Re: Question on relation between roles and wsdl interfaces

Dear Mine,

All interactions in WS-CDL define an operation name over a channel  
and include a relationship name and the from and to roles for that  
interaction. Optionally one may specify a set of exchanges (up to 3  
normally, one for the request, one for the response and one for a  
fault response). The operation name may be used to tie back to a WSDL  
operation for the to role. If one projects out all of the operations  
for a specific to role in a WS-CDL description one would get an  
ordered set of of WSDL operations. The WS-CDL defines the multi-party  
ordering and the end point projection provides the specific role's  
ordering.

In the definition of a role type in WS-CDL an optional interface can  
be included. This may be a reference to a specific WSDL and this ties  
the role to a specific service contract.

Thus you always know which operation is invoked during an interaction  
because the operation name and the to-role are defined.

So I would say you are almost correct but that you missed the point  
about the role being an abstract that has specific ordering  
constraints on the service operations. Generally a role has a single  
behavior but that does not have to be the case.

If you want to find out further details carry on mailing this list  
but you might want to cross post or look at the pi4soa implementation.

Cheers

Steve T

On 1 Dec 2006, at 22:49, Mine Altunay wrote:

>
> Dear list
> My understanding of current ws-cdl standard was that each role can  
> have multiple behaviors and each behavior corresponds to an  
> operation listed within a service's wsdl. As a result, I view a  
> role as an abtraction that is a collection of service operations.  
> Each time a different behavior is assumed by a role, the  
> corresponding web service operation would be invoked.
>
> My confusion arises when I try to define interactions between  
> different roles. An interaction consists of a relationship type and  
> defines fromRoleTypes and toRoleTypes. However it does not specify  
> which behaviors can be assumed during the specific interaction  
> between two roles.
>
> My problem exacerbates when I try to tie in a choreography document  
> with a run time execution environment. Since I do not know which  
> operation is invoked during an interaction, determining run-time   
> operation sequences between actual web service implementations is  
> almost impossible.
>
> Can anyone enlighten me on this? am I incorrect to tie in behaviors  
> with actual web services operations
> Thank you
> ....Mine
>
>
>
> Mine Altunay
> NC State Univ, Computer Eng Dept
>
>
>
>
>

Received on Saturday, 2 December 2006 09:16:09 UTC