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RE: Another way of thinking about EPRs

From: Srinivas, Davanum M <Davanum.Srinivas@ca.com>
Date: Fri, 10 Dec 2004 12:55:58 -0500
Message-ID: <87527035FDD42A428221FA578D4A9A5B0890829D@usilms24.ca.com>
To: "Christopher B Ferris" <chrisfer@us.ibm.com>
Cc: "Martin Gudgin" <mgudgin@microsoft.com>, <public-ws-addressing@w3.org>

Some please tell me that there is not even one valid scenario and I'll
shut up :) 

I was told that "annotation" of Refps on the wire has come up several
times in the past in various forums even before addressing got to this
WG. So I know am not being a fool. And so far I haven't seen a reason
why *NOT* to do it. Rich said it may be harder to sign stuff if we use
attributes as annotation [1], Chris said that it is technically possible
[2], nothing other than that. We may just be not have found the right
solution on how to do it. If this is the case, then please let be clear
about THAT. Having said that, I know we need a much **stronger** reason
to add something to the spec rather than just my fancy wish....So please
help to come up with a use case that we can agree is valid.

So I ask again, - Is there consensus on whether we need some
"annotation"? (could be wrappers, could be attributes, could be
something else entirely). 

If there is none, then we can stop wasting time and bandwidth on this
issue. 

Thanks,
dims 

[1]
http://lists.w3.org/Archives/Public/public-ws-addressing/2004Dec/0074.ht
ml
[2]
http://lists.w3.org/Archives/Public/public-ws-addressing/2004Nov/0563.ht
ml

-----Original Message-----
From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Srinivas,
Davanum M
Sent: Friday, December 10, 2004 9:32 AM
To: Christopher B Ferris
Cc: Martin Gudgin; public-ws-addressing@w3.org
Subject: RE: Another way of thinking about EPRs


Let's take this use case then, Assuming that i am indeed using "refps
exclusively for application of the WS-RF implied resource pattern"
[possibly for monitoring a Grid environment, log into a web site, get an
EPR emailed to you, then use that EPR to access a grid service????].
wsa:To, wsa:From, wsa:MessageID, wsa:RelatesTo does not tell me which
resource is being used and I cannot collect aggregate statistics on how
many times it was used. And also assume that services are being added to
the grid on a dynamic basis (which means that I cannot keep entering all
Qname's of all possible RefProperties by hand). I want to do this
transparently and show a neat and nice UI with all resources
(automatically discovered, keyed by Address+ReferenceProperties) and
statistics about each resource.

Is this a valid use of WS-Addressing/EPR's/RefP's? or it is too
outland-ish?

-- dims

-----Original Message-----
From: Christopher B Ferris [mailto:chrisfer@us.ibm.com]
Sent: Friday, December 10, 2004 9:02 AM
To: Srinivas, Davanum M
Cc: Martin Gudgin; public-ws-addressing@w3.org;
public-ws-addressing-request@w3.org
Subject: RE: Another way of thinking about EPRs

Dims,

You wrote:
>Section 2.4 of submission[1] talks about  comparing 2 EPR's. If I have 
>to write a completely transparent BPEL or  WS-Choreography monitoring 
>solution, I need to be able to look at the  wire and be able to figure 
>out who is talking to who and keep track of  interactions between 
>entities in the system. *IF* from the soap message  on the wire I can 
>figure out the "who" portion..then I am all set.

Again, I must ask; why aren't <wsa:To/> and <wsa:From/> sufficient to
achieve this objective? 

I could be using the refps for applying the implied resource pattern
(WS-RF), but that is not a required application of refps. Does your
monitoring of SOAP traffic have intimate knowledge about PONumber
embedded in the soap:Body? I doubt it would be even remotely practical
as it would require domain knowledge of all application-domains on the
part of the monitoring software.
Yet, a soap:Body//PONumber identifies a resource relevant to the service
just as a refp might do.

Bottom line, what is the "who" you think you are tracking? The
resource(s) behind a service endpoint or the service itself? If the
former, then frankly, unless refps are used exclusively for application
of the WS-RF implied resource pattern, you are probably making a false
assumption.

If you are tracking for purposes of matching requests with responses,
then you have wsa:MessageId and wsa:RelatesTo. The address becomes
immaterial. 

