RE: TPA and ebXML Header question

[Mark Hale <mark.hale@ajubasolutions.com>]

> The problem arises if the application involves a series of one-way
> messages, required to stay in order but with no business-level response.
> There is no way for the business process level to enforce ordering because
> the sender of a message doesn't know when it is safe to send the next one.
> The RM component of the messaging sequence can enforce ordering
> by blocking
> on each message in a logical channel until it receives the RM
> Acknowledgment.  That's why I suggested that blocking in the RM
> function be
> controlled by a tag in the CPA and CPP. The blocking would be effective
> only for the particular TPA.
>
> Is this a realistic case?  I don't know.  Can anyone tell us?

I can see the following scenarios where one way messages with blocking may
be desired:

- Exchanges where one partner may be a high-throughput hub coalescing
ordered data from subsidiaries
- Omni-directional peer battlefield simulation (HLA work from DoD)

	Thanks,

	Mark



> -----Original Message-----
> From: Martin W Sachs/Watson/IBM [mailto:mwsachs@us.ibm.com]
> Sent: Friday, October 13, 2000 1:27 PM
> To: Christopher Ferris
> Cc: Scott Hinkelman/Austin/IBM; Bob Haugen; David RR Webber; Zvi
> Bruckner; ebxml-tp@lists.ebxml.org; ebxml-transport@lists.ebxml.org
> Subject: Re: TPA and ebXML Header question
>
>
>
> Chris,
>
> I don't believe that pushing ordered messaging up to the business process
> level is the answer.  Consider:
>
> If all the messages at the business process level are request-response,
> with only one message at a time, as in tpaML with its sequencing rules,
> then it doesn't matter what the messaging service does because the
> combination of request-response and one-at-a-time sequencing will preserve
> order within a conversation.
>
> The problem arises if the application involves a series of one-way
> messages, required to stay in order but with no business-level response.
> There is no way for the business process level to enforce ordering because
> the sender of a message doesn't know when it is safe to send the next one.
> The RM component of the messaging sequence can enforce ordering
> by blocking
> on each message in a logical channel until it receives the RM
> Acknowledgment.  That's why I suggested that blocking in the RM
> function be
> controlled by a tag in the CPA and CPP. The blocking would be effective
> only for the particular TPA.
>
> Is this a realistic case?  I don't know.  Can anyone tell us?
>
> Regards,
> Marty
>
> ******************************************************************
> *******************
>
> Martin W. Sachs
> IBM T. J. Watson Research Center
> P. O. B. 704
> Yorktown Hts, NY 10598
> 914-784-7287;  IBM tie line 863-7287
> Notes address:  Martin W Sachs/Watson/IBM
> Internet address:  mwsachs @ us.ibm.com
> ******************************************************************
> *******************
>
>
>
> Christopher Ferris <chris.ferris@east.sun.com> on 10/04/2000 10:51:10 AM
>
> To:   Martin W Sachs/Watson/IBM@IBMUS
> cc:   Scott Hinkelman/Austin/IBM@IBMUS, Bob Haugen
>       <linkage@interaccess.com>, David RR Webber <Gnosis_@compuserve.com>,
>       Zvi Bruckner <zvi.b@sapiens.com>, "ebxml-tp@lists.ebxml.org"
>       <ebxml-tp@lists.ebxml.org>, "ebxml-transport@lists.ebxml.org"
>       <ebxml-transport@lists.ebxml.org>
> Subject:  Re: TPA and ebXML Header question
>
>
>
> A minor tweak below, otherwise, I concur.
>
> Chris
>
> Martin W Sachs/Watson/IBM wrote:
> >
> > Summing up what I think I have seen on MS ACKS (composite of
> opinion, not
> > necessarily consensus):
> >
> > MS ACKs are needed (this is essential to reliable messaging)
> >
> > The messaging service should not require blocking of a logical channel
> > until an MS ACK is received.
> >
> > Blocking may in any case be enforced by business-level responses.
> >
> > Partner Profile and Partner Agreement should specify whether blocking is
>                                          ^^^^^^^
> s/b sequencing IMHO. That is to say that at the business process level
> (not conversation) the sequence of messages might be enforced/required.
>
> > required.
> >    Note:  in my opinion, this tag would refer to the messaging service
> >    ACKs, not the business process.  Blocking at the business process
> level
> >    would be specified in the business process model and manifest itself
> in
> >    the PA in the response definitions and sequencing rules or whatever
> >    equivalent we come up with.
> >
> > New point:  For many applications, the latency effects of
> blocking at the
> > MS level would be substantially reduced if what we are calling a logical
> > channel is really a conversation.  A good implementation would provide
