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Re: Version attribute for WSDL

From: Prasad Yendluri <pyendluri@webmethods.com>
Date: Tue, 17 Feb 2004 16:52:48 -0800
Message-ID: <4032B760.9010704@webmethods.com>
To: www-ws-desc@w3.org
Messing with the namespace URI (and effectively changing namespace) for 
versioning seems undesirable to me.
I like to keep version a separate attribute distinct from the namespace 
and actually I prefer that it be a +ve numerical.
A higher value representing a younger (subsequent) version than the 
lower valued one. Also IMO we
must clearly define the semantics of this attribute lest we end up 
creating another area of confusion.
The following semantics look good to me.

The version attribute indicates a "minor" revision of the definition or
interface. Specifically, a "minor" revision indicates that a client using
a WSDL with a version attribute less-than the current value is expected
to continue to function.

In essence I am for Tom's (2nd) proposal below except the approach 
suggested in example 2. When an incompatible change is made,
it should be left up to the WSDL writer to decide how to change the 
namespace URI rather the spec dictating it.

I don't quite understand the issue with defaulting the version to "1" if 
not set explicitly however...

Regards, Prasad

-------- Original Message --------
Subject: 	RE: Version attribute for WSDL
Resent-Date: 	Fri, 13 Feb 2004 18:49:15 -0500 (EST)
Resent-From: 	www-ws-desc@w3.org
Date: 	Fri, 13 Feb 2004 15:48:53 -0800
From: 	Vambenepe, William N <vbp@hp.com>
To: 	David Orchard <dorchard@bea.com>, <paul.downey@bt.com>, 
<tomj@macromedia.com>, <www-ws-desc@w3.org>


My mistake, I thought you were suggesting doing URI tricks inside a
"version" attribute that would be of type URI. Yes, I fully agree with
doing this in the URI that represents the namespace. This is what I
meant in a previous email: "maybe what we need instead is an optional
convention on how to build interface QNames that convey versioning
information. Whether that convention belongs in the WSDL spec is another
question...""

So +1 from me that this is the right approach. I am not sure this group
needs to specify that, but it's fine by me if many people want it in our
spec.