Cheers,

Christopher Ferris
STSM, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
blog: http://webpages.charter.net/chrisfer/blog.html
phone: +1 508 377 9295

public-ws-addressing-request@w3.org wrote on 12/09/2004 10:13:24 PM:

> 
> Martin, All,
> 
> Yes, I get it...Here's a variation of the argument I have been making 
> for i008 (not sure about i001). Section 2.4 of submission[1] talks 
> about comparing 2 EPR's. If I have to write a completely transparent 
> BPEL or WS-Choreography monitoring solution, I need to be able to look

> at the wire and be able to figure out who is talking to who and keep 
> track of interactions between entities in the system. *IF* from the 
> soap message on the wire I can figure out the "who" portion..then I am
all set.
> According to 2.4, I can use the combination of [address] and 
> [reference properties] to figure out A is sending the message to B.
> BUT if I don't have access to the EPR's themselves or list of all the 
> Qname's that are definitely reference properties, I cannot find out 
> the "who". IF there is some "annotation" (word used by Jonathan on
> IRC) on the soap message on the wire then I can do this VERY easily.
> 
> So the basic question is - Is there consensus on whether we need some 
> "annotation"? (could be wrappers, could be attributes, could be 
> something else entirely).
> 
> [1] http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/
> 
> Thanks,
> dims
> 
> -----Original Message-----
> From: public-ws-addressing-request@w3.org
> [mailto:public-ws-addressing-request@w3.org] On Behalf Of Martin 
> Gudgin
> Sent: Thursday, December 09, 2004 6:47 PM
> To: public-ws-addressing@w3.org
> Subject: Another way of thinking about EPRs
> 
> 
> I've noticed that whenever we talk about issues i001 and i008, that 
> there is an implicit assumption that we start with an EPR and go from 
> that to the message. I think that in many cases, the reverse is 
> actually true, that is, people start with SOAP messages with headers 
> in and then decide how to communicate to a potential sender what those

> messages should look like ( WRT the headers ).
> 
> For example, I want to have people send me messages that look like the

> three below.
> 
> <soap:Envelope>
>  <soap:Header>
>    <wsa:To>http://example.org/weather</wsa:To>
>    <m:ServiceLevel>Gold</m:ServiceLevel>
>    <m:TxId>1234</m:TxId>
>  </soap:Header>
>  <soap:Body>
>  . . .
>  </soap:Body>
> </soap:Envelope>
> 
> <soap:Envelope>
>  <soap:Header>
>    <wsa:To>http://example.org/weather</wsa:To>
>    <m:ServiceLevel>Silver</m:ServiceLevel>
>    <m:TxId>1234</m:TxId>
>  </soap:Header>
>  <soap:Body>
>  . . .
>  </soap:Body>
> </soap:Envelope>
> 
> <soap:Envelope>
>  <soap:Header>
>    <wsa:To>http://example.org/weather</wsa:To>
>    <m:ServiceLevel>Gold</m:ServiceLevel>
>    <m:TxId>4567</m:TxId>
>  </soap:Header>
>  <soap:Body>
>  . . .
>  </soap:Body>
> </soap:Envelope>
> 
> How can I communicate to my users that I want the messages to look 
> like this? Ah, I know, I'll send them an EPR. Here are the three EPRs 
> for the messages above ( my seperation between Props/Params is
arbitrary ).
> 
> <wsa:EndpointReference>
>  <wsa:Address>http://example.org/weather</wsa:Address>
>  <wsa:ReferenceProperties>
>   <m:ServiceLevel>Gold</m:ServiceLevel>
>  </wsa:ReferenceProperties>
>  <wsa:ReferenceParameters>
>   <m:ServiceLevel>1234</m:ServiceLevel>
>  </wsa:ReferenceParameters>
> </wsa:EndpointReference>
> 
> <wsa:EndpointReference>
>  <wsa:Address>http://example.org/weather</wsa:Address>
>  <wsa:ReferenceProperties>
>   <m:ServiceLevel>Silver</m:ServiceLevel>
>  </wsa:ReferenceProperties>
>  <wsa:ReferenceParameters>
>   <m:ServiceLevel>1234</m:ServiceLevel>
>  </wsa:ReferenceParameters>
> </wsa:EndpointReference>
> 
> <wsa:EndpointReference>
>  <wsa:Address>http://example.org/weather</wsa:Address>
>  <wsa:ReferenceProperties>
>   <m:ServiceLevel>Gold</m:ServiceLevel>
>  </wsa:ReferenceProperties>
>  <wsa:ReferenceParameters>
>   <m:ServiceLevel>4567</m:ServiceLevel>
>  </wsa:ReferenceParameters>
> </wsa:EndpointReference>
> 
> Does this make any sense?
> 
> Gudge
> 
> 
> 
> 
Received on Friday, 10 December 2004 17:56:00 GMT

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