Re: SequenceNumber [was:minutes 21-Dec-2000 tr&p con-call]

[SHIMAMURA Masayoshi <shima.masa@jp.fujitsu.com>]

Mr. David Burdett, 

On Wed, 03 Jan 2001 12:05:59 -0800
"Burdett, David" <david.burdett@commerceone.com> wrote:
...
> This is not my recollection. In fact if you look at the DTD in version 0.8
> of the spec you will see that SequenceNumber need not be present in a
> Routing Header (see line 1268) which is defined as follows ...
> 
> <!ELEMENT RoutingHeader (SenderURI , ReceiverURI , ErrorURI , Timestamp ,
> SequenceNumber? )>
> 
> Making SequenceNumber mandatory is something that we did not agree to do.

The SequenceNumber is needed when DeliverySemantics is "OnceAndOnlyOnce".
So the DTD was defined as above, I think.

> Also the current version of the spec uses sequence number so that the
> recipient can detect duplicates. However, as Chris Ferris says is in his
> email, this doesn't always work. Some additional situations which cause
> problems are:
...
> However I can see how preserving the sequence could be useful and important
> to some applications. So in the current 0.91 version of the spec, the
> definition of SequenceNumber is defined as being unique within Conversation
> Id so that if you need to preserve message order then you can.

I agree to generation of SequenceNumber for each ConversationId. Thank
you for your suggestion. I hope you also add detailed description of
SequenceNumber and new attribute "messageOrderSemantics" of
ReliableMessagingInfo to the MS spec. I show my modification idea in
attached file.


Regards, 

--
SHIMAMURA Masayoshi <shima.masa@jp.fujitsu.com>
TEL:+81-45-476-4590(ext.7128-4241)  FAX:+81-45-476-4726(ext.7128-6783)
Planning Dep., Strategic Planning Div., Software Group, FUJITSU LIMITED

Modification_to_MS3.doc