> for
> > many concurrent conversations even within a single PA.  Thus when the MS
> > blocks until receiving an ACK it would only affect the conversation of
> > which the message and ACK are a part.
> >
> > Regards,
> > Marty
> >
> >
> ******************************************************************
> *******************
>
> >
> > Martin W. Sachs
> > IBM T. J. Watson Research Center
> > P. O. B. 704
> > Yorktown Hts, NY 10598
> > 914-784-7287;  IBM tie line 863-7287
> > Notes address:  Martin W Sachs/Watson/IBM
> > Internet address:  mwsachs @ us.ibm.com
> >
> ******************************************************************
> *******************
>
> >
> > Scott Hinkelman/Austin/IBM@IBMUS on 10/04/2000 10:17:01 AM
> >
> > To:   Bob Haugen <linkage@interaccess.com>
> > cc:   Martin W Sachs/Watson/IBM@IBMUS, David RR Webber
> >       <Gnosis_@compuserve.com>, Zvi Bruckner <zvi.b@sapiens.com>,
> >       "ebxml-tp@lists.ebxml.org" <ebxml-tp@lists.ebxml.org>,
> >       "ebxml-transport@lists.ebxml.org"
> <ebxml-transport@lists.ebxml.org>
> > Subject:  RE: TPA and ebXML Header question
> >
> > It is fine if a specific business process utilizes business level acks.
> > A robust ms also needs ms level acks.
> > There is a need for both.
> >
> > Scott Hinkelman, Senior Software Engineer
> > XML Industry Enablement
> > IBM e-business Standards Strategy
> > 512-823-8097 (TL 793-8097) (Cell: 512-940-0519)
> > srh@us.ibm.com, Fax: 512-838-1074
> >
> > Bob Haugen <linkage@interaccess.com> on 10/03/2000 07:14:05 PM
> >
> > To:   Martin W Sachs/Watson/IBM@IBMUS, David RR Webber
> >       <Gnosis_@compuserve.com>
> > cc:   Zvi Bruckner <zvi.b@sapiens.com>, "ebxml-tp@lists.ebxml.org"
> >       <ebxml-tp@lists.ebxml.org>, "ebxml-transport@lists.ebxml.org"
> >       <ebxml-transport@lists.ebxml.org>
> > Subject:  RE: TPA and ebXML Header question
> >
> > Marty and David,
> >
> > All of the business aspects of document processing,
> > including what kinds of acks are expected, are defined
> > by the Commercial Transaction patterns that are part
> > of the BP Collaboration Metamodel now (finally)
> > posted on the BP work page at:
> > http://www.ebxml.org/project_teams/business_process/wip/index.html
> >
> > (They are actually pretty much the same as RosettaNet,
> > so the POC vendors should know how to handle them.)
> >
> > -Bob Haugen
> >
> > -----Original Message-----
> > From:     Martin W Sachs/Watson/IBM [SMTP:mwsachs@us.ibm.com]
> > Sent:     Tuesday, October 03, 2000 6:13 PM
> > To:  David RR Webber
> > Cc:  Zvi Bruckner; ebxml-tp@lists.ebxml.org;
> > ebxml-transport@lists.ebxml.org
> > Subject:  Re: TPA and ebXML Header question
> >
> > DW,
> >
> > Isn't the confirm you are talking about part of the business
> process?  It
> > seems to me that you want the business process to say "I got it" rather
> > than having the messaging service say "I was able to parse it OK and
> passed
> > it on to the business process but I it isn't my job to know if the
> business
> > process actually got it or fumbled the ball."
> >
> > Regards,
> > Marty
> >
> >
> ******************************************************************
> *******************
>
> >
> > Martin W. Sachs
> > IBM T. J. Watson Research Center
> > P. O. B. 704
> > Yorktown Hts, NY 10598
> > 914-784-7287;  IBM tie line 863-7287
> > Notes address:  Martin W Sachs/Watson/IBM
> > Internet address:  mwsachs @ us.ibm.com
> >
> ******************************************************************
> *******************
>
> >
> > David RR Webber <Gnosis_@compuserve.com>@compuserve.com> on 10/03/2000
> > 06:46:02 PM
> >
> > To:   Martin W Sachs/Watson/IBM@IBMUS
> > cc:   Zvi Bruckner <zvi.b@sapiens.com>, ebxml-tp@lists.ebxml.org,
> >       ebxml-transport@lists.ebxml.org
> > Subject:  Re: TPA and ebXML Header question
> >
> > Message text written by Martin W Sachs/Watson/IBM
> > >I believe there is a strong case for an optimistic
> > protocol: send only "checked not ok" and let the business-level response
> > imply that the message was delivered to the application with no error.
> >
> > Regards,
> > Marty<
> >
> > >>>>>>>>>>>>>
> >
> > Marty - this will depend on the business workflow use case.  Some
> > will require an explicit confirm - before proceeding to the next step.
> >
> > We should support both models - but default to
> > 'delivery accepted without confirm'.
> >
> > DW.
>
> --
>     _/_/_/_/ _/    _/ _/    _/ Christopher Ferris - Enterprise Architect
>    _/       _/    _/ _/_/  _/  Phone: 781-442-3063 or x23063
>   _/_/_/_/ _/    _/ _/ _/ _/   Email: chris.ferris@East.Sun.COM
>        _/ _/    _/ _/  _/_/    Sun Microsystems,  Mailstop: UBUR03-313
> _/_/_/_/  _/_/_/  _/    _/     1 Network Drive Burlington, MA 01803-0903
>
>
>