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Re: An Example Use of RM's MakeConnection

From: Marc Hadley <Marc.Hadley@Sun.COM>
Date: Fri, 13 Oct 2006 10:10:07 -0400
To: David Hull <dmh@tibco.com>
Cc: Doug Davis <dug@us.ibm.com>, public-ws-addressing@w3.org
Message-id: <65952A24-75BD-4831-9C99-21AD357F67C0@Sun.COM>
On Oct 12, 2006, at 11:58 PM, David Hull wrote:

> Marc Hadley wrote:
>> The message in step 2 is still a response in WS-A and SOAP binding  
>> terms.
> Actually, the more relevant question is: Is it a reply in WSA terms?
>
Section 3 of core says:

"The basic interaction pattern from which all others are composed is  
"one way". In this pattern a source sends a message to a destination  
without any further definition of the interaction. "Request Reply" is  
a common interaction pattern that consists of an initial message sent  
by a source endpoint (the request) and a subsequent message sent from  
the destination of the request back to the source (the reply). A  
reply in this case can be either an application message, a fault, or  
any other message. Note, however, that reply messages may be sent as  
part of other message exchanges as well, and are not restricted to  
the usual single Request, single Reply pattern, or to a particular  
WSDL MEP. The contract between the interacting parties may specify  
that multiple or even a variable number or replies be delivered."

Given the above I think the message in step 2 is a reply in WSA terms  
falling into the "other message" category.

> If it is, why isn't it formulated according to the rules in section  
> 3 of the core?
>
It mostly is but, looking closely, I see that I missed an additional  
wsa:RelatesTo with the standard "reply" RelationshipType.

Marc.

