+1
Christopher Ferris
STSM, Software Group Standards Strategy
email:
blog: http://www.ibm.com/developerworks/blogs/dw_blog.jspa?blog=440
phone: +1 508 377 9295
Doug Davis/Raleigh/IBM@IBMUS wrote on 03/23/2006 08:22:45
AM:
>
> Bob - this gets into the entire DA issue which is out of scope. All
> the RMD can/should say is whether or not it got the messages - and
> that list of messages should never decrease. If there are gaps
in
> the sequence then the RMS will know which messages will be delivered
> (or not) based on the DA in use. How it knows the DA is out
of scope :-)
> thanks,
> -Doug
>
>
>
> "Bob Freund-Hitachi" <>
> 03/23/2006 06:35 AM
>
> To
>
> Doug Davis/Raleigh/IBM@IBMUS, "[WS-RX]" <>
>
> cc
>
> Subject
>
> RE: [ws-rx] New Issue; SequenceAcknowledgement:Final assumption of
> deliverability
>
>
>
>
> Doug
> If “taking responsibility” for a message implies that at least an
> attempt to deliver the message will be made, then I guess that the
> previous ack of a message with a sequence number larger than a gap
> is untruthful if in-order delivery is enforced.
> The proposal allows the rmd to correct the previous misstatement,
> which it had no way of knowing was untruthful at the time it was
> made. The RMS had the expectation at the previous acknowledgement
> that further messages may be coming which was shattered when the
> sequence was closed without that expectation being met.
> The RMS has no way of knowing that ordered delivery was in effect,
> so it cannot second guess the RMD.
> Alternatively, we could say that all messages that have been
> acknowledged will be delivered, on at least a best-efforts basis,
> independent of in-order delivery and the existence of gaps in the
sequence.
> Or, we could define durable persistence and a way for sequences to
> be resumed after closure (I think just too complicated)
> Thanks
> -bob
>
>
>
>
> From: Doug Davis [mailto:]
> Sent: Wednesday, March 22, 2006 10:54 PM
> To: Bob Freund-Hitachi
> Cc: [WS-RX]
> Subject: Re: [ws-rx] New Issue; SequenceAcknowledgement:Final
> assumption of deliverability
>
>
> Bob,
> I'm confused - doesn't the sending of an Ack for a certain message
> number already imply that the RMD is taking responsibility for it?
> If only SeqAck+Final means that, then does that mean that a SeqAck
> (non-final) means something less? like a lie?
> -Doug
>
> "Bob Freund-Hitachi" <>
> 03/22/2006 02:07 PM
>
> To
>
> "[WS-RX]" <>
>
> cc
>
>
>
> Subject
>
> [ws-rx] New Issue; SequenceAcknowledgement:Final assumption of deliverability
>
>
>
>
>
>
>
>
>
>
>
>
> Description
> Modify definition of SequenceAcknowledgement:Final to reflect
> accurate ending delivery capability status.
> Justification
> The protocol defines the SequenceAcknowledgement:Final element which
> contains the final summary of message acknowledgements at the
> closure of a sequence. It is assumed that the RMD has taken
> responsibility for all messages that have been acknowledged.
> Depending upon the operation of the RMD and its interface with the
> application, Messages that have been previously acknowledged as
> received by the RMD, may never be deliverable. One such case
of
> note that comes to mind is the situation of a message sequence that
> is being delivered in-order to an application which is closed at the
> time when one or more gaps that may exist in the sequence. If
this
> situation occurs, the RMS will have incorrect information concerning
> exactly which messages have been or will be deliverable at the
> conclusion of a sequence.
> Note that there is nothing in the spec that states what the RMS is
> to do with the information contained in SequenceAcknowledgement:
> Final. This proposal does not add any such statement, but it
does
> permit the information to be potentially interpretable.
> Target: core
> Proposal:
> Reference Core Spec CD03
> insert after line 613:
> SequenceAcknowledgemnt:Final shall identify only those messages that
> have been delivered or which the RMD has taken responsibility for
> delivery without regard to the previous acknowledgement status of
any message.
> State Table impact: None
>
