[cddlm] Schema Policy

[Steve Loughran]

As we discussed on the project phone conference yesterday, we are having 
fun with schema versions. To summarise

1. component model and API use the IBM-namespaced WSRF specs (the 
original set), and WS-Addressing of 2003

2. if you pull down the "latest" versions of WSRF & WSN you find out 
they are inconsisent with each other

3. WSDM has been approved by OASIS, based on draft 0.1 of WSRF and WSN.

3. WSN draft 0.1 uses WSA 2003 for addressing

4. WSDM uses WSA 2004 for addressing, except when using WSN 
notifications, at which point WSA 2003 has to be used. Apart from 
different namespaces, the two versions are apparently identical.

5. WSA addressing is still evolving at the W3C. A version may be 
standardised this year, a version which is likely to be somewhat 
incompatible with either WSA2003 and 2004.

6. Any attempt to use the latest stuff in the CDDLM component model and 
deploy API is a painful and futile way to waste days of your life.

Stuart, Dejan and myself had a phone discussion with some of the WSDM 
team yesterday, then Stuart and I discussed what our policy should be. 
Here it is

1. We will use draft-0.1 of the OASIS versions of WS-RF, WS-N for our 
WSRF schemas.

2. We will use wsa: to refer to WSA 2003/04 everywhere . Our addresses 
will be compatible with the draft of WS-N

3. We will declare the wsa2004: alias to the WSA 2004/08 namespace. This 
will only be used in returning MOWS identity references.

4. We indent to update this stuff when the underlying specifications are 
standardises. Specifically, once WSA becomes a W3C release, and the 
WSRF, WSN, WSDM specs are updated to reflect that change, then we will 
move too. We are not going to chase latest versions of other peoples 
specs when some of the core underpinnings are still unstable, as it 
vastly complicates the interoperability story. There will be no attempt 
to revisit the versions until that point, so people can work with the 
CDDLM specification knowing that we are not going to update it every month.

Note that Apache Hermes/Muse is compatible with our versioning policy. 
That is, they currently use the same versions we do. I will keep an eye 
on them to keep them in line.

Life would have been easier if WSDM had used the same version of the 
addressing specification as the rest. Although both Stuart's and my 
companies voted for WSDM as it stands, we do understand the viewpoint of 
the few organisations that voted against it on the grounds of unstable 
foundations. But It has happened;  all we can do is manage the 
implications for us and for people who work with the CDDLM framework.

-Steve