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Re: [ws-rx] Anon / RM MakeConnection: [reply ep] = none

From: Paul Fremantle <paul@wso2.com>
Date: Wed, 09 Aug 2006 09:41:28 +0100
Message-ID: <44D99FB8.7050306@wso2.com>
To: Alastair Green <alastair.green@choreology.com>
CC: Christopher B Ferris <chrisfer@us.ibm.com>, public-ws-addressing@w3.org, public-ws-addressing-request@w3.org, ws-rx@lists.oasis-open.org

Alastair

I don't think there's anything wrong with [reply= none]. On the other
hand, I don't expect to have to put [reply=none] on every one-way
interaction I make. I don't believe there is anything wrong with the
current situation.

Paul

Alastair Green wrote:
> Chris, Paul:
>
> *What's wrong with [reply endpoint = none]?
>
> *1. None URI means "no response expected", implies transport ack only.
> Contents of transport response body would reasonably be ignored by a
> WS-A implementation.
>
> 2. WS-A receiver of [reply endpoint] = None URI will not stall for an
> application handoff or for application response: it will pass the
> inbound message, and immediately ack the sender, and lose all context
> (transport response, message id correlation information).
>
> 3. RM would be asking WS-A implementations to stop natural, generic
> behaviours 1. and 2., and become aware of RM.
>
> 4. None URI means ack only. Anon means SOAP envelope in the transport
> response, always. New URI needed to mean: "May be SOAP, may be ack".
> Receiver of new URI (APAO below) knows to stall for application
> release before acking (empty response body) or SOAPing (full response
> body).
> *
> **Alternatives
> *
> 1. We can't use [reply endpoint] = anon (the default) because the WS-A
> SOAP Binding limits this to cases where there is always a SOAP
> envelope in the transport response (ack only forbidden). I believe
> this is the /only/ obstacle. Everything else is proceeding from that
> WS-A limitation. (If this perceived limitation does not exist, then I
> would see no reason not to use anon URI.)
>
> 2. Create a special URI, as anticipated by the WS-A SOAP Binding, that
> means: "Transport response can either be message or ack-alone".
>
> 3. Call this special URI .../anonymous/permittingAckOnly (APAO). [Not
> a good name, a strawman]
>
> 4. Send MakeConnection/ReplyTo/Address=APAO. Allow ref-params in the
> normal manner. (Ref params can't be handled with current solution).
>
> 5. Permit MakeConnection to contain a sequence Identifier, if desired,
> (as per current solution).
>
> 6. Allow for an extension element in MC, if the app wants to identify
> the conversation. The identity of the conversation only has to be
> unambiguous between the application parties, so UUID is bound to be
> right, but not always needed. The type of the identification is an app
> issue. If you don't like that, permit MC to contain a connection
> identifier, type is UUID (closest to current solution).
>
> 7. Decide who's going to own the special APAO URI. It really should be
> WS-Addressing, as this is a general, app-level requirement. RM is
> permitting an /application /behaviour (the message stream is
> application content, which may, in the RM context, be bracketed by
> some RM set-up and tear-down, as it happens).
>
> 8. If process/timescales force RM to "stand in" for WS-Addressing,
> then this means worrying about impact on WS-A implementations (which
> is where this started from for me). See above re implications for WS-A
> implementations of use of none URI
>
> Alastair
>
>
>
>
>
>
>
>
>
>
> Christopher B Ferris wrote:
>>
>> Alastair,
>>
>> I don't think that MakeConnection "invites a response"... rather, it
>> opens up the back-channel
>> (when transmitted over a protocol such as HTTP that has an inherent
>> back-channel) for the
>> transmission of a message.
>>
>> I think that there is a difference... a large one at that.
>>
>> A SOAP Response is entirely different than a protocol response
>> message. In the context
>> of a oneway message, carried over a protocol such as HTTP, there is a
>> response message
>> that may not carry a SOAP envelope in its entity body. It is a
>> protocol-level response, not necessarily
>> a SOAP level-response. The fact that we are exploiting this is what
>> MakeConnection is all about.
>>
>> As Paul indicated, I would be happy if we suggested that WS-A none
>> URI be specified as the
>> ReplyTo address, but frankly, I think that that is something for the
>> WS-A WG to work out.
>>
>> Cheers,
>>
>> Christopher Ferris
>> STSM, Software Group Standards Strategy
>> email: chrisfer@us.ibm.com
>> blog: http://www.ibm.com/developerworks/blogs/dw_blog.jspa?blog=440
>> phone: +1 508 377 9295
>>
>> Alastair Green <alastair.green@choreology.com> wrote on 08/08/2006
>> 11:42:10 AM:
>>
>> > Chris,
>> >
>> > Redoing part of WS-A in RM creates difficulty in WS-A WSDL (start of
>> > thread). Raises question: Why won't standard WS-A anon facility work?
