> -----Original Message----- > From: Dan Diephouse [mailto:[EMAIL PROTECTED] > Sent: 11 January 2007 17:44 > To: [email protected] > Subject: Re: Identification of Partial Responses > > A quick question about the two way case - if its already > decoupled, why can't the server sent out a > <SequenceAcknowledgement> at some point during the two way > operation.
The wsa:replyTo and wsrm:acksTo are specified *independently*, and may well be different. The twoway case in which we absolutely *need* partial responses, is where the wsa:replyTo is non-anonymous but the wsrm:acksTo is anonymous. So even though the MEP is decoupled for application-level message, ACKs cannot be sent as you describe in this scenario. > For instance we have this scenario > > - A sends message to B > - B takes an hour before it sends its response back to A > - During this time B sends a one way SequenceAcknowledgement > to A so as to avoid resends Only if *both* the wsa:replyTo and wsrm:acksTo are non-anonymous, a SequenceAcknowledgement could be sent as you describe. In fact we already do this. But its still useful (if not absolutely necessary) to send partial responses even in this case. Remember that RM ACKs acknowledge the *entire* set of messages received thus far for a particular sequence, not just the individual current message. So we may well have pending ACKs backed up from the previous incoming messages, when the current message is received. Rather than going to the trouble of immediately opening a separate server->client connection to send these backed up ACKs, its much more sensible to piggy-back them on the back-channel of the incoming connection on which we received the current request. However, this is just for convenience, so lets not argue the point. The main issue that makes your suggestion unworkable is pointed out above, i.e. the decoupled replyTo but anonymous acksTo case. At this stage we really need to bring this thread to a conclusion. Challenging the groupthink is a very useful exercise, but its beginning to burn a lot of time, and I feel that we're inching inexorably to a consensus that partial responses (with some minor mods) are actually required. So can we agree that the partial response mechanism has survived the (sustained ;) challenge? Cheers, Eoghan
