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Subject: RE: TPA and ebXML Header question


Jim

I agree it will be a good idea to talk about this in Tokyo. My opinion is
that you can express behavior of the sender and receiver of a message
without having to define a Service Interface. For example you could say
something like ...

==================
If Delivery Semantics is "OnceAndOnlyOnce" then, unless a Data
Communications Protocol is being used that provides equivalent message
delivery reliability, the following behavior should be followed:
1. The Sender of a message should re-send the identical message if no
acknowledgement to the message is received
2. The Recipient of a message should check to see if a duplicate message has
been received before. If it has then the previous response to the message
should be sent, if it has not then the message should be passed to whatever
applicaiton needs to process it.

In the above, several parameters are required to control the behavior of the
sedner and receiver of the message. These parameters are:
1. The delay between the sending of an original message and its resending
2. The number of times a message is re-sent before a sender "gives up"
3. The action to take if a message cannot be sent
4. The length of time the recipient of a message retains message-ids and
replies to messages for duplicate checking purposes.

These parameters are determined either from:
a) the CPA that has been agreed between the sender and receiver
b) the Party Profile of the recipient, or
c) the default paramter value for ebXML, this is indicated by a CPA profile
of "ebXML:cpa1"
==================

The key point is you don't need to specify a Service Interface - let's
discuss in Tokyo

David


-----Original Message-----
From: Jim Hughes [mailto:jfh@fs.fujitsu.com]
Sent: Tuesday, October 24, 2000 2:21 PM
To: Transport Work Group
Cc: ebxml-tp@lists.ebxml.org
Subject: RE: TPA and ebXML Header question


I think the key point in your example is: where is the buffering (on the 
receiving side) and resending (on the sending side) being done? Nothing 
about buffering is prescribed for the Receiving_MSH in the current MS spec, 
and resending (for a certain number of tries, depending on some parameters) 
is done in the Sending_MSH. And, using some linearity prediction of 
reception rates (to set buffer size, etc.) certainly implies more than just 
awareness of a transport. We'll need to talk in Tokyo about this.

BTW, I think Marty is correct that some kind of Service Interface is needed 
to deal with it, especially with the current MS spec.

