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Subject: Re: [ws-rx] Proposal for i012
Isn't this conflating a reply with an Ack? Which can be different. I tend to agree with Marc's view that you are pointing to a scenario where anon AcksTo cannot be used -- in which case don't use it. I hope I'm not missing some subtlety that you are getting at. But there is another issue (which perhaps needs to be raised separately): what 'anon' address means for AcksTo EPR is not defined anywhere. WS-Addressing Core [1] and section 2.1 says the following about 'anon': "Some endpoints cannot be located with a meaningful IRI; this URI is used to allow such endpoints to send and receive messages. The precise meaning of this URI is defined by the binding of Addressing to a specific protocol." WS-Addressing SOAP binding [2] defines what the 'anon' address means when used with ReplyTo and FaultTo in SOAP and SOAP/HTTP binding. It does not say anything about what it means when used in other headers such as AcksTo. This is easily fixed by adding a stmt similar to WS-Addressing SOAP binding. Something like: "When "http://www.w3.org/2005/08/addressing/anonymous"; is specified as the address of the wsrm:AcksTo EPR, the underlying SOAP protocol binding provides a channel to the specified endpoint. Any underlying protocol binding supporting the SOAP request-response message exchange pattern provides such a channel. For instance, the SOAP 1.2 HTTP binding[SOAP 1.2 Part 2: Adjuncts] puts the reply message in the HTTP response." OR we could ask the WS-Addressing WG to fix their SOAP binding to include not just ReplyTo and FaultTo EPRs but any EPR when used in the context of SOAP/HTTP binding. Thoughts? -Anish -- [1] http://www.w3.org/TR/2005/CR-ws-addr-core-20050817/ [2] http://www.w3.org/TR/2005/CR-ws-addr-soap-20050817/ Lei Jin wrote: > I probably should explain this better. I am proposing that an > AckRequested block can be sent standalone in the message body. In this > case, it is a request/response message. And a SequenceAcknowledgement > is sent in response to this message. If you specify an anonymous URI > for the ReplyTo of the AckRequested message, then the > SequenceAcknowledgement can be sent back on the http response channel. > > I guess we could use a different message element than AckRequested, but > I was just trying to reuse an existing construct. > > Lei > > >>-----Original Message----- >>From: Christopher B Ferris [mailto:chrisfer@us.ibm.com] >>Sent: Thursday, August 25, 2005 1:59 PM >>To: Lei Jin >>Cc: Anish Karmarkar; Marc Goodner; ws-rx@lists.oasis-open.org >>Subject: RE: [ws-rx] Proposal for i012 >> >> >>Lei, >> >>AckRequested is not request/response. I don't see how this >>helps at all. >> >>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 >> >>"Lei Jin" <ljin@bea.com> wrote on 08/25/2005 03:12:13 PM: >> >> >>>A request-response MEP used reliably is asynchronous and is >> >>basically >> >>>composed of two separate one-way MEPs. Thus, there are really no >>>differences to the oneway case. (there is nothing normally flowing >>>back on the http response) >>> >>>If there is an AcksTo address on the source side that is >> >>reachable from >> >>>the destination, then use that address. Otherwise, use >> >>the not-allowed >> >>>EPR for AcksTo which means you can retrieve the Acks through >>>AcksRequest messages. >>> >>>Lei >>> >>> >>>>-----Original Message----- >>>>From: Anish Karmarkar [mailto:Anish.Karmarkar@oracle.com] >>>>Sent: Thursday, August 25, 2005 10:24 AM >>>>To: Lei Jin >>>>Cc: Marc Goodner; ws-rx@lists.oasis-open.org; Christopher B Ferris >>>>Subject: Re: [ws-rx] Proposal for i012 >>>> >>>> >>>>Hi Lei, >>>> >>>>How does your proposal address the scenario where: >>>>HTTP is being used, there aren't any intermediaries, it is a >>>>request-response WSDL MEP, and the acks are to be sent >> >>using the HTTP >> >>>>response (backchannel). >>>> >>>>In such a case, what should the value of the [address] property of >>>>AcksTo EPR be? >>>> >>>>-Anish >>>>-- >>>> >>>>Lei Jin wrote: >>>> >>>>>I disagree. Here is a use case that shows a problem with >>>> >>>>an anonymous >>>> >>>>>AcksTo. >>>>> >>>>>Node A ---> Intermediary ---> Node B >>>>> >>>>>Node A tries to send messages reliably to Node B. For >> >>simplicity, >> >>>>>let's >>>>>assume these are all oneway messages. Node A establishes a >>>> >>>>reliable >>>> >>>>>sequence with an anonymous AcksTo and starts to send messages. >>>>>The >>>>>messages first go through the Intermediary which has >> >>B's WSDL and >> >>>>>figures out these are oneway messages. So it decides to >>>> >>>>send back a >>>> >>>>>http 202 to A and close the connection before forwarding >>>> >>>>the message on >>>> >>>>>to Node B. Now Node B gets the message and wants to send >>>> >>>>back an Ack >>>> >>>>>synchronously (due to the anonymous Ack). But it can't >>>> >>>>send the Ack >>>> >>>>>since the connection between Node A and the Intermediary is >>>> >>>>already closed. >>>> >>>>>Basically the problem is that the introduction of >> >>anonymous AcksTo >> >>>>>converts a oneway MEP into a two-way MEP. In order for it >>>> >>>>to work, all >>>> >>>>>intermediaries will need to be WSRM aware and keep >>>> >>>>connections open in >>>> >>>>>case synchronous acks need to be sent back. >>>>> >>>>>Proposal: >>>>> >>>>>* Specifically call out that the anonymous IRI is not >> >>to be used >> >>>>>in >>>>>AcksTo. >>>>>* AcksTo may take on the value of the "not allowed" IRI, >>>>> "_http://www.w3.org/@@@@/@@/addressing/none_";. When >>>> >>>>AcksTo takes on >>>> >>>>>this value, acknowledgement will only be sent back in >> >>response to >> >>>>>AckRequest messages. >>>>> >>>>>Lei >>>>> >>>>> >>>>> -----Original Message----- >>>>> *From:* Marc Goodner [mailto:mgoodner@microsoft.com] >>>>> *Sent:* Tuesday, August 23, 2005 3:16 PM >>>>> *To:* ws-rx@lists.oasis-open.org; Lei Jin; >> >>Christopher B Ferris >> >>>>> *Subject:* [ws-rx] Proposal for i012 >>>>> >>>>> I believe Chris Ferris had made a similar proposal >>>> >>>>earlier but in >>>> >>>>> the interest of a +1 and trying to move this along I'll >>>> >>>>make a more >>>> >>>>> formal proposal. >>>>> >>>>> >>>>> >>>>> Proposal: >>>>> >>>>> WS-RM was designed to be used with WS-Addressing in >> >>which the >> >>>>> behavior of the anonymous URI is defined as an address >>>> >>>>in an EPR. >>>> >>>>> There is no requirement that the anonymous URI must >> >>be used and >> >>>>> there are valid applications of it, therefore this >>>> >>>>issue should be >>>> >>>>> closed with no action >>>>> >>>> >>
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