>> >
>> > You have to say something about where you reply to. If you want the
>> > reply to come on the back-channel then WS-A has a way of saying that
>> > (and you get that by default).
>> >
>> > If you say there is no reply, then you are saying: don't send a
>> > response. But MC precisely invites a response. How is a WS-A
>> > implementation supposed to understand (without being RM aware) that
>> > reply=none really means (functionally) reply=anon? I perceive
>> > unnecessary layering tangle. WS-A layer now expected to hold HTTP
>> > response for app, even though told that there is no response.
>> >
>> > Researching further, I don't understand why an RM-specific
>> > alternative to reply=anon has been introduced for the "address"
>> > case, but not for the "sequence" case.
>> >
>> > I believe regular "use back channel" feature of WS-A can be used,
>> > and the RM layer can handle RM "sessions", in both cases.
>> >
>> > Does my example of sequence case indicate expected behaviour? Would
>> > it be wrong to say MC/reply=anon with sequence case?
>> >
>> > First part of long message addresses Doug's points about the
>> > application-level set-up message: I don't understand the relevance
>> > of that type of message.
>> >
>> > Alastair
>> >
>> >
>> >
>> > Christopher B Ferris wrote:
>> >
>> > Alastair,
>> >
>> > Is this a long and drawn out manner of stating that when a message
>> > is a true oneway (e.g. no
>> > response is expected) then the wsa:ReplyTo should be the WS-A none
>> > URI rather than
>> > simply leaving it absent and hence falling trap to the "if not
>> > present, default to anon" gotcha?
>> >
>> > I guess I am not seeing an issue here, although I guess it would be
>> > fine if we recommended or required
>> > that the MakeConnection wsa:ReplyTo MAP carry the WS-A none URI.
>> >
>> > Cheers,
>> >
>> > Christopher Ferris
>> > STSM, Software Group Standards Strategy
>> > email: chrisfer@us.ibm.com
>> > blog: http://www.ibm.com/developerworks/blogs/dw_blog.jspa?blog=440
>> > phone: +1 508 377 9295
>> >
>> > public-ws-addressing-request@w3.org wrote on 08/08/2006 07:06:32 AM:
>> >
>> > > Doug, Paul --
>> > >
>> > > I'm going to try to address both your comments. if I can summarize
>> > > Paul's it was: what's the big deal about [reply endpoint] when
>> > > MakeConnection is "one-way"?.
>> > >
>> > > Given RX timescales you may want to treat these remarks as "early
>> > > public review".
>> > >
>> > > * * *
>> > >
>> > > Doug's message 1 is an application-level set-up call which
>> > > establishes common understanding of the UUID. This type of message
>> > > is exemplified by that shown in the CD example Step 1, unless I have
>> > > completely misunderstood.
>> > >
>> > > In that example, a subscriber, who cannot listen, sends a subscribe
>> > > message to a publisher, saying something like "subscribe me for
>> > > topics A, B, C. The identity of this subscription request is UUID
>> > > X". Thereafter, the publisher knows that X equals "subscription for
>> > > topics A, B, C".
>> > >
>> > > Assertion 1 (please correct me if I am wrong): The format, content
>> > > etc of this type of message (and its manner of transmission) are
>> > > entirely application-specific. It may or may not require an
>> > > acknowledgement. It could be sent by carrier pigeon, or by fax. The
>> > > subscribe message, if sent as SOAP-with-Addressing, might receive a
>> > > reply, or might not receive a reply, and if it did, it might receive
>> > > it anon or addressable. There are no RM rules that apply to this
>> > > message. There are only application rules. It cannot do its job
>> > > usefully unless it passes the UUID: that is all we can say.
>> > >
>> > > Assertion 2. At present there is an RM rule which says: "the
>> > > mutually understood UUID must be reflected in the [destination
>> > > endpoint] according to an RM URI scheme". There are no RM rules to
>> > > say whether the connection UUID, during the course of establishing
>> > > mutual understanding, travels alone, embedded in a URI, in a body
>> > > element or a header element. These are all matters of bilateral
>> > > agreement at an app level between (in this case) the
>> > > consumer/subscriber and the producer/publisher.
>> > >
>> > > [The example is potentially a bit misleading in this respect.
