Re: Documentation need for value of context by value (was RE: [ws-caf] Mt Everest and WS-CF)

["Mark Little" <mark.little@arjuna.com>]

I'm happy with that.

Mark.

----
Mark Little,
Chief Architect, Transactions,
Arjuna Technologies Ltd.

www.arjuna.com

----- Original Message -----
From: "Furniss, Peter" <Peter.Furniss@choreology.com>
To: "Greg Pavlik" <greg.pavlik@oracle.com>
Cc: "Mark Little" <mark.little@arjuna.com>; "Green, Alastair J."
<Alastair.Green@choreology.com>; "ws-caf" <ws-caf@lists.oasis-open.org>
Sent: Sunday, May 30, 2004 1:03 AM
Subject: Documentation need for value of context by value (was RE: [ws-caf]
Mt Everest and WS-CF)


> Greg,
>
> Should have replied earlier.
>
> Depends on whether the spec has much material on the use and purposes of
> ws-context, or just a limited summary of what it is. I think this is a
> question (in one of its formulations) that needs to be covered in all
> but the shortest explanations.  The spec is currently pretty terse, so
> it may be appropriate to have this in supporting material.
>
> Peter
>
>
>
> > -----Original Message-----
> > From: Greg Pavlik [mailto:greg.pavlik@oracle.com]
> > Sent: 27 May 2004 14:17
> > To: Furniss, Peter
> > Cc: Mark Little; Green, Alastair J.; ws-caf
> > Subject: Re: [ws-caf] Mt Everest and WS-CF
> >
> >
> > Peter, would it simply be satisfactory to address these questions
> > directly in the FAQ or primer?
> >
> > Furniss, Peter wrote:
> >
> > >I'll restate the documentation question I raised on this:
> > >
> > >Does the specification state what are the advantages of using
> > >ws-context by-value over and above using a SOAP header with the same
> > >application information.
> > >
> > >Does it state what considerations would lead a designer to choose to
> > >define a use of ws-context by-value instead of defining a
> > soap header.
> > >
> > >I don't believe the question (which is quite distinct from
> > the question
> > >of value OR reference) has ever had a documented answer. It has been
> > >discussed (at least in Paris, I'm not sure if it was
> > discussed since),
> > >but where is the answer ?
> > >
> > >I raised it as a documentation question precisely because I
> > don't want
> > >force revisitation if the answer is in fact already well
> > known to most
> > >of the TC.
> > >
> > >Peter
> > >
> > >-----Original Message-----
> > >From: Mark Little [mailto:mark.little@arjuna.com]
> > >Sent: 27 May 2004 11:42
> > >To: Green, Alastair J.; ws-caf
> > >Subject: Re: [ws-caf] Mt Everest and WS-CF
> > >
> > >
> > >Alastair, I understand why you may want to revisit this, but
> > obviously
> > >disagree and don't want the TC process to be unduly stalled.
> > I cannot
> > >see what adverse effect going forward with the specification as it
> > >currently stands has on any referencing specification that
> > decides not
> > >to use context by value but instead chooses context by
> > reference (and
> > >vice versa). It does neither impinges on the readability of the
> > >specification nor on the understandability IMO.
> > >
> > >I re-iterate that I believe we have already discussed this
> > subject over
> > >the past 2/3 months in teleconferences and face-to-face meetings. I
> > >don't believe that revisiting it will benefit us or the WS-Context
> > >specification at this stage. What it will do is delay the
> > adoption of
> > >WS-Context by other interested groups and by other referencing
> > >specifications (e.g., WS-CF). I see that as a big disadvantage.
> > >
> > >Mark.
> > >
> > >----
> > >Mark Little,
> > >Chief Architect, Transactions,
> > >Arjuna Technologies Ltd.
> > >
> > >www.arjuna.com
> > >
> > >----- Original Message -----
> > >From: Green, Alastair J. <mailto:Alastair.Green@choreology.com>
> > >To: Mark Little <mailto:mark.little@arjuna.com>  ; ws-caf
> > ><mailto:ws-caf@lists.oasis-open.org>
> > >Sent: Thursday, May 27, 2004 11:28 AM
> > >Subject: [ws-caf] Mt Everest and WS-CF
> > >
> > >Hi Mark,
> > >
> > >You pointed the list at an interesting document by Savas et al. I
> > >commented upon it, as did Peter upon the interop demo, because it
> > >illustrates a fundamental issue for any potential user of
> > WS-CAF: what
> > >is the worth of WS-Context context-by-value?
> > >
> > >The argument for this feature seems to resemble the motivation for
> > >climbing Mt Everest: "because it's there".
> > >
> > >I don't think that this question can be circumvented, and it is
> > >relevant to WS-CF. Should WS-CF have a necessary dependency on
> > >WS-Context? After all, WS-Coordination manages to create a generic
> > >tree-building
> > >(address-exchange) protocol without use of a layer like WS-Context. I
> > >think this is a better model. Then those who wish to wrap context
> > >information in standard wrappers can do so (use WS-Context),
> > and those
> > >who don't wish to do so, don't need to (ignore WS-Context as adding
