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Re: An Example Use of RM's MakeConnection

From: David Hull <dmh@tibco.com>
Date: Thu, 12 Oct 2006 13:37:22 -0400
To: Marc Hadley <Marc.Hadley@Sun.COM>
Cc: Doug Davis <dug@us.ibm.com>, public-ws-addressing@w3.org
Message-id: <452E7D52.1010309@tibco.com>

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.
>
>
Received on Thursday, 12 October 2006 17:39:16 GMT

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