Re: [ws-tx] Issue 007 - WS-C: Make Register/RegisterResponse retriable

[Mark Little <mark.little@jboss.com>]

Ian Robinson wrote:

>
>
>Regarding WS-RM, the "scope of work" section of the charter states:
>
>"As general principles, these protocols ... must not depend on the
>availability of reliable message delivery mechanisms outside of these
>specifications."
>  
>
+1

>
>
>This issue proposes a change to the semantic of the Register request but I
>believe that none is needed. Retrying a Register request because of network
>failures is not the only scenario in which a Participant can be registered
>multiple times for the same transaction. The important consideration is
>whether or not the multiple participant instances will behave properly when
>they are directed to complete according to the specific agreement protocol
>(e.g. AT or BA). And the state tables ensure that they can.
>
>
>
>If the TC believes clarification is required then I would suggest the
>following text:
>
>A Coordinator is not required to detect duplicate Register messages, but
>MAY attempt to do so by means that are out of the scope of this
>specifiction. A registration requester MAY send multiple Register messages
>to a Coordinator that does not detect duplicates - for example because it
>retried a Register request following a lost RegisterResponse. If a
>registration requester registers multiple times for the same activity then
>the registered Participants MUST be prepared to handle multiple protocol
>messages from a Coordinator that treats the multiple Register requests as
>distinct Participants. There are a number of simple strategies for
>accomplishing this. For example, the registration requester can generate a
>unique ReferenceParameter for each Participant EPR that is passed in a
>Register request.
>  
>
I would agree with this under the following assumption (or maybe 
clarifications are needed): I assume you're implicitly talking about 
removing the fault on multiple participant registrations?

Mark.

>
>Regards,
>Ian Robinson
>STSM, WebSphere Messaging and Transactions Architect
>IBM Hursley Lab, UK
>ian_robinson@uk.ibm.com
>
>
>                                                                           
>             Alastair Green                                                
>             <alastair.green@c                                             
>             horeology.com>                                             To 
>                                       Doug Davis <dug@us.ibm.com>         
>             13/12/2005 17:19                                           cc 
>                                       ws-tx@lists.oasis-open.org          
>                                                                   Subject 
>                                       Re: [ws-tx] Issue 007 - WS-C: Make  
>                                       Register/RegisterResponse retriable 
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>
>
>
>+1.
>
>Either we do it at the coord protocol level, or we start to mandate
>something like WS-RM, which I would not favour, and would create some
>pretty major ripple effects in specs and implementations.
>
>Alastair
>
>Doug Davis wrote:
>
>      And what is that transport mechanism?  By default neither WSA nor
>      SOAP will do
>      retries.
>      -Doug
>
>
>                                                                           
> Kevin Conner                                                              
> <Kevin.Conner@jboss.co                                                    
> m>                                                                        
>                                                                        To 
>                                     Doug Davis/Raleigh/IBM@IBMUS          
> 12/13/2005 04:31 AM                                                    cc 
>                                     Christopher B                         
>                                     Ferris/Waltham/IBM@IBMUS, Mark Little 
>                                     <mark.little@arjuna.com>,             
>                                     ws-tx@lists.oasis-open.org            
>                                                                   Subject 
>                                     Re: [ws-tx] Issue 007 - WS-C: Make    
>                                     Register/RegisterResponse retriable   
>                                                                           
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>
>
>      Doug Davis wrote:
>      > One thing that concerns me about using the wsa:MessagID is the
>      assumption
>      > that you'll use the same messageID on each retry.  Can the Tx spec
>      really
>      > require this?  Other specs (like WSA) which are infrastructural can
>
>      > probably make
>      > this kind of requirement (if they need to), but I always viewed Tx
>      as
>      > sitting on top
>      > of these infrastructural layers and not so much as being part of
>      them.
>      > Implementations
>      > will vary on this view but I wouldn't think Tx would want to
>      mandate this
>      > kind of choice.
>      > thanks,
>      > -Doug
>
>      This really came out of the description of the original problem.  A
>      request/response conversations was initiated and the initiator
>      crashed
>      before receiving the response.  The replay of a message at this
>      level,
>      especially as we are using WS-Addressing, would surely become the
>      domain
>      of a reliable transport.  My suggestion was therefore to defer this
>      to
>      the transport mechanism to replay the conversations and not the
>      higher
>      level protocols.
>
>                      Kev
>
>
>  
>