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RE: [issue 6432] - a modest proposal

From: Geoff Bullen <Geoff.Bullen@microsoft.com>
Date: Fri, 15 May 2009 16:03:38 -0700
To: Doug Davis <dug@us.ibm.com>
CC: Gilbert Pilz <gilbert.pilz@oracle.com>, "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Message-ID: <5AAAA6322448AA41840FC4563A30D6E847589D2DA0@NA-EXMSG-C122.redmond.corp.microsoft.com>

> Its only easy and works in the most simple, basic, non-extensbile, limiting, non-future-looking, put-your-customer-into-a-tiny-box-and-throw-away-the-key cases.

Doug,
I assume the above comment is directed at the many partners who have successfully implemented, tested and interop'ed with Eventing (using mode) in the real world, using the scenarios they require to do business.  There are currently 100's of different implementations and millions of users successfully using Eventing with "mode".  There is no justification for any of the above statements.

To turn things around, how many implementations of your proposed method for Eventing are there at present?  How much interop testing has there been?  Where is the proof that your proposal works in an interoperable way for Eventing scenarios?

BTW: No one is suggesting that RM should be a mode, Doug.

Regards,
Geoff


From: Doug Davis [mailto:dug@us.ibm.com]
Sent: Thursday, May 14, 2009 5:47 PM
To: Geoff Bullen
Cc: Gilbert Pilz; public-ws-resource-access@w3.org
Subject: RE: [issue 6432] - a modest proposal


> Mode allows a way to "select" from among a set of conflicting alternatives easily

Its only easy and works in the most simple, basic, non-extensbile, limiting, non-future-looking, put-your-customer-into-a-tiny-box-and-throw-away-the-key cases.  :-)

Take your example and pretend that WS-RM was invented after "Blue" Mode URI and people want to use it with the Blue Mode. If both sides support RM it should work right?  Nope, using your method it won't because no one has defined a new Mode URI.  This gets back to one of my biggest problems with Mode, its not scalable or composible unless there's some governing authority willing to define all possible Mode URIs for all possible combinations of extensions.  Not gonna happen - or if it does I pitty the people who will be willing to wait for that "totally non-political body"  to ever agree on which combinations are "valid".  ha!  Which means people who use Mode will either be stuck with a pre-canned list of URIs/features that will never be extended in any timely fashion, or everyone will develop their own set of URIs and we'll have no interop.  Neither of which is very appealing.

Any new feature/extension will (or should) define something like Policy so it can be advertised, this means that it'll automatically work with any WS* spec that uses Policy to indicate what's supported.  This means that this new feature will automatically be able to be used with WS-E.  Back to the RM example - that TC is closed, who will define the Mode URI to indicate that RM should be used to send the Notifications? Or that it can be composed with Wu's Proxy feature? Or that RM can be composed with anything?  Its an interop and usability nightmare waiting to happen.

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com
The more I'm around some people, the more I like my dog.

Geoff Bullen <Geoff.Bullen@microsoft.com>

05/14/2009 07:53 PM

To

Gilbert Pilz <gilbert.pilz@oracle.com>

cc

Doug Davis/Raleigh/IBM@IBMUS, "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>

Subject

RE: [issue 6432] - a modest proposal







Thanks for your feedback Gil,

> By your definition below ("The event source has only validated (via interop testing) two possible combinations: A,B,C and A,B,D") the above would be an invalid request.

Yes it would be invalid, but it would also be an impossible request to make if you used mode, since mode only allows you to specify one such option in a message.  So one of the things that mode provides is an easy mechanism to support mutually conflicting alternatives.  If you add optional elements (options available to all modes) to the mix it gets even more complicated. Without mode, the code itself will need to work out what options have been specified, determine if they are conflicting and if so cause some kind of new fault ("conflicting options?") to occur.
Mode allows a way to "select" from among a set of conflicting alternatives easily.

