • Digital Library Services Registry • DNS for Digital Library Services • Distributed to promote extensibility and scalability • Uses IESR Metadata Model • Enables Machine-to-Machine Functionality • Service-to-Service • Auto-discovery • Intrastructure
OCKHAM Registry Architecture Overview
Design Goals • Broad compatibility with existing technologies: OAI, Z39.50, Http • Modular design to allow extensibility
Data Layer Relational Db & OJB • Synchronized • Database Interchangeability • Ease of development Lucene • Fast indexing • “on the fly” indexing • Flexible query engine
Interface Layer Current Interfaces • Struts powered J2ee interface • OAICat - OAI-PMH 2.0 Future Interfaces • SRU/W • Z39.50 Output Formats • Html • XML
Clients • Web browser • OAI-PMH • Z39.50 • Any web enabled application.
Network Layer • JXTA provides low level network functionality • Peer identification and discovery • Transport layer • PeerManager provides modular application level functionality • Load Management • Client/Server Modules • Main Registry Modules • URL Server • Harvester Client
Using OAI For Propagating Data • A peer can query any other peer and receive an incremental update • Queries are based on the latest record modification date for the peer’s local copy of the set • Subsequent queries will use the new latest record modification date
Hierarchal Network Topology Topology Requirements • Data must propagate to all peers • Compensation for inherent instability of P2P networks • Scalable structure • Low overhead • DNS for Digital LibraryServices
OCKHAM Future • Expand the DLSR Community and Use • Explore and build DLSR-aware tools and services • Examine personal use of the DLSR • Continue to collaborate with IESR