William

> -----Original Message-----
> From: www-ws-desc-request@w3.org 
> [mailto:www-ws-desc-request@w3.org] On Behalf Of Vambenepe, William N
> Sent: Friday, February 13, 2004 12:41 PM
> To: David Orchard; paul.downey@bt.com; tomj@macromedia.com; 
> www-ws-desc@w3.org
> Subject: RE: Version attribute for WSDL
> 
> 
> > I wonder if we could play some magic trick and say that the 
> > minor version is a relative URI from the namespace name, and 
> > then the "match" could be of the strings.  A nice use of URIs 
> > for comparison imo.
> 
> Why not play that trick on the URI part of the QName of the interface?
> 
> William
> 
> > -----Original Message-----
> > From: www-ws-desc-request@w3.org 
> > [mailto:www-ws-desc-request@w3.org] On Behalf Of David Orchard
> > Sent: Friday, February 13, 2004 12:13 PM
> > To: paul.downey@bt.com; tomj@macromedia.com; www-ws-desc@w3.org
> > Subject: RE: Version attribute for WSDL
> > 
> > 
> > Ah Paul,
> > 
> > I had earlier thought about using URIs for the "minor" 
> > version # and the problem of multiple nested versions and you 
> > are probably right about the problem of increasing minor versions.  
> > 
> > Tell me though, is 3.3 compatible with 3.2.1.1?  I would 
> > assume they would have to be.
> > 
> > I wonder if we could play some magic trick and say that the 
> > minor version is a relative URI from the namespace name, and 
> > then the "match" could be of the strings.  A nice use of URIs 
> > for comparison imo.
> > 
> > Dave
> > 
> > > -----Original Message-----
> > > From: www-ws-desc-request@w3.org 
> > [mailto:www-ws-desc-request@w3.org]On
> > > Behalf Of paul.downey@bt.com
> > > Sent: Friday, February 13, 2004 10:02 AM
> > > To: dorchard@bea.com; tomj@macromedia.com; www-ws-desc@w3.org
> > > Subject: RE: Version attribute for WSDL
> > > 
> > > 
> > > 
> > > I like this too, especially the defaulting on extension.
> > > 
> > > My small concern is using the integer to indicate the relationship
> > > between versions precludes branches, unless we allowed a  SCCS/RCS/CVS 
> > > style numbering system, e.g:
> > > 
> > > 1 -> 2 -> 3 -> 4 -> 5 
> > >           |
> > >           +-> 3.1 -> 3.2 -> 3.3 
> > >                      |
> > >                      +-> 3.2.1
> > >                          |
> > >                          +-> 3.2.1.1 
> > > 
> > > i imagined the proper W3C way would be to use a URI for the 
> > > version and 
> > > relate them using syllogisms ?
> > > 
> > > Paul
> > > 
> > > 
> > > -----Original Message-----
> > > From: www-ws-desc-request@w3.org 
> > [mailto:www-ws-desc-request@w3.org]On Behalf Of David Orchard
> > > Sent: 13 February 2004 17:47
> > > To: 'Tom Jordahl'; www-ws-desc@w3.org
> > > Subject: RE: Version attribute for WSDL
> > > 
> > > 
> > > I like this as a strawman.  And the idea of not inheriting the version
> > > attribute makes a certain sense too, as it requires the "extender" to make a
> > > conscious decision.  Though defaulting to "1" does have the problem that the
> > > extender might not be compatible.  If there were some way in the "extension"
> > > of knowing that the extensions could be ignored, then "1" makes sense.
> > > 
> > > cheers,
> > > Dave
> > > 
> > > > -----Original Message-----
> > > > From: www-ws-desc-request@w3.org 
> > > [mailto:www-ws-desc-request@w3.org]On Behalf Of Tom Jordahl
> > > > Sent: Friday, February 13, 2004 7:06 AM
> > > > To: 'www-ws-desc@w3.org'
> > > > Subject: RE: Version attribute for WSDL
> > > >
> > > >
> > > > I guess I understand the desire to have "real" versioning support in WSDL
> > > > 2.0.  I do too. But my proposal came out of the F2F, where we had a long,
> > > > and I believe fruitless, discussion about all of this.
> > > >
> > > > I do not believe we can have a section in our specification about versioning
> > > > and say "if you want versioning, change the namespace". With a small
> > > > addition to the syntax, we can give users some help in managing change in
> > > > their web services.
> > > >
> > > > I am willing to apply semantics to the version attribute if this group
> > > > thinks that they can move forward in a productive way.  How about these
> > > > changes as a straw man for discussion:
> > > >
> > > >  - The version attribute is part of the infoset (a.k.a. the component model)
> > > >
> > > >  - The version attribute has type xsd:positiveInteger
> > > >
> > > >  - The version attribute has a default value of 1.
> > > >
> > > >  - The version attribute indicates a "minor" revision of the definition or
> > > >    interface. Specifically, a "minor" revision indicates that a client using
> > > >    a WSDL with a version attribute less-than the current value is expected
> > > >    to continue to function.
> > > >
> > > >  - When an interface extends another interface, the version attribute of the
> > > >    interface is NOT inherited - it must be explicitly set on the interface,
> > > >    and if is not, the interface has the default version attribute (1).
> > > >
> > > > Example 1: Version 1 of my interface has two operations. I release a new
> > > > WSDL that adds a third operation, and change the version attribute to 2.
> > > > Clients who are using the previous version of the WSDL continue to function.
> > > >
> > > > Example 2: My WSDL has a purchase order type defined and a target namespace
> > > > of "http://example.org/myservice".  I change my purchase order to include
> > > > several new elements and rename some of the old ones.  Since this change
> > > > will break compatibility, I change the target namespace to
> > > > "http://example.org/myservice/v2".  My service can now easily tell the
> > > > difference between clients that are using the original WSDL
> > > > and the new one.
> > > >
> > > >
> > > > --
> > > > Tom Jordahl
> > > > Macromedia Server Development
> > > >
Received on Tuesday, 17 February 2004 19:52:50 UTC

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