RE: [ws-rx] PR issue 09

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

Paul:

Let me reword one of the concerns I see in the eAC comment:

- because DAs are not specified - although often expected, as our
charter recognizes - some WS-RM implementers may be led to establish a
proprietary way to do it that requires use of extensibility points in
the RM protocol, for signaling these DAs or parameters of these DAs.
This way could become a de-facto standard for a significant part of the
market (just an hypothesis, but quite possible).

- if this happens, there would be interop issues with other RM endpoints
that may not support these extensions, when you look at the bigger
picture (RM protocol + DAs) even though you may still have
interoperability at RM protocol level alone, since an RMD/RMS may ignore
any extension. In case these other implementations want to align with
the practice, besides the trouble in upgrading already deployed
products, there might be unexpected IP issues.

So the worst interoperability scenario for those who need to communicate
DA data, would be if sometime later this comes to affect implementations
of the lower protocol layer - RMS/RMD.

Short of specifying DAs somewhere (and the way to communicate them) I
see no good solution for preventing this scenario except getting rid of
extensibility points... 

Jacques



-----Original Message-----
From: Paul Fremantle [mailto:paul@wso2.com] 
Sent: Thursday, October 26, 2006 4:23 PM
To: Durand, Jacques R.; ws-rx@lists.oasis-open.org
Subject: Re: [ws-rx] PR issue 09

Jacques

I understand what you are saying. I'm trying to understand how we would 
prove something so obvious :-)

Our protocol ensures that the messages are correctly transmitted to the 
RMD together with a message number, which increases by one.

So even if we did define this in our specification, the text would sound

pretty lame:

i.e.
"To achieve the "ordered delivery" delivery assurance, the RMD must 
deliver the messages in the order of the MessageNumbers."
"To achieve the AtMostOnce delivery assurance, the RMD must only deliver

one message with a given MessageNumber"
"To achieve the AtLeastOnce delivery assurance, the RMD must ensure that

it delivers each transmitted message with a given MessageNumber."

As regards your second point, I have some sympathy for that.

Paul


Durand, Jacques R. wrote:
>
> I think the issue is not so much "how can I implement my DAs on top of

> this protocol" . Many folks in eAC are quite experimented with RM and 
> have known sequence numbers way before WS-RX started.
>
> But without going as far as bringing back the DAs, at a minimum it 
> would be helpful to demonstrate the following, either in the spec 
> (appendix) or in a companion doc:
>
> - whatever DAs (among most popular ones) are defined on top of this 
> protocol, and assuming both sides are aware of which DA is being used 
> (communicated out of band), then the protocol as defined is sufficient

> to *enable* the DAs and does not need additional interoperability 
> tightening or extensions when actual DAs are implemented. Were it 
> otherwise, it would mean that proprietary extensions to the protocol 
> are needed that would introduce both interop and IP issues.
>
> Now that probably isn't enough to make everyone happy. Standard DAs to

> choose from, along with their parameters, are still expected from some

> users and are considered as part of the interop equation. But wherever

> these are defined - either wsrmp or elsewhere - it is important to 
> show first that this has no bearing on the wsrm protocol layer and its

> implementations, i.e. this layer can be considered stable.
>
> -Jacques
>

-- 
Paul Fremantle
VP/Technology and Partnerships, WSO2 
OASIS WS-RX TC Co-chair

http://bloglines.com/blog/paulfremantle
paul@wso2.com
(646) 290 8050

"Oxygenating the Web Service Platform", www.wso2.com