RE: [ebxml-msg] Reliable Messaging question

[Dick Brooks <dick@systrends.com>]

David,

 

I'm not sure I understand this statement from the spec: "...there is an unrecoverable error in the message and no further messages will be generated as part of the conversation."   

 

If a ConversationID is synonymous with a "Session" there will likely be multiple message exchanges, including some with ErrorList, throughout the course of the session. IMO, the spec should not dictate the behavior of a Conversation, this is application specific. 

 

It may be the intent of this statement is to indicate the "responder" will send no further "responses" after issuing an ErrorList. That is understandable. However, a client MUST be able to send additional request messages over the same ConversationId, after receiving an ErrorList response, and the server should be able to respond to these additional requests.

 

Dick Brooks
Systrends, Inc
7855 South River Parkway, Suite 111
Tempe, Arizona 85284
Web: www.systrends.com <http://www.systrends.com>
Phone:480.756.6777,Mobile:205-790-1542,eFax:240-352-0714
 

-----Original Message-----
From: David Fischer [mailto:david@drummondgroup.com]
Sent: Thursday, February 14, 2002 11:04 AM
To: mwang@tibco.com; ebxml-msg@lists.oasis-open.org
Subject: RE: [ebxml-msg] Reliable Messaging question

The spec says, in section 4.2.3.2.4, that if there is an error severity of Error, "...there is an unrecoverable error in the message and no further messages will be generated as part of the conversation."  How can we then continue to send retries after an ErrorList with error severity of Error? 

 

Maybe the problem we need to clarify is in the Error section rather than in the RM section?  OTOH, maybe the statement in 4.2.3.2.4 is enough.

 

Regards,

 

David.

-----Original Message-----
From: Michael Wang [mailto:mwang@tibco.com]
Sent: Thursday, February 14, 2002 2:57 AM
To: ebxml-msg@lists.oasis-open.org
Subject: Re: [ebxml-msg] Reliable Messaging question

If the position is to let the retry kick in then are we saying the sender MSH
should "ignore" the ErrorList message and just let the retry to complete?
Then report back to application of the N retries it did and all the Errors it
got back?

David's comment makes sense.  I can't think of a reson why I would respond
in the same message with an Acknowledgment element AND an ErrorList
element .  I would only ack a message after all MSH level related validation
has passed.

May be too late for 2.0 but I would say this introduces unnecessary complexity.
Should probabaly be looked into post 2.0.

-mw
 

Doug Bunting wrote:

David,

Almost every error may be transient.  Further, our documentation gives no "out" for the sending MSH other than exceeding the Retries parameter or receiving an appropriate Acknowledgment.  Adding the ErrorList element to that list of outs would be very different from 1.0 and would involve multiple changes to our document.  That's in spite of the a receiving MSH already being able to send ErrorList and Acknowledgment together.

125 was an editorial issue because the other parts of our specification were clear what could stop retries.  The section referenced in issue 125 muddied things.  Let's not turn this into a new technical issue.

thanx,
    doug

David Fischer wrote:

Why would an MSH continue sending retries after receiving an ErrorList for that MessageId?  Section 6.5.7 indicates that when a message cannot be delivered then a DFN must be returned.  You are right though, it doesn't actually say not to send any more retries. I'm a little confused...  If an Acknowledgment is present with an ErrorList, does that mean the MSH does or doesn't send a DFN to the application?  I suppose if the message got far enough so that the receiving MSH could actually generate an Acknowledgment then that would constitute delivery for the purposes of RM? I think this would be OK -- send an ErrorList and an Acknowledgment together.I'm still not clear why the sending MSH would continue to send retries if it got an ErrorList (containing the appropriate RefToMessageId) from the receiving MSH but without an Acknowledgment?Regards,David FischerDrummond Group.

-----Original Message-----
From: Doug Bunting [mailto:dougb62@yahoo.com]
Sent: Wednesday, February 13, 2002 7:23 PM
To: ebxml-msg@lists.oasis-open.org
Subject: Re: [ebxml-msg] Reliable Messaging question

Arvola,

I believe this is captured in issue 125.  In David's response [1], he indicated an ErrorList could end retries but that interpretation is not borne out by our current documentation and seems incorrect.  I would suggest we stick with the current retry semantics and end retries only upon receipt of an Acknowledgment or exhaustion of allowable retries.  If a MSH receiving a message in error chooses to respond with an Acknowledgment bundled together with an ErrorList, fine.

I also agree this option (combining Acknowledgment with ErrorList) isn't well described.  Improving that description was the intent of issue 125.

thanx,
    doug

[1] http://lists.oasis-open.org/archives/ebxml-msg/200202/msg00006.html (specifically, the XML file attached and unhelpfully inlined by the OASIS site)

Arvola Chan wrote:

 Section 7.5.2 in Draft version 2.0 describes Receiving Message Behavior under the ebXML Reliable Messaging Protocol. It does not mention anything about error handling. Suppose the received message is erroneous (e.g., some elements in the message are inconsistent with the CPA), the receiver is obligated to return an Error message. It is not clear to me if an Acknowledgment MUST also be included in the Error message. Does the Error message serve as an implicit Acknowledgement? Will the sender keep retrying until it gets back an Acknowledgment (i.e., as long as the number of allowable retries have not been exhausted)? Thanks,-Arvola

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