WSO2 today hosts the WS-Metadata Exchange Interop Workshop here in Auburn, California.  Representatives from Microsoft, IBM, WSO2, Sun, Oracle, and Adobe are currently present, and already showing some initial progress at running the interop scenarios.

WS-Metadata Exchange is a fairly simple spec, allowing one to approach another service and query it about it’s capabilities (WSDL, XML Schema, WS-Policy).  Having a common way to do some initial handshake allows services to bootstrap communication with each other.  I think the most likely scenario for this is doing some alignment of security policies so that subsequent communications can be done in a secure fashion.

Update: As of Thursday, we had overall excellent interop results with most of the matrix filled in green.  Still a few reds in the matrix between a few vendors that will hopefully get filled in next week.  Overall, I think the meeting went very well and I think everyone enjoyed coming to the "WSO2 Auburn campus."  Hopefully we can make this a regular occurrence!

I’d hoped to announce WSDL 2.0 was a Proposed Recommendation by now, but we hit another small delay - the W3C team thought it prudent to do another short Last Call to make sure people were aware of the namespace change.

WSDL 2.0 adopts the namespace convention http://www.w3.org/ns/wsdl instead of the dated URL http://www.w3.org/2006/01/wsdl.  The idea is to make the namespace shorter and more memorable, especially since it’s used as the base not only for the WSDL 2.0 family of namespaces, but also for other identifiers defined in the language, such as style and message exchange pattern identifiers.

However, changing the namespace when going to Proposed Recommendation seems to have raised some eyebrows.  I’m not precisely sure why.  It does destabilize implementations underway during the Candidate Recommendation - just as you achieve a level of successful interop the fundamental identifier of the language changes.  But in this case we believe we know very well who the implementers are and we verified that a namespace change was manageable.

It seems semantically pure to change the namespace when significant changes to the spec have been made.  In the case of WSDL, the most significant change was the removal of features and properties.  The resulting language is different enough to warrant a namespace change.  Features and properties were marked as "at risk" which is supposed to (in part) reserve the ability of the group to proceed from Candidate Recommendation to Proposed Recommendation without another Last Call period.  But apparently this doesn’t extend to the accompanying namespace change?  Puzzling.

I suppose the best advice I can give on namespace changes is to replace the long (1 year+) Candidate Recommendation phase with a shorter series of CR or even LC publications whenever a major change occurs.  That way the final CR to PR transition will be wholly editorial.

That said, arguably a more important reason than a namespace change, is to allow the WG to prove more definitively the utility of the WSDL 2.0 HTTP binding by demonstrating its ability to describe some popular existing HTTP based services.  That proof is unfortunately missing at present and it is a wise task for the WG to engage in.

In any case, get your comments in by this Sunday, that’s when the Last Call period ends!