--Geoff

From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com]
Sent: Thursday, May 14, 2009 12:10 PM
To: Geoff Bullen
Cc: Doug Davis; public-ws-resource-access@w3.org
Subject: Re: [issue 6432] - a modest proposal

Comments inline . . .

On 5/13/2009 2:46 PM, Geoff Bullen wrote:
Gil,
So what would this mean:

Example 1)
Header]
<som:UseBlue mustUnderstand="1"/>
<som:UseRed mustUnderstand="1"/>

[Body]
<wse:Subscribe>
 <wse:NotifyTo>{some EPR}</wse:NotifyTo>
 <som:Blue/>
  <som:Red/>
</wse:Subscribe>
It depends upon the semantics defined by the authors of the Red and Blue extensions. By your definition below ("The event source has only validated (via interop testing) two possible combinations: A,B,C and A,B,D") the above would be an invalid request.

And is the above different to:
Example 2)
Header]
<som:UseBlue mustUnderstand="1"/>
<som:UseRed mustUnderstand="1"/>

[Body]
<wse:Subscribe>
 <wse:NotifyTo>{some EPR}</wse:NotifyTo>
</wse:Subscribe>
Again it depends upon how the extension authors defined these extensions. If the extension is indicated solely by the presence of som:Blue or som:Red in the Subscribe request, then the above request is different in that it has not been extended. I would note that the creator of this request is being foolish in that they are indicating that the receiver must understand two extensions, neither of which are are actually needed to process the request.

- gp



Thanks,
Geoff

From: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org> [mailto:public-ws-resource-access-request@w3.org] On Behalf Of Gilbert Pilz
Sent: Tuesday, May 12, 2009 4:32 PM
To: Geoff Bullen
Cc: Doug Davis; public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Subject: Re: [issue 6432] - a modest proposal

Geoff,

Not at all. The equivalent w/out mode would be:

[Header]
<som:UseBlue mustUnderstand="1"/>

[Body]
<wse:Subscribe>
 <wse:NotifyTo>{some EPR}</wse:NotifyTo>
 <som:Blue/>
</wse:Subscribe>

There's no reason why my extensions have to be atomic while your extensions get to be collections. That's an orthogonal consideration that has nothing to do with the use or non-use of Mode.

- gp

On 5/12/2009 4:13 PM, Geoff Bullen wrote:
Gil,
It is not just a simple case of comparing XML, but let's start here...

Using the RED/BLUE example discussed below...

Using mode, we send:

[Body]
<Subscribe>
  <Delivery mode=".../BLUE">
    <NotifyTo>  ... </NotifyTo>
  </Delivery>
</Subscribe>

The equivalent without mode would be:

[Header]
<UseA mustUnderstand="1"/>
<UseB mustUnderstand="1"/>
<UseD mustUnderstand="1"/>

[Body]
<Subscribe>
  <NotifyTo>  ... </NotifyTo>
  <A />
  <B />
  <D />
</Subscribe>

Maybe some of the A, B, D elements are actually inside the NotifyTo EPR, but it does not matter for this discussion.

--Geoff


From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com]
Sent: Tuesday, May 12, 2009 1:08 PM
To: Geoff Bullen
Cc: Doug Davis; public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Subject: Re: [issue 6432] - a modest proposal

Geoff,

As I said before, please show me a specific message (in XML) using Mode. I will show you the same message without Mode. We can then compare and contrast.

- gp

On 5/12/2009 9:57 AM, Geoff Bullen wrote:
Thanks Gil,

Based on the information below, let us look at the following example:

The event source has implemented four different extensibility points A, B, C, D.
The event source has only validated (via interop testing) two possible combinations: A,B,C and A,B,D.
These are the only two combinations supported by the event source.

If mode is used, one can easily create two modes RED = A,B,C and BLUE = A,B,D and the client can simply send this mode, along with any required information, to the event source for processing.