>> > >
>> > > The use of the full "anon-URI?id={uuid}" value in the <targetEPR/>,
>> > > and the use of the element name "targetEPR" make one think
>> > > "addressing", when one would be better off thinking "subscription
>> > > identity" (at an app level). The example set-up message would work
>> > > perfectly well if it read:
>> > >
>> > > <S:Body>
>> > >     <!-- subscription details -->  
>> > >     <SubscriptionIdentity>{uuid}</SubscriptionIdentity>
>> > > </S:Body>
>> > >
>> > > Btw, given that the use of MakeConnection requires a prior
>> > > understanding between two parties of the connection identity, there
>> > > seems no reason why {uuid} has to be a UUID. It does need to be
>> > > bilaterally unambiguous.]
>> > >
>> > > * * *
>> > >
>> > > Message 2 is MakeConnection. If the subscriber sends a
>> > > MakeConnection, specifying UUID X, then the publisher knows it is
>> > > dealing with traffic relating to subscription X, i.e. for topics A,
>> > > B and C. At an application level, we assume that the contract
>> > > thereafter is: start reliably communicating a stream of messages,
>> > > relating to topics A, B and C, therefore implying sequence creation
>> > > etc, until something causes the stream to close.
>> > >
>> > > So the subscriber will repeatedly send MakeConnection, citing the
>> > > UUID X, read the HTTP response, and handle the response as if it
>> > > were an inbound RM/RM-app message.
>> > >
>> > > The exchange that RM defines (rather than illustrates) is the
>> > > MakeConnection, back-call-on-the-connection one. It's this exchange
>> > > that I am discussing. MakeConnection is the message affected by the
>> > > WSAW anon=required discussion, as I see it.
>> > >
>> > > [While it is probably helpful for diagnostic reasons to repeat the
>> > > UUID back to the sender of MakeConnection in the [destination
>> > > endpoint], it is actually redundant, as the HTTP Response is
>> > > automatically and uniquely correlated with the HTTP Request. This
>> > > might lead one to the conclusion that the simple solution would have
>> > > been: send UUID on MakeConnection, and then respond to it on the
>> > > anonymous back-channel without reflection of UUID in any form
>> > > However, this would reduce the symmetry with the Sequence identified
>> > > use of MakeConnection, see comments later]
>> > >
>> > > * * *
>> > >
>> > > There are two modes in which this exchange can work (reflecting the
>> > > joint proposal, as I understand it):
>> > >
>> > > a) Send response as part of a sequence that already exists
>> > > b) Use response to create a new sequence, etc
>> > >
>> > > This is relevant to answering Paul F's question, relating to the
>> > > significance of ReplyTo.
>> > >
>> > > If there is a sequence, then the sequence Identifier is a
>> > > correlation synonym for the UUID. The reply message may be sent on
>> > > the back-channel; it must carry the wsrm:Identifier (as a separate
>> > > header element), it need not carry the UUID.
>> > >
>> > > If there is no sequence, then the reply message must carry or imply
>> > > the UUID. (I'm going to assume that carrying the UUID is better than
>> > > implying it.) The question is how?
>> > >
>> > > Looking at these two cases, it is striking that both
>> > >
>> > > a) require a response on the back-channel,
>> > > b) need to carry an identifier (one of the sequence, one of the
>> > > "connection"/"session")
>> > >
>> > > Doug's comment that there is no wsa:ReplyTo on the MakeConnection,
>> > > that it is "one way", is relevant here. In fact there is no such
>> > > thing (in the XML infoset) as a non-existent [reply endpoint]. If
>> > > wsa:ReplyTo is absent, then it is inferred to be the anon-URI. The
>> > > only way you can stop that inference is to set the [reply endpoint]
>> > > to none or to a "real address". I don't think you want to do either
>> > > of those things, in this context.
>> > >
>> > > With these points in mind, I think it is worth looking again at my
>> > > previous postings.
>> > >
>> > > The orthodox way of saying "respond on the back-channel" is setting
>> > > [reply endpoint] to anon. This can be done explicitly or by
>> > > inference from absence.
>> > >
>> > > I think there has to be a good reason to invent a new way of
>> > > expressing this semantic. Doing so has repercussions (see the
>> > > original starting point of this thread, re WSA W anon/required). The
>> > > (very valuable) use case of MakeConnection does not require an
>> > > alternate mechnanism for stating the back channel semantic.