> > >little real value).
> > >
> > >My interest in this is far from academic. If WS-CAF transaction or
> > >coordination protocols gain traction at some future date,
> > then I would
> > >like to make our engineers' lives as easy as possible, by
> > streamlining
> > >the work needed to the strictly necessary (after all, it
> > will only be
> > >the third set of two-phase outcome protocols we have to add to our
> > >product, in order to accommodate the jostling of the
> > software industry
> > >majors). I cannot see how WS-Context contributes to WS-CF or WS-TXM.
> > >
> > >Incidentally, I made no mention of context by reference. I
> > view this as
> > >an interesting possibility fraught with problems, which I
> > predict will
> > >not be widely used. Every example of WS-Context use that I see
> > >discussed uses "by value". I certainly think that coordination
> > >protocols need by-value contexts (which of course can be carried in
> > >SOAP headers directly).
> > >
> > >Alastair
> > >
> > >-----Original Message-----
> > >From: Mark Little [mailto:mark.little@arjuna.com]
> > >Sent: 27 May 2004 10:20
> > >To: Green, Alastair J.; ws-caf
> > >Subject: Re: [ws-caf] interesting document
> > >
> > >Alastair, is this interesting for a purely academic standpoint? I
> > >believe that the TC already discussed these issues and voted
> > on them,
> > >so it seems like going back over old stuff to me. To summarise what
> > >this TC already agreed on, since we neither mandate context-by-value
> > >nor context-by-reference in the base-line context document,
> > it is up to
> > >referencing specifications to determine which format they
> > wish to use.
> > >I think that arguing this again is not going to be fruitful and I'd
> > >like to see this TC move on to the coordination specification (which
> > >was agreed at New Orleans).
> > >
> > >Mark.
> > >
> > >----
> > >Mark Little,
> > >Chief Architect, Transactions,
> > >Arjuna Technologies Ltd.
> > >
> > >www.arjuna.com
> > >----- Original Message -----
> > >From: Green, Alastair J. <mailto:Alastair.Green@choreology.com>
> > >To: Mark  <mailto:mark.little@arjuna.com> Little ; ws-caf
> > ><mailto:ws-caf@lists.oasis-open.org>
> > >Sent: Wednesday, May 26, 2004 6:03 PM
> > >Subject: RE: [ws-caf] interesting document
> > >
> > >I have to believe I'm missing something or being plain
> > stupid, but here
> > >goes ...
> > >
> > >It would be interesting, in light of Peter's recent mail on
> > the value
> > >of WS-Context context-by-value, to examine what would change
> > in these
> > >scenarios if the <ctx:context/> were to be replaced by a simple SOAP
> > >header element. Strip out <ctx:context/>, replace the placeholder
> > >"context state" with <protocol:context/>, place this element in the
> > >SOAP header, and proceed. This would be a less restrictive, but I
> > >believe legal, use of WS-I (i.e. move protocol-specific context info
> > >from body to header).
> > >
> > >It would also be interesting to consider, in the light of
> > Jim and Guy's
> > >exchanges, what role activity completion plays, if any? Activity
> > >completion can only be communicated to context recipients if
> > they are
> > >registered with the context service that knows that the
> > activity is now
> > >complete. WS-Context does not define such a
> > registration-notification
> > >mechanism. This continues to leave in question the
> > independent value of
> > >WS-Context context-by-value. This type of functionality must
> > reside in
> > >the surrounding protocol (session, coordination etc) that in
> > my example
> > >is denoted by the namespace URI indicated by the prefix
> > "protocol" (the
> > >"referencing specification"). An example of such a protocol
> > is WS-CF,
> > >or in truncated form, WS-Coordination.
> > >
> > >As there is no bundle of contexts specified by WS-Context (if my
> > >understanding has kept pace with the spec changes), the
> > argument that
> > >value is provided by easing interception (simpler to
> > identify the group
> > >of contexts that must be processed by a set of
> > interceptors), becomes a
> > >non-argument.
> > >
> > >Where does this leave the independent value of WS-Context
> > >context-by-value?
> > >
> > >These points are orthogonal to the issue: header element in the raw,
> > >body element in the raw, or element embedded in an address.
> > >
> > >Alastair
> > >-----Original Message-----
> > >From: Mark Little [mailto:mark.little@arjuna.com]
> > >Sent: 26 May 2004 16:45
> > >To: ws-caf
> > >Subject: [ws-caf] interesting document
> > >http://forge.gridforum.org/projects/dais-wg/document/draft-gg
> f-dais-map
> >p
> >ings-ggf11/en/1
> >
> >And Savas is a member of this TC (though I don't think he's ever
> >attended any of the teleconferences ;-)
> >
> >Mark.
> >
> >----
> >Mark Little,
> >Chief Architect, Transactions,
> >Arjuna Technologies Ltd.
> >
> >www.arjuna.com
> >
> >
> >
>
>