Without mode, there are a number of interesting situations:
What if the client does not send mU headers and sends elements A,B,C,D? ( Can you ignore some of them?)
What if the client does send mU headers and sends elements A,B,C,D?  (Does must understand = must use?)
What if B required no information to be sent from the client to the event source (only the fact that the client wants to use B)?  Does that mean you would have to create an empty element B, just to send something?  Or use an mU header?  Using mode, both RED and BLUE infer B, no need to send an empty element at all.
The event source, without mode, now seems to have a much more complicated task of trying to figure out if the client wants RED, BLUE or if it's a fault situation - illegal combination?  For example, without mode, the combination A,B would have to be seen as illegal.  With mode = RED, the event server could use the default values for C and proceed.
Without mode, would the combination B,C be legal or illegal?
Think of the documentation that the event source will generate in order for the client to understand what is supported.  It will almost certainly talk about RED mode and BLUE mode and point out what is required to support both.  The natural extension to this is for the client to simply select RED or BLUE when doing the subscribe.
Gets more complicated if A is only a partial implementation and A (with one setting) supports RED and A (with a different setting) supports BLUE.
There are probably more...

The point is, as has been stated many times, you can always find a way to solve any problem with any of the solutions proposed, but some solutions are better at handling certain situations than others.  Mode is better at handling grouping cases where there is a small number of supported configurations which contain groups of characteristics.  Other ways are better at handling the opposite case, where the event source supports a variety of characteristics that can be combined in different ways.  It seems that we should support both options.

--Geoff

From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com]
Sent: Monday, May 11, 2009 5:25 PM
To: Geoff Bullen
Cc: Doug Davis; public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Subject: Re: [issue 6432] - a modest proposal

Geoff,

I believe I can speak for those of us who would like to eliminate the Delivery element and the Mode attribute.

1.) Use the extensibility that already exists in Subscribe and the various EPRs to express your extensions. For example, request an extension by adding a child element to Subscribe.

2.) If necessary (and it's important to note that it is not always necessary), accompany the extension with a SOAP mU header that indicates that an extension is being used.

3.) Use WS-Policy assertions to indicate which extensions are supported by an Event Source. These policies assertions can be attached to WSDLs and retrieved by the normal mechanisms for obtaining a WSDL (HTTP, WS-Mex), or they may be retrieved directly via WS-MEX, or they may be retrieved via some other mechanism.

- gp

On 5/11/2009 12:02 PM, Geoff Bullen wrote:
Doug,
Can we quickly cover what your proposed solution to replace mode really is at the moment, please?
Is it:
Use extensions to EPR and Subscribe and mU headers?  Remember that Mode should fault if it is not a valid mode, so mU would be the thing that allows that functionality.
Use runtime policy negotiation with the policy statements in the NotifyTo EPR.
Some combination of the two approaches.
I am kind of assuming it's a) but I want to make sure before I comment further.
Thanks,
Geoff

From: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org> [mailto:public-ws-resource-access-request@w3.org] On Behalf Of Doug Davis
Sent: Saturday, May 09, 2009 10:35 AM
To: public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Subject: Re: [issue 6432] - a modest proposal


This might be true if someone could show why the proposed solution doesn't work for both.  To date, the only consistent complaint about the proposal is that is may require some code changes.  I believe Gil even proposed a challenge [1] to address this type of concern - sadly, no one has taken him up on it.

[1] http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Apr/0135.html

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com<mailto:dug@us.ibm.com>
The more I'm around some people, the more I like my dog.



Bob Freund <bob@freunds.com><mailto:bob@freunds.com>
Sent by: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org>

05/07/2009 08:42 PM


To

Yves Lafon <ylafon@w3.org><mailto:ylafon@w3.org>

cc

David Snelling <David.Snelling@UK.Fujitsu.com><mailto:David.Snelling@UK.Fujitsu.com>, Gilbert Pilz <gilbert.pilz@oracle.com><mailto:gilbert.pilz@oracle.com>, Asir Vedamuthu <asirveda@microsoft.com><mailto:asirveda@microsoft.com>, Doug Davis/Raleigh/IBM@IBMUS, "public-ws-resource-access@w3.org"<mailto:public-ws-resource-access@w3.org> <public-ws-resource-access@w3.org><mailto:public-ws-resource-access@w3.org>

