Uniform Resource Names:Deploying A New Namespace

Michael Mealling19 August 1999

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Overview of URNs

Meant to be persistent identifiers. Binding to resource is permanent.

Simple identification is useful (XML namespace identification)

A resolution system is available if needed. Allows for variety in the syntax of the namespace. Examples:

– URN:ISBN:0-07-882396-X– URN:PDI://oma.eop.gov.us/1999/8/5/14.text.2

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Deployment Issues

Problem identification Experimentation Development Adoption Scaling Management

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Problem Identification

We know the general class of problems. Now we need to look at specific ones and apply the proposed solution.

– Bibliographic identifies (ISBN, ISSN, DOI)– Schema identification (XML Namespaces)– Document Management (PDI, IETF)– Distributed object systems (Globe)

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Experimentation

Once the problems are identified internal use and experimentation begins.

– Hidden deployment issues appear. (I.e., the ‘u’ flag issue)

– Reusable code begins to appear.– Corporate resource begin to be committed.– We are nearing the end of this phase. Several

experiments are ready for “prime time”

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Development

Developers begin work on solutions to the problems. Issues to be aware of:

– Interoperability– Adherence to the standard. If a large enough

segment of the user base does something incorrectly, that incorrect behavior becomes a de facto standard.

– Open source software provides a common reference implementation.

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Adoption

Moving URNs into the main stream– Must be a compelling reason for either the user or the service

provider?– For the user it must be either ‘sexy’ or extremely useful (or at least

a functional requirement of something that is).– For the service provider it must be essential for some product that

is sellable.– Chicken and egg problem (No one uses it because the software

doesn’t support it. The software doesn’t support it because no one uses it.)

– Killer app?

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Scaling

Scaling of assignment– The IANA is currently the NID authority. Will this

scale? Scaling of resolution

– Is a DNS based RDS capable of scaling well enough? Scaling of actual resolution servers

– Is THTTP to simple?– Are other protocols or protocol profiles needed?

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Management

To early to tell. If we knew what they would be we could fix them now.

Some possibilities:– Namespace specific knowledge allows for special

casing certain URNs which affects interoperability– What happens if we a namespace becomes so popular

that it “takes over” the URN space? (I.e. the .com phenomenon happens to URNs)

Michael Mealling19 August 1999TWIST MeetingUniversity of California, Irvine

Current Status

URN Working Group waiting on final documents which are in Last Call.

Namespace registration procedures are being setup now. At least 4 namespaces are in the process of registering.

Software is being released for browsers Real Soon Now ™.