>> > >
>> > > We can illustrate all of this by placing three examples side by side:
>> > >
>> > > * * *
>> > >
>> > > 1. Example using sequence Identifier: MakeConnection and reply
>> [asper CD 04]
>> > > 2. Example using hypothetical connection identifier: MakeConnection
>> > > and reply [as it could be, simplified]
>> > > 3. Example using current Address [as per CD 04]
>> > >
>> > > 1a. Example using sequence Identifier: MakeConnection
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:MessageID>
>> > >         <wsa:Action>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/MakeConnection
>> > > </wsa:Action>
>> > >         <wsa:To>http://example.org/subscriptionService</wsa:To>
>> > > <!-- absent wsa:ReplyTo is equivalent to:    
>> > >         <wsa:ReplyTo>
>> > >             <wsa:Address>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/anonymous
>> > > </wsa:Address>
>> > >         </wsa:ReplyTo>
>> > > -->
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <wsrm:MakeConnection>            
>> > >             <wsrm:Identifier>http://Business456.
>> > > com/SubscribeTopics/Sequence/7456-3278</wsrm:Identifier>
>> > >         </wsrm:MakeConnection>
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > 1b. Example using sequence Identifier: reply to MakeConnection
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/71e0654e-5ce8-477b-bb9d-34f05cfcbc9e</wsa:MessageID>
>> > >         <wsa:RelatesTo>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:RelatesTo>
>> > >        
>> <wsa:ReplyTo><wsa:Address>http://example.org/subscriptionService
>> > > </wsa:Address></wsa:ReplyTo>
>> > >         <wsa:Action>http://example.com/subscriptionService/publish
>> > > </wsa:Action>
>> > >         <wsrm:Sequence>
>> > >             <wsrm:Identifier>http://Business456.
>> > > com/SubscribeTopics/Sequence/7456-3278</wsrm:Identifier>
>> > >             <wsrm:MessageNumber>1</wsrm:MessageNumber>
>> > >         </wsrm:Sequence>
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <!-- Publication re A, B or C -->
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > 2a. Example using hypothetical connection identifier: MakeConnection
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:MessageID>
>> > >         <wsa:Action>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/MakeConnection
>> > > </wsa:Action>
>> > >         <wsa:To>http://example.org/subscriptionService</wsa:To>
>> > > <!-- absent wsa:ReplyTo is equivalent to:    
>> > >         <wsa:ReplyTo>
>> > >             <wsa:Address>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/anonymous
>> > > </wsa:Address>
>> > >         </wsa:ReplyTo>
>> > > -->
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <wsrm:MakeConnection>            
>> > >             <wsrm:ConnectionIdentifier>http://Business456.com/
>> > > SubscribeTopics/Stream/7457</wsrm:ConnectionIdentifier>
>> > >         </wsrm:MakeConnection>
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > 2b. Example using hypothetical connection identifier: reply to
>> > > MakeConnection (CreateSequence)
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/71e0654e-5ce8-477b-bb9d-34f05cfcbc9e</wsa:MessageID>
>> > >         <wsa:RelatesTo>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:RelatesTo>
>> > >         <wsa:Action>http://docs.oasis-open-
>> > org/wsrx/wsrm/200608/CreateSequence
>> > > </wsa:Action>
>> > >        
>> <wsa:ReplyTo>http://example.org/subscriptionService</wsa:ReplyTo>
>> > >         <wsrm:ConnectionIdentifier>
>> > >             http://Business456.com/SubscribeTopics/Stream/7457
>> > >         </wsrm:ConnectionIdentifier>          
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <wsrm:CreateSequence>
>> > >             <wsrm:AcksTo>
>> > >                 <wsa:Address>http://example.org/subscriptionService
>> > > </wsa:Address>
>> > >             </wsrm:AcksTo>
>> > >         </wsrm:CreateSequence>
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > 3a. Example using wsrm:Address: MakeConnection
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:MessageID>
>> > >         <wsa:Action>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/MakeConnection
>> > > </wsa:Action>
>> > >         <wsa:To>http://example.org/subscriptionService</wsa:To>
>> > > <!-- absent wsa:ReplyTo is equivalent to:    
>> > >         <wsa:ReplyTo>
>> > >             <wsa:Address>http://docs.oasis-open.
>> > org/wsrx/wsrm/200608/anonymous
>> > > </wsa:Address>
>> > >         </wsa:ReplyTo>
>> > > -->
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <wsrm:MakeConnection>            
>> > >             <wsrm:Address>
>> > >                 http://docs.oasis-open.
