And Digital Library Services Registries The OCKHAM Project And Digital Library Services Registries

History and Context of the OCKHAM Initiative Current Work OCKHAM Services OCKHAM Registry Future Directions

Four Goals: 1) Reference Model 2) New Services (including registry) 3) Adoption of Services / Registry 4) Dissemination and Community Building

Reference Model Service Provider Service Accepter DL Services Registry

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

Digital Library Services Registry (DLSR) DNS for Digital Library Services Distributed to promote extensibility and scalability Uses IESR Metadata Model Enables Machine-to-Machine Functionality

Emory ND root1 root2 root3 OSU VIEWS Va. Tech

O A I P M H

Service-based DL

Collection Service Agent administers owns provides access

Architecture Overview OCKHAM Registry Architecture Overview

Design Goals Broad compatibility with existing technologies: OAI, Z39.50, Http Modular design to allow extensibility Uses Open Source and Open Standards

Registry Architecture

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 Library Services

Put the pieces together

OCKHAM Future Expand the DLSR Community and Use Explore and build DLSR-aware tools and services Prototype semi-automated creation of DL’s

Further Information OCKHAM Website – http://ockham.org Martin Halbert, Emory – mhalber@emory.edu Jeremy Frumkin, Oregon State University – jeremy.frumkin@oregonstate.edu