Distributed Digital Library Service Registry

The Ockham Service Registry

Support

• NSF / NSDL• DLF• Ockham collaborators

– Emory– Notre Dame– Virginia Tech– Oregon State

Why a Registry?

Just-in-time (post) Coordination

Registry Provides MechanismFor JIT, Customized Service Coordination

Other Registries:

JISC / IESR

OCLC OpenURL

Domain Name System (DNS)

UDDI

Ockham DDLSR Services

Discover

Locate

Interface

Goal: Service-to-Serviceaka

Machine-to-Machine

Current Status

• Version 0.7 released• A couple of major features left

– SRU/W Interface– Dropped peer handling

Some technical bits

• Using the JXTA framework for P2P / distributed functionality

• Java / Tomcat framework• Use OAI-PMH to mirror metadata records

in each node• Hierarchical network topology to handle

scalability of nodes

Reflections

• P2P– Useful in a distributed sense, but:

• Fairly heavyweight to implement• Everyone must run a node

– Current thinking: Distributed still has its advantages, but distributed <> p2p

Reflections

• Metadata– IESR is a comprehensive approach– Initial user feedback is that the amount of

metadata to be entered is a barrier– Much of the metadata description targets the

discovery need, and is not necessary for locate and interface (i.e. collection description)

Reflections

• Interface(s)– Still unclear which, if any, of the current

interfaces will be most utilized• Chicken and egg problem

– Human UI is currently important, although it is not strictly “core”.

• Overlaying application layer built on top of a standard submit interface?

Research Questions

• Distributed? To DNS-like or not DNS-like• Metadata model – minimalist or

comprehensive?• Which interfaces for Service-to-Service?

– Discover, Locate, Interface– Get, Put, Parse?

• What’s the killer registry app?– CoiNS / OpenURL, meta-search,

preservation, other?