>> > >
>> org/wsrx/wsrm/200608/anonymous?id=550e8400-e29b-11d4-a716-446655440000
>> > >             </wsrm:Address>
>> > >         </wsrm:MakeConnection>
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > 3b. Example using wsrm:Address: reply to MakeConnection
>> (CreateSequence)
>> > >
>> > > <S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
>> > >             xmlns:wsrm="http://docs.oasis-open.org/ws-rx/wsrm/200608"
>> > >             xmlns:wsa="http://www.w3.org/2005/08/addressing">
>> > >     <S:Header>
>> > >         <wsa:MessageID>http://example.org/subscriptionService/
>> > > guid/71e0654e-5ce8-477b-bb9d-34f05cfcbc9e</wsa:MessageID>
>> > >         <wsa:RelatesTo>http://example.org/subscriptionService/
>> > > guid/61e0654e-5ce8-477b-bb9d-34f05cdcbc9e</wsa:RelatesTo>
>> > >         <wsa:Action>http://docs.oasis-open-
>> > org/wsrx/wsrm/200608/CreateSequence
>> > > </wsa:Action>
>> > >         <wsa:To>
>> > >
>> > > <!-- I believe this is WS-A illegal: reply To must equal request
>> > > ReplyTo/Address. -->          
>> > >
>> > >             http://docs.oasis-open.org/wsrx/wsrm/200608/anonymous?
>> > > id=550e8400-e29b-11d4-a716-446655440000
>> > >         </wsa:To>
>> > >        
>> <wsa:ReplyTo>http://example.org/subscriptionService</wsa:ReplyTo>
>> > >     </S:Header>
>> > >     <S:Body>
>> > >         <wsrm:CreateSequence>
>> > >             <wsrm:AcksTo>
>> > >                 <wsa:Address>http://example.org/subscriptionService
>> > > </wsa:Address>
>> > >             </wsrm:AcksTo>
>> > >         </wsrm:CreateSequence>
>> > >     </S:Body>
>> > > </S:Envelope>
>> > >
>> > > Yours,
>> > >
>> > > Alastair
>> > >
>> > > Doug Davis wrote:
>> > >
>> > > Alastair,
>> > >   I think you're mixing up the messages a bit.  There are two
>> messages
>> > > at play:
>> > > 1 - the message containing the EPR to send subsequent messages to.  
>> > >     In some cases this message will have the EPR in its wsa:ReplyTo
>> > >     header, but it could also be placed someplace else depending
>> > >     on its use.  And it is this EPR that needs to be tagged as the
>> > >     polling one (ie. it has the RM anon URI).
>> > >     This message will contain application specific data in the Body
>> > >     so your suggestion of placing some UUID in there will not work.
>> > >     This gets back to the necessity to keep all info about where to
>> > >     send messages encapsulated into whatever EPR we want to be
>> tagged
>> > >     as the polling one.
>> > >
>> > > 2 - the MakeConnection message.
>> > >     This message does not have a wsa:ReplyTo, its a one-way.  This
>> > >     message does contain a Body which is the correlation info used
>> > >     by the receiver of this message to find an appropriate message
>> > >     to send back.  So, basically the stuff in the Body must match
>> > >     the EPR from message 1.  And given that in some cases the only
>> > >     thing remaining from the EPR in message 1 is the serialized
>> > >     version of it, we must be able to find messages based solely
>> > >     on what's in the outgoing message itself.  Which means the
>> > >     wsa:To field.  Again, ref-p's are bad for this purpose. :-)
>> > >
>> > > HTH
>> > >
>> > > thanks
>> > > -Doug
>> > >
>> > >
>> > >
>> > > Alastair Green <alastair.green@choreology.com> wrote on 08/07/2006
>> > > 02:02:55 PM:
>> > >
>> > > > Doug,
>> > > >
>> > > > I think I'm connecting, if you'll pardon the pun.
>> > > >
>> > > > 1. As I read WS-A, the [destination endpoint][address] must be set
>> > > > to [reply endpoint][address] for a reply.
>> > > >
>> > > > 2. If [reply endpoint] is omitted (as per the CD example), then
>> > > > [reply endpoint] = anon, by default.
>> > > >
>> > > > 3. If [destination endpoint] = "anon-URI?id={uuid}", then
>> > > > [destination endpoint] <> [reply endpoint][address] (which was
>> > > > simple, unornamented anon-URI), which contradicts premise 1.
>> > > >
>> > > > Does that make sense? If so, then I think you would need to set
>> > > > [reply endpoint] to none, explicitly, to avoid that clash (given
>> > > > RM's current approach). But this causes
>> > > >
>> > > > 4. The WS-A processor that sent MakeConnection to get very
>> confused.
>> > > > It wasn't expecting anything but an HTTP 200 series by way of a
>> > > > response, but is about to get a full-scale SOAP message
>> bounding back.
>> > > >
>> > > > +++
>> > > >
>> > > > Further thoughts, which continue, in my mind, to question the
>> > > > current RM approach, but which may ease the WSA W problem.
>> > > >
>> > > > a) You could have defined an extension element in the [reply
>> > > > endpoint] for the UUID.
