Re: [ebxml-msg] MessageOrder Issue, Conversation Termination

[Pete Wenzel <pete@seebeyond.com>]

I don't think this has appeared on the issues list yet; Doug, please
note.

Thus spoke Pete Wenzel (pete@seebeyond.com) on Tue, Mar 04, 2003 at 02:29:20PM -0800:
> I'd like to raise an issue regarding a deficiency in the MessageOrder 
> Module.  As of 2.0c, there seems to be no way of indicating that a 
> conversation is complete.  The receiving party must remember the last 
> SequenceNumber received for each ConversationId indefinitely, because it 
> must continue to expect more messages to arrive in that sequence.
> 
> I propose two solutions:
> 
> 1.  For 2.0 errata, recommend that an implementation-dependent 
> conversation timeout be chosen (or configurable).  It may be measured 
> either from the 0th message's timestamp, or from the time of the last 
> received message.  In the first case, the timeout must be greater than 
> the expected conversation duration (if the process is specified by BPSS, 
> timeToPerform may be used).  In the second case, the timeout must be 
> greater than any expected message's TimeToLive, plus the expected 
> interval between messages in the sequence.
> 
> 2.  For a permanent solution in the next rev of the spec, add a value of 
> "Last" to the SequenceNumber/@status enumeration, used to indicate the 
> final message of the conversation.

Additionally, permit a "Last" signal message with no payload, to
indicate that the previously received message was the last one in the
conversation (in case the sending MSH wasn't informed of this fact
before the last one was sent).

> --Pete
> Pete Wenzel <pete@seebeyond.com>
> SeeBeyond
> Standards & Product Strategy
> +1-626-471-6311 (US-Pacific)