OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

sca-bindings message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: RE: [sca-bindings] ISSUE 2 - Callback support over the Web Service binding


Hi Eric,

Discussion whether the issue should be accepted is exactly what I wanted
to achieve (sorry if I failed to communicate it clearly).

I wanted to clarify whether the advanced callback semantics described in
the Java API& annotations is something important and vital for the SCA.
Hence the ws.binding and more importantly each new binding in scope
(jca, etc.) should accept an issue and adjust its spec to show how it
can be supported.

Or there are some issues with the callbacks, and in that case the issue
should not be opened here, but raised somewhere else. For example one
solution is to have a new policy intent - @dynamicCallback, so that each
vendor when supplying a binding may choose to say - "no support for such
SCA reply-to-s that are different than the reply-to-s in the underlying
protocol".

I have raised this in the assembly TC as per your request.


Best Regards
Peter



-----Original Message-----
From: Eric Johnson [mailto:eric@tibco.com] 
Sent: Wednesday, 3. October 2007 18:55
To: sca-bindings@lists.oasis-open.org
Subject: Re: [sca-bindings] ISSUE 2 - Callback support over the Web
Service binding

Hi,

Two thoughts here:

As per our proposed (but not yet adopted) issues process, issues are not
supposed to be discussed until accepted - except insofar as the
discussion is towards whether they should be accepted.

Second, it looks to me like the email below is digging into a separate
issue. And I cannot quite figure out whether it is coupled to ISSUE #2,
or genuinely separate. If separate, as issues ed., I'd love to see a
separate issue filed....

-Eric.

Peshev, Peter wrote:
> Hi
>
> When speaking about redirecting the callback, by API it is possible to
> redirect it to another component, whose services could be lacking
> binding.ws and instead having only some other binding /*let's say
> binding.jms due to the current lack of other bindings in the OASIS TC
:)
> */. 
>
> If that should be a supported scenario (outbound one binding, inbound
> another) that looks that the callbackId-s should be something SCA
> specific, and hardly rely on some WS-standard. I am little bit
confused
> in which TC (java, assembly, bindings) that should be addressed.
>
> Any thoughts / comments? 
>
> Btw, I personally dislike refirecting the callback since that is
> actually dynamic appearance of wires (invocation paths) via java code
> usage. 
>
> That introduces hidden dependencies among components, which cannot be
> analyzed and displayed by any tooling (except some heuristic code
> parsing), cannot be overridden by the assembler via SCDL files and
> somewhat hinders the main focus of component reuse and SOA. In
addition
> such dynamic redirecting is likely to complicate any implementation
> which spans beyond one JVM.
>
>
> Best Regards
> Peter
>
>
> -----Original Message-----
> From: Simon Nash [mailto:NASH@uk.ibm.com] 
> Sent: Tuesday, 2. October 2007 13:51
> To: sca-bindings@lists.oasis-open.org
> Subject: Re: [sca-bindings] ISSUE 2 - Callback support over the Web
> Service binding
>
> Using the wsa:ReplyTo header for the callback endpoint does not seem
to 
> exactly match SCA callback semantics, which allow callback messages to
> be 
> directed to a different endpoint from the endpoint that receives the
> reply 
> to the original request (by calling setCallbackObject() with a 
> ServiceReference).  Using wsa:ReplyTo also requires a message ID to be

> added to the original request and the same message ID to be returned
on 
> the reply and any callbacks in the wsa:RelatesTo header.  This is more
> of 
> an observation than a problem, though it does require extra state to
be 
> maintained for the message IDs being exchanged.
>
> In Tuscany, we did not use wsa:Reply To.  Instead we used the 
> WS-Addressing wsa:To endpoint reference with reference parameters to 
> represent the callback endpoint (as a wsa:EndpointReference), the
> callback 
> ID, and the conversation ID for stateful callbacks.
>
> I did not propose a specific solution when opening this issue because
I 
> wanted to open this up to as many suggestions and options as possible.
> The 
> discussion around wsa:ReplyTo has been interesting.  Perhaps someone
> will 
> have an idea on we can overcome the semantic mismatch that I mentioned

