Minutes: XDI TC Telecon Thursday 1:00-2:30PM PT 2012-01-12

[Drummond Reed <drummond.reed@xdi.org>]

Following are the minutes of the unofficial telecon of the XDI TC at:

Date:  Thursday, 12 January 2012 USA

Time:  1:00PM - 2:30PM Pacific Time (21:00-22:30 UTC)

ATTENDING

Mike Schwartz 

Giovanni Bartolomeo

Markus Sabadello

Drummond Reed 

Joseph Boyle

REGRETS

Bill Barnhill 

THE IDEARPAD LINK FOR TODAY IS:

     http://piratepad.net/3GsPcga5is

1) IDTRUST BUDGET

Great news - the budget request for $5K for interop testing of an XDI client operating against two XDI servers was approved! Dee Schur has sent a contract to Markus to review and will have a call with him to go over it.

We discussed the configuration that we would use for it. Markus and Mike will coordinate the details.

# MARKUS AND MIKE will work out a plan for executing and keep the TC appraised of progress.

2) OPEN SOURCE PROJECT UPDATES

Mike said that the OpenXDI Project released version .2, and is now working on the front end needed by MIT. Work now will go into OxAuth.

The next improvements on OxServer will be optimizations on search, plus work on the OGM (Object Graph Mapping) tool.

Markus said he is beginning work on changes to the Project Danube code base, and will have more to update next week.

3) LINKED DATA UPDATE

Giovanni said that Linked Data is becoming the defacto standard for sharing data, and governments are starting to look at it as the standard for publishing data. He said the Italian Government (after the US, UK and French Governments), for example, is exploring it now. 

Giovanni believes that XDI should be 100% compatible with Linked Data. The key question that he would like to have researchers explore is defining what XDI can add to Linked Data. The first point of addition is the ability to address single nodes inside the graph. The second point is control of data sharing using link contracts.

Giovanni explained that Linked Data implementers approach the problem of identification from a different perspective. For example, two different RDF graphs from two different authorities may use different URIs to represent the same entity. What is emerging now is the pattern of using hubs to share URIs that represent a specific entity (including a concept, such as an ontology definition, or a place, or a product, etc.)

If this trend continues, of referencing/sharing a single "very popular URI", then Giovanni believes we can map to that URI from an XRI using either (or both):

• A cross-reference

• A short-form XRI, which would provide a single short-form "canonical" identifier for the entity.

Giovanni feels that if we take this approach, we can help solve the problem of disambiguating attributes assigned to the same entity (identified by a popular URI/XRI) in two different contexts from two different RDF authoritities. The solution is to make each set of attributes relative to each of the two authorities using the contextual capability of XDI.

Giovanni is currently working using statistical techniques to analyze part of the Linked Data cloud (which is up to 32 billion Linked Data triples) to identify what appear to be the same entity in different contexts. Once these are identified, then the XRI can be assigned that would become the canonical identifier for that resource.

Using this approach -- this XDI dictionary "hub" that establishes the equivalence of different URIs -- software that uses the hub can do the mapping across RDF graphs, and then the next step is that the data publishers can start using longer URIs that incorporate XRIs into their URIs - making them longer but also embedding the XRI identifier in such a way that the equivalence can be recognized by processing agents.

Mike pointed out that by creating URI "hubs", the Linked Data community is already starting to add a data abstraction layer and create canonical identifiers. Giovanni agreed and said that because this is happening, it sets up the business case for them to start to use what is specified in the XRI 3.0 spec, which is to use a concrete http: or https: URI to identify the provenance of the RDF graph bound to an XRI to identify the entity. That is a very elegant solution that provides a bridge between the RDF Linked Data world and the XDI world.

# GIOVANNI will work out a roadmap for how he sees this unfolding, and then post an update.

4) AUTO-INCREMENT

Mike sent this message to the list:

   http://lists.oasis-open.org/archives/xdi/201201/msg00006.html

He explained that the use case is very common where you need the server to add the next available i-number for identifying an node.

Drummond and Markus immediately recognized this pattern as something they had to deal with in a Higgins-related project several years ago. The solution that we developed was to send the server a $add operation with a variable in the XRI for the XDI object. The server would see the variable and then replace it and return the value to the client.

Here is what we agreed on the call, to use variables:

<$sender>/$add/(=schwartz/()/($1))

<$sender>/$add/(=schwartz/()/($2))

<$sender>/$add/(=schwartz($1)/()/+friends)

<$sender>/$add/(=schwartz($2)/()/+friends)

The server would assign the next available unordered index and returns it in the response to the client.

5) PROPOSALS FOR OPTIMIZING $GET - XDI QUERIES

Continuation of last week's discussion. See:

  http://ox.gluu.org/doku.php?id=xdi:get

  

Drummond and Markus brought up that a basic query syntax was developed a few years ago and actually implemented by Markus. Originally developed by Giovanni and with some patterns suggested by Bill, it was very simple yet very elegant.

# MARKUS agreed to look up the source documents and help port that syntax forward to the XDI TC wiki page(s) that Mike is creating for a query syntax.

Mike suggests we also discuss via email to be ready for a live discussion on next week's call.

6) XDI MESSAGE ORIGINATION SOLUTION

Drummond said that he had added the basic solution as the revised first line (the "from" line) of the XDI message template:

  http://wiki.oasis-open.org/xdi/XdiMessagePatterns

We ran out of time to discuss it on this call, but Drummond will add more documentation, and we will discuss it next week.

6) NEXT CALL

Although Drummond will be in Europe, he still hopes to be able to attend the call, and in any case it will be next week at the regular time.