>> > > >
>> > > > b) Or, you could have chosen to send the UUID in the body element.
>> > > >
>> > > > c) In either case, this could team up with setting [reply
>> > > endpoint] to anon.
>> > > >
>> > > > d) As in 3. above, you shouldn't then set response [destination
>> > > > endpoint] to anon?id={uuid}.
>> > > >
>> > > > e) So, you need to set [reply endpoint] to anon, and set
>> > > > [destination endpoint][address] to anon.
>> > > >
>> > > > f) which begs the question, where does the UUID go?
>> > > >
>> > > > g)  If you passed an extension element UUID, or a UUID in the body
>> > > > element, and then passed it back as an extension element in the
>> anon
>> > > > EPR that should be OK, because you have followed the rules for
>> reply
>> > > > formulation with respect to the [destination endpoint][address]
>> > > > /[reference parameters]. The fact you have chosen to put an
>> > > > extension element in the response is WS-A 3.3/3.4 legal, as I read
>> > > > it. That's a higher-layer behaviour that does not contradict WS-A
>> > > > base behaviour, which is constrained.
>> > > >
>> > > > +++
>> > > >
>> > > > Why is g) not viable in your view? The processors that need to
>> > > > understand the body/extension UUID element are the RM senders and
>> > > > responders (not the WS-A processors, which passively pass on the
>> > > > UUID to the RM receiver of MakeConnection, and pass on the
>> extension
>> > > > element to the RM receiver of the response).
>> > > >
>> > > > In other words, the awareness of RM-ness that is demanded in
>> > > > formulating MakeConnection, and in replying to it, resides in the
>> > > > same place, and at the same level, as in the current (CD) solution.
>> > > >
>> > > > The difference being: that the MakeConnection is now a regular
>> > > > [reply endpoint] = anon. At which point special WSAW rules are
>> not needed.
>> > > >
>> > > > I don't see any lesser or greater problem with intermediaries,
>> > > > onward transmission etc than would apply with the current
>> solution,
>> > > > if that is a concern. On this point, I think I may be missing
>> > > > something, or misunderstanding your area of concern?
>> > > >
>> > > > So, to summarize:
>> > > >
>> > > > 1. asimple-non out, special, ornamented-anon back is a problem.
>> > > > 2. none out, anon back is a problem.
>> > > > 3. extension element UUID out, extension element UUID back, is no
>> > > > different, in layer terms, than body UUID out, ornamented address
>> > > > back, i.e. is not a problem.
>> > > > 4. anon out means no problem with anon = required.
>> > > >
>> > > >
>> > > > * * *
>> > > >
>> > > > My last point was indeed completely beside the point of your
>> issue :
>> > > > -) -- it is an independent issue about WSAW, and a limitation that
>> > > > the proposed syntax seems to impose by applying the flag across
>> all
>> > > > "response endpoints".
>> > > >
>> > > > Alastair
>> > > >
>> > > > Doug Davis wrote:
>> > > >
>> > > > Alastair,
>> > > >   We did consider adding some extra metadata to the EPR
>> (outside of
>> > > > the wsa:Address and ref-p's), but there's a problem - this
>> metadata
>> > > > is not copied over into the response message - just the
>> wsa:Address
>> > > > and ref-p's are.  This means that any data placed elsewhere in the
>> > > > EPR is lost once the message is serialized.  So unless we
>> assume the
>> > > > impl can hold on to the original EPR for the entire message path
>> > > > (which we can't in distributed systems), the identity part must be
>> > > > in either the address or ref-p's.  And, as you said, ref-p's
>> aren't
>> > > > good for this.
>> > > >
>> > > >   What's interesting about your anon?unique-id example is that
>> that
>> > > > solution might work very nicely (we talked about this in the
>> past) -
>> > > > but as you said it would require WSA to say anon URIs 'start
>> > > > with...' - and WSA is closed :-(
>> > > >
>> > > >   I got a bit lost on your last point - it almost sounded like a
>> > > > complaint about the current WSA WSDL spec instead of my issue -
>>  or
>> > > > did I not follow it?
>> > > >
>> > > >   I noticed that on the agenda for tomorrow's WSA call (I think
>> its
>> > > > tomorrow) is a CR issue that mentioned how this wording in the
>> WSDL
>> > > > spec prevents the use of "none".  I can't help but think that both
>> > > > issues (mine and the other CR issue) would be solved nicely if the
>> > > > wording were turned around a bit and said something about how this
>> > > > flag indicates whether or not the endpoint supports addressable
>> > > > endpoints in the response EPRs.  Not sure of the exact wording,
>> but
>> > > > if instead of taking about specific URIs (like anon and none) it
>> > > > talked about whether the endpoint supported the notion of creating
>> > > > it own connections to the EPR then it wouldn't need to get into
>> the
>> > > > business of listing all of the URIs that are valid.  And I
>> think it
>> > > > would relay the exact same information.