Jim

At 08:31 AM 10/18/2000 -0700, Burdett, David wrote:
>I think you can do sequencing without blocking on the RM ACK. In the
>following example a message is lost and resent ...
>
>Msg Seq No 1 --->               Passed to App
><--- Msg Ack Seq no 1
>Msg Seq No 2 --->               Passed to App
>Msg Seq No 3 --->       GETS LOST ON THE NETWORK
><--- Msg Ack Seq no 2
>Msg Seq No 4 --->               Buffered
><--- Msg Ack Seq no 4
>Msg Seq No 5 --->               Buffered
><--- Msg Ack Seq no 5
>Msg Seq No 3 ---> RESEND Passed to App
>                                 Pass Msg Seq no 4 to APP
>                                 Pass Msg Seq no 4 to APP
><--- Msg Ack Seq no 3
>
>... and if the transport sends messages out of sequence then you would get
>the following variation ...
>
>Msg Seq No 1 --->               Passed to App
><--- Msg Ack Seq no 1
>Msg Seq No 2 --->               Passed to App
>Msg Seq No 3 --->       IS DELAYED
><--- Msg Ack Seq no 2
>Msg Seq No 4 --->               Buffered
><--- Msg Ack Seq no 4
>Msg Seq No 5 --->               Buffered
><--- Msg Ack Seq no 5
>                                 Msg 3 arrives and is Passed to App
>                                 Pass Msg Seq no 4 to APP
>                                 Pass Msg Seq no 4 to APP
><--- Msg Ack Seq no 3
>
>The key point is that if the sender does not get the ack for message 3 then
>he will eventually re-send the original message as in the earlier example.
>
>Also if you know ...
>1. The arrival rate of messages and
>2. The timeout interval that triggers a resend if an ack is not received
>... then you can calculate the likely maximum size of your buffer. So if
the
>time out interval is, say 1 minute and you are sending two messages a
second
>and you assume that you have to do two re-tries before the message gets
>through then a buffer size of 3 x 120 or around 360 messages would be
>required, so make it a 1000 and it should suffice.
>
>If eventually the recipient fills up their buffer for that conversation
then
>it can send an error message in response to the lost message and stop
>buffering further messages.
>
>Thoughts?
>
>David
>-----Original Message-----
>From: Martin W Sachs/Watson/IBM [mailto:mwsachs@us.ibm.com]
>Sent: Wednesday, October 18, 2000 7:17 AM
>To: Burdett, David
>Cc: ebxml-tp@lists.ebxml.org; ebxml-transport@lists.ebxml.org
>Subject: RE: TPA and ebXML Header question
>
>
>
>Without blocking on the RM ACK, it is not sufficient to say that sequence
>numbers be used in conjunction with RM since a mis-ordering transport layer
>could still prevent bounding the number of messages to be stored.
>
>An alternative to blocking on the RM ACK, which I pointed out somewhere
>back in this thread, is to define the API to the messaging service such
>that a sending application  can block until the messaging service informs
>it that the message has been send.  This takes care of misordering by the
>messaging service with and without RM and misordering by the lower level
>transport.
>
>Historical item:  In the early '90s, the designers of the ANSI Fibre
>Channel standard discussed this issue endlessly.  The endpoint folks (I/O
>channels and device controllers) wanted to receive data frames in order but
>the frame-switch builders preferred to build misordering switches.
>Constructs were added to the end to end architecture to take care of the
>ordering problem for the acknowledged-frames (Class 2, for those into Fibre
>Channel terminology) but not for unacknowledged-frames (class 3).  The
>industry then moved toward a loop architecture which inherently keeps the
>frames ordered.  It still remains to be seen whether they really solved the
>ordering problem for frame switches.
>
>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
>***************************************************************************
*
>*********
>
>
>
>"Burdett, David" <david.burdett@commerceone.com> on 10/17/2000 11:13:07 PM
>
>To:   ebxml-tp@lists.ebxml.org, ebxml-transport@lists.ebxml.org
>cc:
>Subject:  RE: TPA and ebXML Header question
>
>
>
>I've been off-line for a while and just catching up ... this is, as several
>people have said, an interesting thread.
>
>My 2c worth ...
>
>Although it is useful to consider the use cases represented by the various
>business scenarios, I think we should focus on what we can document in the
>**protocol** with a perspective of whether or not is useful to higher
>layers.
>
>What I think would be a useful service is for the *receiving* MSH to be
>able
>to make sure that the application it is passing messages onto are delivered
>in the correct sequence. This could be used to makethe life of a business
>process easier, but it could also (again no rocks please) be used if you
>wanted to dis-assemble a large message and send each separately and then
>re-construct it at the receiving end.
>
>However this does imply buffering at the receiving end in order to ensure
>that the messages are passed on in the correct sequence. However, without
>some sort of "ack" that supports reliable messaging, the receiver has no
>way
>of informing the sender of messages that messages were lost in transit.
>
>So, how about us including a "sequence number" in the message header that
>has a semantic along the lines of ...
>
>"The optional Sequence Number identifies the sequence, within the
>ConversationId, in which messages received by the To Party SHOULD be
>processed. It is set to 1 and is then incremented by 1 for each message
>sent. If the To Party cannot process the messages in the specified sequence
>then it MUST return and Error Message."
>
>One question is how many messages should the receiver "buffer" before
>giving
>up. The receiver cannot keep on buffering messages indefinitely.
>
>One way around this problem is to recommend that sequencing of messages is
>only done in conjunction with reliable messaging. So we could also add to
>the spec ...
>
