RE: concatenating web services

Don Box wrote on 02/10/2003 12:11:35 PM:

<snip/>
> 
> For what it's worth, the team I work on (we build the SOAP stack for our
> company's operating system) has done a fair amount of navel
> contemplation on this one. Our primary conclusion was that because SOAP
> has no notion of message identity, intermediaries have a great deal of
> freedom. That stated, here are some guidelines to think about:
> 
> 1) Intermediaries SHOULD NOT contradict the intention of the original
> sender and the ultimate receiver. When these two conflict, the ultimate
> receiver's intention wins.

Intention for what? This guideline seems to me to have a very RPC-style 
bias. In a
pub/sub environment, neither the intent of the message publisher nor that 
of 
the message's subscriber(s) is necessarily known to any other than itself. 
In fact,
the publisher may not be aware of the existance of the subscriber(s). How 
is an 
intermediary to "know", or even guess at the intent of the ultimate 
recipient?
Can the intent of the original sender be "known" to be anything more than 
that
it intends the message to be delivered to the ultimate recipient?

> 
> 2) Intermediaries SHOULD NOT change the "action" of the message. If you
> are going this far, consider becoming an ultimate receiver.

What is the "action" of the message?

<snip/>

Cheers,

Christopher Ferris
Architect, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
phone: +1 508 234 3624