RE: [ws-rx] Re: Action Item #0125

["Durand, Jacques R." <JDurand@us.fujitsu.com>]

Inline <JD>

-----Original Message-----
From: Matthew Lovett [mailto:MLOVETT@uk.ibm.com]
Sent: Wednesday, January 17, 2007 1:02 AM
To: ws-rx@lists.oasis-open.org
Subject: [ws-rx] Re: Action Item #0125

Hi all,

Here's my attempt at wordsmithing the DA text. I put in an introductory paragraph, which I think captures Chris's intent.

Ashok: I haven't taken your concern about the fault case into account, as I think the same text applies for application messages that generate faults. Perhaps I've misunderstood your point. Could you try to change the introduction to cover your concern?

--

Each delivery assurance is described in terms external to the RM
Destination / Application Destination interface. Some implementations may
have advanced capabilities, such as the ability to rollback and retry
message processing, but the observable effect must be as described.

AtLeastOnce ? each message within the Sequence that is received and
acknowledged by the RM Destination is processed to conclusion at least
once.

<JD> can we be more precise about "process to conclusion" ? what kind of guarantee does that give to a user of the RM layer (RMS+RMD)? Where does "delivery"  come into play,  like in "delivery assurance"?

Any message in the Sequence that is received and acknowledged by the
RM Destination might be processed to conclusion more than once. Duplicate
message filtering is not required to achieve this delivery assurance, and
SHOULD NOT be applied to the Web service.

<JD> I believe we do not need to recommend anything for or against duplicate elimination here - isn't logically AtLeastOnce implied by ExactlyOnce? It would be confusing if not.

AtMostOnce ? each message within the Sequence that is received and
acknowledged by the RM Destination is processed to conclusion at most
once. Any message within the Sequence that is received and acknowledged by
the RMD might not be processed to conclusion.

<JD> this last sentence above probably needs some rewording  as it contradicts the first one - I assume we mean " that has already been processed to conclusion". Also the above definition seems to apply duplicate elimination  only to messages that have already been acknowledged. It appears to allow duplicate deliveries in case the first message is not yet acknowledged (could happen if the acknowledgment is not done each time a message is received, but is grouped for several messages.)

Duplicate message filtering
is required to achieve this delivery assurance, and MUST be applied to the
Web service.

ExactlyOnce ? each message within the Sequence that is received and
acknowledged by the RM Destination is processed to conclusion exactly
once. Duplicate message filtering is required to achieve this delivery
assurance, and MUST be applied to the Web service. The Web service SHOULD
make every effort to ensure that each message is processed to conclusion.

--

Thanks

Matt