RE: WSDL Import/Include Locations

Yaron wrote:

> One of the most common ways to deal with unreliability is to 
> make information available at distinct locations. The advantage 
> of making data available at distinct locations is that not only 
> does it provide reliability in the face of endpoint failures but 
> it also provides reliability in the face of network failures.


Actually something that has always bothered me about the /list/ of 
locations in WSDL and Schema: if a list is essential for resilience
then why don't other languages such as HTML have a list of URIs in 
<a href='...' etc ? 

My most common use for the location /list/ has been to put a relative 
URI followed by an absolute URI so that a the same schema may be used
stand alone on my laptop before being deployed on Web server elsewhere.

Also I have a competing use-case against multiple locations: 

Before signing-off a Web service we test and validate the service
using a captured WSDL saved in our configuration management system. 
This captured WSDL must be stand-alone since the WSDL published by 
the service may later change. It's also not acceptable to store a
serialisation of the infoset since this is different to the actual
published documents, invalidating any regression testing.

So we need to not only store the root document but any other
documents referenced and in a way that emulates how a consumer 
of the actual service would have worked. 

Here the redundancy lists only exasperates this difficulty since 
it is possible for two test runs to be presented with two different 
sets of documents.  

So a single URI in the location and having some environmental change 
to subvert the processor (a 'PATH' variable) would be preferable 
here rather than having to edit the WSDL document and invalidate
our regression tests.

Just another reason why concentrating on what is a valid WSDL
document rather than the behaviour of a WSDL processors is very 
useful.

Paul

-- 
Paul Sumner Downey
Web Services Integration
BT Exact

Received on Tuesday, 9 March 2004 05:34:12 UTC