Re: [wsrm] Singleton group with SequenceNumber?

[Sunil Kunisetty <sunil.kunisetty@oracle.com>]

Tom Rutt wrote:

> Tony Graham wrote:
>
> >>From off-list mail:
> >
> >Sunil Kunisetty <sunil.kunisetty@oracle.com> wrote at Fri, 20 Feb 2004 17:49:54 -0800:
> >
> >
> >>Tony Graham wrote:
> >>
> >>
> >...
> >
> >
> >>>What about the singleton case that also has a sequence number?
> >>>
> >>>
> >> In our colloquial references, a singleton is a message without SeqNum.
> >> If it has a SeqNum, then it is considered has a Group. A group of
> >> 1 is still valid.... In such case, the following example will apply
> >>
> >>
> >
> >If you mean considering a Group with only one message (that uses
> >SequenceNum) as a Group for the purposes of reporting an
> >Acknowledgment or Fault for that Group, then I see what you mean.
> >

 YES.

>
> >However, Section 2.3 says, beginning at line 512, that a singleton
> >group can be a message with a SequenceNumber:
> >
> >   (1) In case there is only one message in the group (singleton): the
> >       group ID, which is a globally unique group identifier, may be
> >       used alone as Message Identifier. No sequence number is
> >       required, although allowed.
> >
> >I asked on Monday [1] what a singleton group with a sequence number
> >would look like. (Well, I really just said that the spec should provide
> >an example.)
> >
> >A group of 1 is not valid since the 'status' attribute can't indicate
> >both the start and end of a group, and the 'status' value has to be
> >'Start' for the first message in a group (line 989):
> >
> >   The sender node MUST send a very first message, to guarantee the
> >   message order, with "Start" for this attribute.
> >

 Here is the glitch.  The 'end' message is NOT A MUST for a group to
 be complete. As such the group can be terminated (and hence completed)
 by other criteria such as group expiry time, max idle duration etc...

 So 'end' message is just a convenience. We cannot enforce that every
 group MUST only be completed by an 'end' message.

>
> >...
> >
> >
> >> Currently there is no way to distinguish a Group with only one message
> >> (that uses SequenceNum)  as a Singleton unless Request Header is
> >> also changed to reflect something similar.
> >>
> >>
> >
> >Then Section 2.3 should be changed or the 'status' attribute should
> >allow a 'Single' value (or similar).  At this point I think that it
> >would be simpler to change Section 2.3.

 I think this is not necessary as I explained above. It may help a
 a group of 1 message case, but then it will be very error prone
 for other cases.

>
> >
> I agree it would be easier to have a singleton group never use the
> sequence no in its request.
>

 We really cannot enforce this and atmost can suggest in bold letters
 that it is efficient for singleton messages to be without no seq.o.

>
> If this was the case, how would your proposed schema for the
> messageReplies look like?
>
> Tom Rutt
>
> >
> >Regards,
> >
> >
> >Tony Graham
> >------------------------------------------------------------------------
> >Web Products, Technologies and Standards           Phone: +353 1 8199708
> >Sun Microsystems                                              x(70)19708
> >East Point Business Park, Dublin 3, Ireland
> >
> >
> >[1] http://www.oasis-open.org/archives/wsrm/200402/msg00127.html
> >
> >To unsubscribe from this mailing list (and be removed from the roster of the OASIS TC), go to http://www.oasis-open.org/apps/org/workgroup/wsrm/members/leave_workgroup.php.
> >
> >
> >
>
> --
> ----------------------------------------------------
> Tom Rutt                email: tom@coastin.com; trutt@fsw.fujitsu.com
> Tel: +1 732 801 5744          Fax: +1 732 774 5133
>
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