Re: [ebxml-msg] Interaction between AckRequested,DuplicateElimination,and SyncReply elements

[Doug Bunting <db134722@iPlanet.com>]

Hmmm,

That wasn't my reading of 2.0 rev C.  If others agree it's a possible reading of
the text, it should be fixed.  I agree with Arvola that duplicate elimination
and returning a copy of the first response should be triggered by the
DuplicateElimination element.  AckRequested should simply determine whether or
not that first response includes an Acknowledgment element.

Were others confused?  What change would improve the wording?

thanx,
    doug

Arvola Chan wrote:

> Doug:
>
> In earlier versions of the spec when we had only the concept of Reliable
> Messaging and not separate control of AckRequested and DuplicateElimination,
> it was clear that whenever a receiver receives a reliably delivered message
> that is not a duplicate, it is obligated to at least make a persistent copy
> of the message ID as well as a persitent copy of the first response message.
> When a received reliably delivered message is determined to be a duplicate,
> the receiver is supposed to return the saved first response message.
>
> Now that AckRequested and DuplicateElimination can be controlled separately,
> it is not clear whether the behavior to save the first response message and
> to return the saved first response message in reply to a duplicate message
> is triggered by the AckRequested element or by the DuplicateElimination
> element.
>
> I would have preferred that the above behavior be triggered by the
> DuplicateElimination element. However, Version 2.0 rev C indicates that the
> above behavior should only be exhibited by the receiver MSH if the
> AckRequested element is present.
>
> Regards,
> -Arvola
>
> -----Original Message-----
> From: Doug Bunting [mailto:db134722@iPlanet.com]
> Sent: Wednesday, March 27, 2002 11:58 AM
> To: Arvola Chan
> Cc: ebXML Msg
> Subject: Re: [ebxml-msg] Interaction between AckRequested,
> DuplicateElimination,and SyncReply elements
>
> [Please note: Yes, this is still me.  I had to change email addresses due to
> Yahoo! changes.]
>
> Arvola,
>
> This is a very good point covered slightly by issue 127 and might touch on
> issues 165-166.  If we must interpret "do nothing" or "ignore", it should be
> explained in the text or an errata.
>
> In this particular case, the sender isn't waiting for an MSH signal in
> general.
> It should be waiting for the (stored) business response.  (The duplicated
> elimination flag indicates that response must have been stored.)  The text
> is
> incomplete around a more specific sub case of what you've described: when
> CPA
> syncReplyMode="MSH Signals" (or whatever the next level above "none" is
> called)
> and not a mode involving application information.  With that clarification,
> the
> original message would also have a problem because no information was
> available
> to reply on the synchronous channel.
>
> The most efficient response when no information is really required would be
> a
> 200 OK.  Closing the connection would only tell the originator to start
> retry
> cycles.  However, sending a "real" body (probably, just an ebXML
> MessageHeader
> element) in the synchronous reply could be useful for duplicate elimination
> cases, allowing the receiver to store something as their response.
>
> thanx,
>     doug
>
> Arvola Chan wrote:
>
> > I like to address the following question, mostly to folks who have already
> > implemented ebMS 2.0.
> >
> > If the sender MSH includes a DuplicateElimination element and a SyncReply
> > element, but no AckRequested element in an ebXML message, and the receiver
> > MSH determines that the received message is a duplicate, should it simply
> do
> > nothing, as prescribed on line 1681 in the Version 2.0 rev C spec?
> >
> > The problem of doing nothing is that the sender MSH is waiting for a
> > synchronous reply. The connection will not get closed until some timeout
> > parameter kicks in either on the sending or receiving side. This doesn't
> > seem an efficient way of using network resources. Can "do nothing" be
> > interpreted as closing the connection, or returning a 200 OK status code
> and
> > closing the connection?
> >
> > -Arvola
> >
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