Re: Simple Choreography composition suggestion

Martin Chapman wrote:

>
><martin> how do i know what is inside or outside the choreogrphy? all a we
>can observe is
>that a (starting) message is sent from one party to another. if i substiute
>the actual instances of the
>orginating party the receiving party cant tell the difference. Also there
>may be many entry points, on different parties so its not the same as a
>single web service described by a single wsdl.
>  
>
Not how do you know, but what you define.

If you define a (closed) choreogaphy involving A and B and it starts 
when A sends a message to B, then you expect whoever takes the role of A 
to, amongst other things, to send that first message.

If you define a (open) choreogaphy involving A and B but someone else 
sends the first message, then you need to have some port available for 
receiving that message, in essense either marking one of the services as 
an entry point, or defining yet another service.

You might not be able to do a blind test to tell which is which, but 
since these are two different use cases you would create two different 
definitions to make the semantic difference obvious.

arkin

Received on Thursday, 17 July 2003 18:54:26 UTC