>> > > >
>> > > > thanks
>> > > > -Doug
>> > > >
>> > > >
>> > >
>> > > >
>> > > > Alastair Green <alastair.green@choreology.com>
>> > > > 08/04/2006 10:57 AM
>> > > >
>> > > > To
>> > > >
>> > > > Doug Davis/Raleigh/IBM@IBMUS
>> > > >
>> > > > cc
>> > > >
>> > > > public-ws-addressing@w3.org, public-ws-addressing-request@w3.org,
>> > > > ws-rx@lists.oasis-open.org, abbieb@nortel.com, aclark@novell.com,
>> > > > akira.tanaka.pr@hitachi.com, aleyfer@actional.com,
>> anash@reactivity.com,
>> > > > andreas.bjarlestam@ericsson.com, anil.edakkunni@soa.com, anil.
>> > > john@jhuapl.edu
>> > > > , Anish.Karmarkar@oracle.com, Anthony Nadalin/Austin/IBM@IBMUS,
>> > > > asakala@iona.com, ash@rainingdata.com, ashok.malhotra@oracle.com,
>> > > > asirveda@microsoft.com, atarashi@sv.nec-labs.com,
>> atmanes@gmail.com,
>> > > > audet@nortel.com, barreto@adobe.com, bhakti.mehta@sun.com, blake.
>> > > > dournaee@intel.com, bob.freund@hitachisoftware.com,
>> bob.sunday@pwgsc.gc.ca
>> > ,
>> > > > b.eckenfels@seeburger.de, carolina.canales@ericsson.com,
>> > chamikara@wso2.com
>> > > ,
>> > > > chappell@sonicsoftware.com, Charles Levay/Raleigh/IBM@IBMUS,
>> > > > chouthri@sv.nec-labs.com, Christopher B Ferris/Waltham/IBM@IBMUS,
>> > > > Christopher.Kurt@microsoft.com, chris.hipson@bt.com, "'von
>> > Riegen, Claus'"
>> > > > <claus.von.riegen@sap.com>, coevans@microsoft.com,
>> > cunningham_david@bah.com
>> > > ,
>> > > > dan@actional.com, "'Burdett, David'" <david.burdett@sap.com>,
>> > > > dconnelly@openapplications.org, Diane Jordan/Raleigh/IBM@IBMUS,
>> > > > dkmin@konkuk.ac.kr, dleshc@tibco.com, dmoberg@us.axway.com,
>> > > dnickull@adobe.com
>> > > > , "'David Orchard'" <dorchard@bea.com>, doug.bunting@sun.com,
>> > > > eisaku.nishiyama.dd@hitachi.com, email@cbvenkat.net,
>> eoghan.glynn@iona.com
>> > ,
>> > > > Eric.Newcomer@iona.com, eric.rajkovic@oracle.com, eric.
>> > > > wells@hitachisoftware.com, ganga.sah@oracle.com,
>> gatfora@uk.ibm.com,
>> > > > gboschi@sonicsoftware.com, gdaniels@sonicsoftware.com,
>> "'Gilbert Pilz'"
>> > > > <Gilbert.Pilz@bea.com>, girish.juneja@intel.com,
>> gregcarp@microsoft.com,
>> > > > greg.pavlik@oracle.com, hbenmalek@us.fujitsu.com,
>> heiko.braun@jboss.com,
>> > > > ian.c.jones@bt.com, ian_robinson@uk.ibm.com,
>> james.speer@capgemini.com,
>> > > > jamie.clark@oasis-open.org, jdurand@us.fujitsu.com, jeff.
>> > > > mischkinsky@oracle.com, jekanaya@cs.indiana.edu,
>> Jiri.Tejkl@systinet.com,
>> > > > jjchoe@tmax.co.kr, jkchoi@methodi.com, jmarsh@microsoft.com, joeri.
>> > > > van_cleynenbreugel@alcatel.be, john.gotze@oasis-open.org, john.
