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

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

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

5. Reference Model
Service Provider
Service Accepter DL
Services
Registry

6. 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

7. Harvest-to-Query (H2Q)
OAI
Z39.50
SRU
SRW
OAI
OAI

8. 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

9. Emory ND
root1
root2
root3
OSU
VIEWS
Va. Tech

10. O A I P M H

11. Service-based DL

12. Collection
Service
Agent
administers
owns
provides
access

16. Architecture Overview
OCKHAM Registry
Architecture Overview

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

18. Registry Architecture

19. Data Layer Relational Db & OJB Synchronized
Database Interchangeability
Ease of development
Lucene
Fast indexing
“on the fly” indexing
Flexible query engine

20. Interface Layer Current Interfaces Struts powered J2ee interface
OAICat - OAI-PMH 2.0
Future Interfaces
SRU/W
Z39.50
Output Formats
Html
XML

21. Clients
Web browser
OAI-PMH
Z39.50
Any web enabled application.

22. 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

23. 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

24. 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

25. Put the pieces together

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

27. Further Information OCKHAM Website – http://ockham.org
Martin Halbert, Emory –
Jeremy Frumkin, Oregon State University –