Subject

Re: [issue 6432] - a modest proposal











There seems like there is a big-systems use of notification as well as
a small-device market for the same protocol.
The difference seems to be the extent to which negotiation protocols
and additional features might be available.
It sounds like finding a way like this to make both ways possible
might be what is needed.
-bob

On May 6, 2009, at 4:19 PM, Yves Lafon wrote:

> On Thu, 9 Apr 2009, Bob Freund wrote:
>
>> Would it be too bold to suggest folks consider to move NotifyTo to
>> be a child of Subscribe?
>> that way, then Delivery could be used (as an xs:Any) extension
>> point, used by other specifications to mean anything they want at
>> at cost of merely setting a SOAP mU header on delivery to get the
>> fault behavior.  Of course, the fault would change from
>> modeNotRecognized to SOAP mU Fault, but the other stuff would still
>> work.
>> Is that half-way-ish approach that folks could consider?
>
> The main issue is still the addition of the mU in the default version.
> How about adding a specific mode (like 'anonymous') that would
> trigger the use of the other approach.
> That way we would have the "historic" use of mode, and the new
> version using the same trigger mechanism, allowing old
> implementation to interoperate with newer ones, while keeping a way
> to use the new version in all the cases where the old version would
> not be optimal.
> Would that make sense for both camp ?
>
>>
>> On Apr 9, 2009, at 11:09 AM, David Snelling wrote:
>>
>>> Folks,
>>> I will try this with colour:
>>> <s:Envelope . . .>
>>> <s:Header>
>>>   <wsa:Action>http://www.w3.org/2009/02/ws-evt/Subscribe<wsa:Action>
>>>   <wsa:MessageID>uuid:d7c5726b-de29-4313-b4d4-b3425b200839</
>>> wsa:MessageID>
>>>   <wsa:ReplyTo>
>>>     <wsa:Address>http://www.w3.org/2005/08/addressing/anonymous</
>>> wsa:Address>
>>>   </wsa:ReplyTo>
>>>   <wsa:To>http://www.example.org/oceanwatch/EventSource</wsa:To>
>>> </s:Header>
>>> <s:Body>
>>>   <wse:Subscribe>
>>>     <wse:Delivery>
>>>       <wse:NotifyTo>
>>>         <wsa:Address>http://www.w3.org/2005/08/addressing/
>>> anonymous</wsa:Address>
>>>       </wse:NotifyTo>
>>>     </wse:Delivery>
>>>   </wse:Subscribe>
>>> </s:Body>
>>> </s:Envelope>
>>> Red: General SOAP layer.
>>> Green: WSE Application Layer.
>>> Blue: WS-Addressing infrastructure.
>>> OK the important point is that no matter what delivery model I
>>> want to use, I only change blue and red text. The beauty of
>>> Eventing is that the green XML stays the same across all the use
>>> cases we have discussed.
>>> For wse:Push: In the blue NotifyTo EPR include a sensible address.
>>> For wsman:PushWithAck: In the blue NotifyTo EPR include an address
>>> and possibly policy indicating reliable delivery required. This
>>> will means some more stuff will show up in red and possibly orange
>>> (for the reliable messaging) on the delivered messages.
>>> For wsman:Pull: In blue include either an MC special URI or the
>>> actual address of a WS-Notification Pull point.
>>> For wsman:Events: This is the same as wsman:PushWithAck which
>>> affects only the blue, red, and orange XML, but using a format
>>> provided by WS-Management V2.0 in some pink XML.
>>> Notice: No Green XML changes!!!
>>> In fact existing implementations have to change NOTHING in their
>>> semantics. They will need to understand the new namespace and