> above.  I agree that defining a new header for SCA callbacks would be 
> undesirable.  Even the use of SCA-specific reference parameters seems
> less 
> than ideal, but without them I'm not sure how additional information
> like 
> the callback ID could be transmitted.  We can't use wsa:MessageID for 
> this, because of the statement in the WS-Addressing spec that "No two 
> messages with a distinct application intent may share a [message id] 
> property."  Perhaps the callback ID could be mapped into a
wsa:MessageID
>
> by adding a unique discriminator, so different callback requests could
> use 
> distinct message IDs from which the same callback ID could be
extracted.
>
>     Simon
>
> Simon C. Nash, IBM Distinguished Engineer
> Member of the IBM Academy of Technology
> Tel. +44-1962-815156  Fax +44-1962-818999
>
>
>
> Khanderao Kand <khanderao.kand@oracle.com> 
> 01/10/2007 22:47
>
> To
> Michael Rowley <mrowley@bea.com>
> cc
> sca-bindings@lists.oasis-open.org
> Subject
> Re: [sca-bindings] ISSUE 2 - Callback support over the Web Service
> binding
>
>
>
>
>
>
> Michael Rowley wrote:
>   
>> One problem with using WS-Addressing wsa:ReplyTo is that it is
usually
>> used to send the response message of a request/response pair.  I
don't
>> think that WS-Address forbids its use for subsequent messages
>> (callbacks), but it would at least be unconventional.
>>
>>     
> [khanderao] IMHO WS-Addressing does not make any assumptions on the 
> number of returned messages. It is upto the integration scenario to
have
>
> one or many.
>   
>> However, if we can't use wsa:ReplyTo, that would seem to imply that
we
>> have to devise our own header to use, but that would be getting
>> dangerously close to inventing a wire-level protocol, which we don't
>> want to be doing.
>>
>>     
> [khanderao] Introducing SCA specific correlation / replyTo parameters 
> would not be essential. As far as possible we should be using the 
> available standards,  like WSA / WS-Coordination etc..
>   
>> Michael
>>
>> -----Original Message-----
>> From: Eric Johnson [mailto:eric@tibco.com] 
>> Sent: Monday, October 01, 2007 12:16 PM
>> To: sca-bindings@lists.oasis-open.org
>> Subject: Re: [sca-bindings] NEW ISSUE: Callback support over the Web
>> Service binding
>>
>> Created as: http://www.osoa.org/jira/browse/BINDINGS-2
>>
>> -Eric.
>>
>> Simon Nash wrote:
>>
>>     
>>> TARGET:
>>>
>>> Web Service Binding specification, section TBD
>>>
>>> DESCRIPTION:
>>>
>>> The Web Service binding provides no example or suggestion for how
SCA
>>>       
>
>   
>>> callback semantics could be carried over Web services.  There is an 
>>> example in section 2.2.3 for how conversation semantics could be 
>>> supported.  It would be good to give some guidance (somewhere in the
>>>
>>>       
>> range 
>>
>>     
>>> between example and normative) for what could be done for callbacks.
>>>
>>>       
>> One 
>>
>>     
>>> possibility is to make use of the capabilities provided by
>>>
>>>       
>> WS-Addressing.
>>
>>     
>>> PROPOSAL:
>>>
>>> None yet.
>>>
>>>
>>>
>>>
>>>
>>>
>>> Unless stated otherwise above:
>>> IBM United Kingdom Limited - Registered in England and Wales with
>>>
>>>       
>> number 
>>
>>     
>>> 741598. 
>>> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire
>>>       
> PO6
>   
>> 3AU
>>
>>     
>>>
>>>
>>>
>>>
>>>       
>
>
>
>
>
>
>
>
> Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with
number
>
> 741598. 
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
> 3AU
>
>
>
>
>
>
>   


[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]