>>
>> On Oct 12, 2006, at 1:37 PM, David Hull wrote:
>>
>>> According to section 5 of the SOAP binding, if [reply endpoint] is
>>> anonymous, then "any response MUST be the
>>> http://www.w3.org/2003/05/soap/mep/OutboundMessage property of  
>>> the same
>>> instance of the SOAP request-response MEP".  There is no  
>>> definition of
>>> "response" in this section, but given that we define "response  
>>> endpoint"
>>> as [reply endpoint] or [fault endpoint] and lacking any other  
>>> plausible
>>> interpretation, the intent is clear: a response is a reply or a  
>>> fault.
>>>
>>> A reply MUST be formulated according to the rules in section 3.   
>>> Section
>>> 4 of the WSDL spec says that the reply message would have an  
>>> [action] of
>>> foo:GetQuoteResponse and otherwise follow the WSDL operation  
>>> description
>>> (assuming this description is WSA-aware).  In other words, the  
>>> message
>>> in step 5 is the reply.
>>>
>>> The server below is behaving incorrectly in step 2.  The [reply
>>> endpoint] of anonymous requires it to send the message it sends  
>>> in step
>>> 5 in step 2 instead.
>>>
>>>
>>> Marc Hadley wrote:
>>>> Looking at the message flow, I think WS-RM could make more use of
>>>> wsa:RelatesTo instead of inventing a new anon URI. Here's the same
>>>> message flow using the WS-A anon URI and making more use of
>>>> wsa:RelatesTo and @RelationshipType.
>>>>
>>>> I think this formulation removes the requirement for additional
>>>> WSRM-specific anon URIs, let me know if I missed anything.
>>>>
>>>> Marc.
>>>>
>>>> Scenario: Client sends GetQuote to server unreliably.  Server  
>>>> wants to
>>>> send GetQuoteResponse using RM so it must sent a CreateSequence  
>>>> before
>>>> I can send the GetQuoteResponse back.
>>>>
>>>> Step 1 - Client sends GetQuote to Server
>>>> <soap:Envelope ...>
>>>>  <soap:Header>
>>>>   <wsa:To> http://stockquote.com </wsa:To>
>>>>   <wsa:Action> foo:GetQuote </wsa:Action>
>>>>   <wsa:MessageID> uuid://.../100 </wsa:MessageID>
>>>>   <wsa:ReplyTo>
>>>>    <wsa:Address>http://www.w3.org/.../anonymous</wsa:Address>
>>>>   </wsa:ReplyTo>
>>>>  </soap:Header>
>>>>  <soap:Body>
>>>>   <foo:GetQuote> IBM </foo:GetQuote>
>>>>  </soap:Body>
>>>> </soap:Envelope>
>>>>
>>>> Step 2 - Server sends an RM CreateSequence to the Client using the
>>>> only means it has available - the transport backchannel.
>>>> <soap:Envelope ...>
>>>>  <soap:Header>
>>>>   <wsa:To>http://www.w3.org/.../anonymous</wsa:To>
>>>>   <wsa:Action> http://...wsrm/CreateSequence </wsa:Action>
>>>>   <wsa:MessageID> uuid://.../101 </wsa:MessageID>
>>>>   <wsa:RelatesTo RelationshipType="http://...wsrm/InitReliable">
>>>>     uuid://.../100
>>>>   </wsa:RelatesTo>
>>>>   <wsa:ReplyTo>
>>>>    <wsa:Address> http://stockquote.com </wsa:Address>
>>>>   </wsa:ReplyTo>
>>>>  </soap:Header>
>>>>  <soap:Body>
>>>>   <wsrm:CreateSequence> ... </wsrm:CreateSequence>
>>>>  </soap:Body>
>>>> </soap:Envelope>
>>>>
>>>> Notice the use of RelatesTo with a WSRM-specific  
>>>> @RelationshipType to
>>>> indicate that this message is a WSRM-specific response to the  
>>>> initial
>>>> request.
>>>>
>>>> Step 3 - Client sends a CreateSequenceResponse to wsa:ReplyTo
>>>> <soap:Envelope ...>
>>>>  <soap:Header>
>>>>   <wsa:To> http://stockquote.com </wsa:To>
>>>>   <wsa:Action> http://...wsrm/CreateSequenceResponse </wsa:Action>
>>>>   <wsa:RelatesTo> uuid://.../101 </wsa:RelatesTo>
>>>>  </soap:Header>
>>>>  <soap:Body>
>>>>   <wsrm:CreateSequenceResponse> ... </wsrm:CreateSequenceResponse>
>>>>  </soap:Body>
>>>> </soap:Envelope>
>>>>
>>>> Step 4 - Having not received the GetQuoteResponse, the Client uses
>>>> MakeConnection to allow it to flow back
>>>> <soap:Envelope ...>
>>>>  <soap:Header>
>>>>   <wsa:To> http://stockquote.com </wsa:To>
>>>>   <wsa:Action> http://...wsrm/MakeConnection </wsa:Action>
>>>>   <wsa:ReplyTo>
>>>>    <wsa:Address>http://www.w3.org/.../anonymous</wsa:Address>
>>>>   </wsa:ReplyTo>
>>>>   <wsa:RelatesTo RelationshipType="http://...wsrm/InitialRequest">
>>>>     uuid://.../100
>>>>   </wsa:RelatesTo>
>>>>  </soap:Header>
>>>>  <soap:Body>
>>>>   <wsrm:MakeConnection>
>>>>   </wsrm:MakeConnection>
>>>>  </soap:Body>
>>>> </soap:Envelope>
>>>>
>>>> Notice the use of the wsa:RelatesTo with a WSRM-specific
>>>> @RelationshipType to indicate that this message is requesting a
>>>> response to the initial request message.
>>>>
>>>> Step 5 - Server uses the backchannel to let the GetQuoteResponse  
>>>> flow
>>>> back to the Client
>>>> <soap:Envelope ...>
>>>>  <soap:Header>
>>>>   <wsa:To>http://www.w3.org/.../anonymous</wsa:To>
>>>>   <wsa:Action> foo://GetQuoteResponse </wsa:Action>
>>>>   <wsa:RelatesTo> uuid://.../100 </wsa:RelatesTo>
>>>>   <wsrm:Sequence> ... </wsrm:Sequence>
>>>>  </soap:Header>
>>>>  <soap:Body>
>>>>   <foo:GetQuoteResponse> 139.0 </foo:GetQuoteResponse>
>>>>  </soap:Body>
>>>> </soap:Envelope>
>>>>
>>>> Notice the wsa:RelatesTo points to the GetQuote request message  
>>>> and it
>>>> is sent using RM (the Sequence header), and that the SOAP Envelope
>>>> looks exactly like it would if it had been sent on the original
>>>> transport backchannel - meaning, the wsa:To is derived from the
>>>> wsa:ReplyTo from the GetQuote request message not the  
>>>> MakeConnection.
>>>>
>>>> ---
>>>> Marc Hadley <marc.hadley at sun.com>
>>>> Business Alliances, CTO Office, Sun Microsystems.
>>>>
>>>>
>>>
>>
>> ---
>> Marc Hadley <marc.hadley at sun.com>
>> Business Alliances, CTO Office, Sun Microsystems.
>>
>>
>

---
Marc Hadley <marc.hadley at sun.com>
Business Alliances, CTO Office, Sun Microsystems.




Received on Friday, 13 October 2006 14:10:26 GMT

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