>>> learn not to look for the Mode attribute. The semantics of
>>> Eventing do not change.
>>> On 08 Apr 2009, at 20:08, Gilbert Pilz wrote:
>>>> I think that, in this context, the term "opaque" might be a red-
>>>> herring. The point is that a URI like "http://docs.oasis-open.org/ws-rx/wsmc/200702/anonymous?id=1447d9c0-246a-11de-8c30-0800200c9a66
>>>> " requires neither more nor less understanding at the application
>>>> layer (in this case the component that processes wse:Subscribe
>>>> requests) than a URI like "http://www.w3.org/2005/08/addressing/anonymous
>>>> " or "http://webservice.bea.com/ohai/lolcatz"<http://webservice.bea.com/ohai/lolcatz>.
>>>> I think part of the problem might be that we are all assuming
>>>> different processing models. Look at the following request and
>>>> tell me how you think it should be handled. If you could be
>>>> somewhat specific about which layer (ws-addr layer, general SOAP
>>>> layer, wse:Subscribe logic, etc.) does/checks what, that would be
>>>> helpful:
>>>> <s:Envelope . . .>
>>>> <s:Header>
>>>>   <wsa:Action>http://www.w3.org/2009/02/ws-evt/
>>>> Subscribe<wsa:Action>
>>>>   <wsa:MessageID>uuid:d7c5726b-de29-4313-b4d4-b3425b200839</
>>>> wsa:MessageID>
>>>>   <wsa:ReplyTo>
>>>>     <wsa:Address>http://www.w3.org/2005/08/addressing/anonymous</
>>>> wsa:Address>
>>>>   </wsa:ReplyTo>
>>>>   <wsa:To>http://www.example.org/oceanwatch/EventSource</wsa:To>
>>>> </s:Header>
>>>> <s:Body>
>>>>   <wse:Subscribe>
>>>>     <wse:Delivery>
>>>>       <wse:NotifyTo>
>>>>         <wsa:Address>http://www.w3.org/2005/08/addressing/
>>>> anonymous</wsa:Address>
>>>>       </wse:NotifyTo>
>>>>     </wse:Delivery>
>>>>   </wse:Subscribe>
>>>> </s:Body>
>>>> </s:Envelope>
>>>> - gp
>>>> Yves Lafon wrote:
>>>>> On Tue, 7 Apr 2009, Gilbert Pilz wrote:
>>>>>> WS-Addressing 1.0 - Core defines two "special" URIs;
>>>>>> "http://www.w3.org/2005/08/addressing/anonymous"<http://www.w3.org/2005/08/addressing/anonymous> and
>>>>>> "http://www.w3.org/2005/08/addressing/none"<http://www.w3.org/2005/08/addressing/none>. Messages targeted
>>>>>> to either
>>>>>> of these URIs are processed differently from messages targeted to
>>>>>> "normal" URIs such as "http://webserivce.bea.com/. . ."<http://webserivce.bea.com/...>.
>>>>> Well, they are different, but unless you know WS-Addressing, or
>>>>> unless you resolve http://www.w3.org/2005/08/addressing/
>>>>> anonymous and find out the relationship between this URI and the
>>>>> WS-Addressing spec.
>>>>> If you resolve http://webservice.bea.com/... you will probably
>>>>> have information about the endpoint, or you may know it in
>>>>> advance from another document. So both URIs are opaque, unless
>>>>> you know their semantic.
>>> Take care:
>>>
>>>   Dr. David Snelling < David . Snelling . UK . Fujitsu . com >
>>>   Fujitsu Laboratories of Europe Limited
>>>   Hayes Park Central
>>>   Hayes End Road
>>>   Hayes, Middlesex  UB4 8FE
>>>   Reg. No. 4153469
>>>
>>>   +44-7590-293439 (Mobile)
>>> ______________________________________________________________________
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>>> Registered No. 4153469
>>> This e-mail and any attachments are for the sole use of
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>>
>
> --
> Baroula que barouleras, au tiéu toujou t'entourneras.
>
>        ~~Yves
>
>
Received on Friday, 15 May 2009 23:04:26 GMT

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