>"It is recommended that Sequence Number is used in conjunction with a
>Delivery Semantic of 'OnceAndOnlyOnce'. If the Delivery Semantic is not
>'OnceAndOnlyOnce' then the recipient of the message must either respond
>with
>an error message with a Severity of:
>* "Error" if it does not want to continue, or,
>* "Warning" if it does in which case, delivery of messages in the correct
>sequence is not guaranteed."
>
>Thoughts?
>
>David
>PS Trimmed the addresses.
>
>-----Original Message-----
>From: Martin W Sachs/Watson/IBM [mailto:mwsachs@us.ibm.com]
>Sent: Monday, October 16, 2000 7:56 AM
>To: Krishna Sankar
>Cc: Moberg, Dale; dick@8760.com; mark.hale@ajubasolutions.com;
>Christopher Ferris; 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
>
>
>
>(Please forgive the possible repetition.  It isn't clear to me that the
>following was transmitted the first time.)
>
>the IBM tpaML proposal has the notion of a conversation, which can be
>viewed as a session.  This notion includes multiple business processes at
>either end as long as each one can be represented by one or more actions
>(request/response pairs) within the same 2-party TPA.
>
>The tpaML conversation is above the level of the messaging service.  The
>messaging service has only to include the conversation ID in the message
>header (as it already does).  In the IBM proof of concept prototype (BPF),
>the middleware provides a set of application services such as conversation
>state tracking, sequencing rules, logging, security services, etc.  These
>services are the equivalent of the application services layer which people
>are starting to discuss in TRP and elsewhere
>
>Ordered delivery could be provided by the application services layer if the
>proper interface constructs are defined between the messaging service and
>the application layer.  At the sending end, ordering can be accomplished by
>the application services layer if it can block until the messaging service
>signals that it has sent the previous message (and assuming that a
>mis-ordering transport layer is not used). At the receiving end, I see
>little that the application services layer can do to maintain ordered
>delivery except to buffer up as many messages as required to correct
>misordering;  this requies that the sending application or application
>services layer apply a sequence number to each message.
>
>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
>***************************************************************************
*
>
>*********
>
>
>
>"Krishna Sankar" <ksankar@cisco.com> on 10/14/2000 03:34:21 PM
>
>To:   "Moberg, Dale" <Dale_Moberg@stercomm.com>, <dick@8760.com>, Martin W
>       Sachs/Watson/IBM@IBMUS, <mark.hale@ajubasolutions.com>
>cc:   "Christopher Ferris" <chris.ferris@east.sun.com>, 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-transport@lists.ebxml.org>
>Subject:  RE: TPA and ebXML Header question
>
>
>
>Hi all,
>
>      This thread is getting interesting.
>
>      One point I wish to make is the hypothesis that session could span
>multiple
>business processes. The business messages (using ack, accept et al) have
>the
>notion of virtual sessions. But business processes could be related ( and
>as
>Dale pointed out, this relationship need not even be linear) and would
>require some notion of a session to manage those relationships. And yes, I
>agree that this topic is not directly a trp issue.
>
>      cheers
>
>      Note : Even the POC retail example has the session notion; send order
>is
>related to the item alignment. In real life, for example RosettaNet, item
>alignment is the PIP2X and manage order is PIP3X - different BPs. Of
>course,
>we have the pseudo session by persistence (i.e. store the data and then
>other BPs can use it) in most cases, but there would be cases where we will
>need to have sessions to capture these relationships.
>
>-----Original Message-----
>From: Moberg, Dale [mailto:Dale_Moberg@stercomm.com]
>Sent: Saturday, October 14, 2000 11:53 AM
>To: 'dick@8760.com'; Krishna Sankar; Martin W Sachs/Watson/IBM;
>mark.hale@ajubasolutions.com
>Cc: Christopher Ferris; 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
>
>
>Dick,
>
>In the original OSI model there was both a presentation and
>a session layer between transport and the application layer. While
>MIME, security, packaging, routing elements-- as well as XML itself--
>are probably all best regarded as in the presentation layer,
>the use case Krishna presented is in the session layer.
>
>Applications could handle session, if they were newly created to know about
>PIPs, choreographics, and the more elaborate forking and joining BPs
>that Krishna clearly describes. These "sequencings" are clearly
>more elaborate than just a linear sequence and are more like
>trees where some of the branches join back up ( DAGs, lattices,
>and graphs for the mathematically inclined).
>
>Anyway, I believe that it is probably good to keep TRP out
>of the session layer and I fully support our TRP's
>scope constraint.
>
>Neverthless,  ebXML looks like it may need to
>consider developing specifications
>for session-related functionality for
>applications without session logic.
>Karsten Riemer at the recent TPA F2F indicated BP
>and the metamodel people are going to have BPs
>that have the more complex sequencing that Krishna
>discusses. Where exactly are ebXML specifications
>for the classic session layer under development?
>
>I think an element is falling through the cracks.
>
>
>Bye
>Dale Moberg
>
>
>
> > -----Original Message-----
> > From: Dick Brooks [mailto:dick@8760.com]
> > Sent: Saturday, October 14, 2000 10:08 AM
> > To: Krishna Sankar; Martin W Sachs/Watson/IBM;
> > mark.hale@ajubasolutions.com
> > Cc: Christopher Ferris; 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
> >
> >
> > Krishna,
> >
> > The scenario you describe is the management of the "application state
> > machine". The TR&P group has discussed the "scope" of state