>> > > kemp@nokia.com
>> > > > , joseph.2.waller@bt.com, junghc@nca.or.kr, jypyon@nca.or.kr, k-
>> > > > seki@da.jp.nec.com, kcyee@cecid.hku.hk, kiwasa@jp.fujitsu.com,
>> > > > lburch@novell.com, lily.liu@webmethods.com, "'Lei Jin'"
>> <ljin@bea.com>,
>> > > > machi@nca.or.kr, "'Mark Little'" <mark.little@jboss.com>,
>> > > > "'Schenecker, Mark'" <mark.schenecker@sap.com>, "'de Boer,
>> Martijn'"
>> > > > <martijn.de.boer@sap.com>, "'Raepple, Martin'"
>> <martin.raepple@sap.com>,
>> > > > mary.mcrae@oasis-open.org, matsuki.yoshino.pw@hitachi.com,
>> > > mckierna@uk.ibm.com
>> > > > , mgoodner@microsoft.com, mhb@itst.dk, "'Bechauf, Michael'"
>> > > > <michael.bechauf@sap.com>, mike.grogan@sun.com,
>> millwood@uk.ibm.com,
>> > > > mlovett@uk.ibm.com, mlyons@layer7tech.com, mschenecker@e2open.com,
>> > > > mwang@tibco.com, nickr@enosis.com, nilo.mitra@ericsson.com,
>> > > > nobuyuki.yamamoto.vw@hitachi.com, Ondrej.Hrebicek@microsoft.com,
>> > > paul@wso2.com
>> > > > , pauld@mitre.org, paul.cotton@microsoft.com,
>> paul.knight@nortel.com,
>> > > > peter.furniss@erebor.co.uk, peter_niblett@uk.ibm.com,
>> pete.wenzel@sun.com
>> > ,
>> > > > prateek.mishra@oracle.com, pyendluri@webmethods.com, Richard
>> > > > Salz/Cambridge/IBM@IBMUS, robin@oasis-open.org,
>> sada@jp.fujitsu.com,
>> > > > "'Patil, Sanjay'" <sanjay.patil@sap.com>, sanka@wso2.com,
>> > scayron@acord.org
>> > > > , Scott Hinkelman/Austin/IBM@IBMUS, shengsong.ni@oracle.com,
>> > > > shivajee@tibco.com, srcarter@novell.com, stefanba@microsoft.com,
>> > > > "'Rossmanith, Stefan'" <stefan.rossmanith@sap.com>, "'Winkler,
>> Steve'"
>> > > > <steve.winkler@sap.com>, sumit.gupta@oracle.com,
>> tboubez@layer7tech.com,
>> > > > tejeswar.das@iona.com, thomas.erl@soasystems.com,
>> thomas.t.bui@boeing.com
>> > ,
>> > > > timothy@drummondgroup.com, toby.considine@unc.edu,
>> tom@coastin.com,
>> > > > "'Yalcinalp, Umit'" <umit.yalcinalp@sap.com>,
>> vfurman@webmethods.com
>> > > > , "'Shipkowitz, Vicki'" <vicki.shipkowitz@sap.com>,
>> vikas@sonoasystems.com
>> > > > , "'Videlov, Vladimir'" <vladimir.videlov@sap.com>, Martin Chapman
>> > > > <martin.chapman@oracle.com>
>> > > >
>> > > > Subject
>> > > >
>> > > > Re: Comment on WSDL spec: use of Anonymous Element
>> > > >
>> > > >
>> > > >
>> > > >
>> > > > Hi Doug,
>> > > >
>> > > > Comments interspersed:
>> > > >
>> > > > Doug Davis wrote:
>> > > >
>> > > > Alastair,
>> > > >  There are a couple of different things at play here. First, sorry
>> > > > about the long cc-list but the wsrx mailing list still doesn't
>> > > > appear to work so I need to include the entire wsrx team
>> manually :-(
>> > > > I thought my mail client was going to expire when I just did
>> "reply all".
>> > > >
>> > > > In a non-anonymous world the wsa:Address field represents both the
>> > > > fact that the destination can access connections and it identifies
>> > > > the party.  And I think that makes sense.  There is no reason
>> to not
>> > > > have a single URI do that (let's not get into the 'identity' issue
>> > > > w.r.t. ref-p's  :-).   So, if we then switch over to the anonymous
>> > > > case, IMO, I don't believe the implementation should need to
>> change
>> > > > w.r.t. the purpose of this URI.
>> > > > Here's what I don't understand. In the non-anon case an EPR
>> (address
>> > > > + stuff) is used to target. In the anon case, so far as I can
>> tell,
>> > > > there is nothing in WS-A to stop the same "full EPR" (address +
>> > > > stuff) be 

-- 

Paul Fremantle
VP/Technology, WSO2 and OASIS WS-RX TC Co-chair

http://feeds.feedburner.com/bloglines/pzf
paul@wso2.com

"Oxygenating the Web Service Platform", www.wso2.com
Received on Wednesday, 9 August 2006 08:41:56 GMT

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