Duplicate of Delivered Fault revisited

[Tom Rutt <tom@coastin.com>]

I have come up with a scenario, that makes me want to reconsider sending 
an ack for a dupcate of delived message.

Suppose we have a wsdl , non idempotent, request response operation type 
which the user wants to protect with ws-reliability.

Lest look at the response reply patern .

So if the first time the operation is invoked, the receiver will deliver 
it, and the operation response will carry the rm ack.

Now if the sender gets nervous and resends just before it receives an 
ack, it will be detected as duplicate, by the receiving rmp.  Now
the receiving rmp must not deliver this second operation invocation to 
the receiving app, so what does it put in the soap body for
this response.  We are calling it a rm ack, so we will not trigger a 
fault condition.

What would happen if the body was empty, with no indication of faulut in 
the ws response header.

Perhaps we should return a "duplicateOf Delivered" fault code to convey 
the situation in an unambiguous manner.

-- 
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Tom Rutt		email: tom@coastin.com; trutt@fsw.fujitsu.com
Tel: +1 732 801 5744          Fax: +1 732 774 5133