> > management and
> > has determined that application state management belongs in
> > the application,
> > not in the Messaging Service. The Messaging Service must provide
> > "facilities" to assist the application layer in managing its
> > state machine
> > (e.g. context variables that are carried by the ebXML header
> > and passed thru
> > to applications), but not manage the application state
> > machine. The RM spec
> > defines much of what the TR&P group considers "transport state machine
> > management".
> >
> > Dick Brooks
> > Group 8760
> > 110 12th Street North
> > Birmingham, AL 35203
> > dick@8760.com
> > 205-250-8053
> > Fax: 205-250-8057
> > http://www.8760.com/
> >
> > InsideAgent - Empowering e-commerce solutions
> >
> > > -----Original Message-----
> > > From: Krishna Sankar [mailto:ksankar@cisco.com]
> > > Sent: Saturday, October 14, 2000 3:20 AM
> > > To: Martin W Sachs/Watson/IBM; mark.hale@ajubasolutions.com
> > > Cc: Christopher Ferris; 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
> > >
> > >
> > > List-Unsubscribe:
> > >  <mailto:ebxml-transport-request@lists.ebxml.org?body=unsubscribe>
> > > List-Archive: <http://lists.ebxml.org/archives/ebxml-transport>
> > > List-Help: <http://lists.ebxml.org/doc/email-manage.html>,
> > >  <mailto:ebxml-transport-request@lists.ebxml.org?body=help>
> > >
> > > Hi all,
> > >
> > >  We can think of many business scenarios which needs sequencing.
> > >
> > >  One such example is the capturing state transitions of a
> > > process e.g..
> > > order status in the case of a heavy equipment manufacturer and
> > > it's agents:
> > >
> > >  Assume orders go thru "recvd", "scheduled", "in mfg",
> > > "ready to ship" and
> > > "shipped". Assume the manufacturer captures these states
> > and exchange
> > > messages across an ebXML network to it's agents. Now if these
> > > states trigger
> > > work flow processes at the agents' end, sequencing is important.
> > > For example
> > > a "ready to ship" might invoke (at the agent's side) a request for
> > > preparation for goods receiving (example prepare customs
> > papers, book
> > > shipping containers) and a "shipped" status could trigger
> > activate a firm
> > > commitment on the containers (booked by the earlier state)
> > >
> > >  The systems at the agents end has no way of controlling
> > > sequencing ! It has
> > > to be guaranteed by the sending side and/or the messaging
> > system. If the
> > > agent receives out of sequence messages, for example a
> > "shipped" message
> > > before a "ready to ship" message, would cause problems.
> > >
> > >  Another example is that of exchanging prices from a seller
> > > to a buyer. A
> > > seller might change prices many times and if the messages are not
> > > sequenced,
> > > the buyer would end up getting the prices in a random order
> > ! And the
> > > problem here is that the buyer has no way of controlling or
> > knowing the
> > > sequences !
> > >
> > >  In the above examples, without RM, we will not be able
> > to guarantee
> > > anything and that is not acceptable. With RM, we also face
> > the need to
> > > guarantee the sequencing ! It would be nice if the messaging
> > > guarantees the
> > > sequencing so that the business processes need not worry about
> > > this issue. A
> > > counter point is that, in a distributed system, which
> > consists of many
> > > components (e.g. servers) and multiple modes of interaction (e.g..
> > > SMTP,HTTP...), we cannot guarantee who might generate
> > messages and so
> > > sequencing is still a business process issue.
> > >
> > >  I know that B2B products (e.g.. from WebMethods and
> > > Netfish) face this
> > > issue. Any idea how they are handling this ?
> > >
> > >  cheers
> > >
> > > -----Original Message-----
> > > From: Martin W Sachs/Watson/IBM [mailto:mwsachs@us.ibm.com]
> > > Sent: Friday, October 13, 2000 3:35 PM
> > > To: mark.hale@ajubasolutions.com
> > > Cc: Christopher Ferris; 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
> > >
> > >
> > >
> > > OK, we have possible scenarios for which the business
> > process is not in a
> > > position to guarantee ordering except by applying a
> > sequence number and
> > > buffering as many messages as necessary to correct misordering (I
> > > mis-spoke
> > > before when I said that it cannot maintain order without
> > business level
> > > responses).
> > >
> > > Now, I had been initially concerned about ordering because
> > RM's recovery
> > > procedure will get messages out of order if blocking is not
> > in force.  I
> > > have been assuming, without thinking about it, that if RM
> > is not in use,
> > > the messaging service will send messages in order on a given logical
> > > channel.  Is it valid to assume that without RM, the messaging
> > > service will
> > > in fact maintain order at its level?  If not, should it?  If
> > > blocking is an
> > > option with RM, then an application which needs ordering without
> > > application-level responses could request RM with blocking
> > to maintain
> > > order.
> > >
> > > Of course if the underlying transport misorders (SMTP?),
> > then all bets are
> > > off.
> > >
> > > 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
> > > ******************************************************************
> > > **********
> > > *********
> > >
> > >
> > >
> > > "Mark Hale" <mark.hale@ajubasolutions.com> on 10/13/2000 04:52:47 PM
> > >
> > > Please respond to <mark.hale@ajubasolutions.com>
> > >
> > > To:   Martin W Sachs/Watson/IBM@IBMUS, "Christopher Ferris"
> > >       <chris.ferris@east.sun.com>
> > > 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-transport@lists.ebxml.org>
> > > Subject:  RE: TPA and ebXML Header question
> > >
> > >
> > >
> > > > 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
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> > >
> >


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