Re: [ws-rx] MessagePending

[Paul Fremantle <paul@wso2.com>]

Doug

This would be kind of cool, but I'm slightly concerned what impact it 
might have on various implementations. The MakeConnection call primes 
the RMD to "expect" a pending message on the response. But I'm not 
convinced it isn't doable. I'd like to get my implementation team's input.

Paul

Doug Davis wrote:
>
> Anish,
>   I don't think I was clear.  My pondering wasn't about the 
> MakeConnection message but rather about some other message - like some 
> application message.  If the client just happens to be sending a 
> one-way to the server and there's no response (its a one-way) then I 
> was wondering if the server could use the wsa:From/wsa:Address value 
> (if its set to RManonURI) to look for messages to send on that empty 
> back-channel.  Thus saving the overhead of the client having to send 
> another MakeConnection.
> thanks
> -Doug
>
>
>
> *Anish Karmarkar <Anish.Karmarkar@oracle.com>*
>
> 10/06/2006 01:51 PM
>
> 	
> To
> 	Doug Davis/Raleigh/IBM@IBMUS
> cc
> 	ws-rx@lists.oasis-open.org
> Subject
> 	Re: [ws-rx] MessagePending
>
>
>
> 	
>
>
>
>
>
> Doug Davis wrote:
> >
> > Would we always be able to know it though?  When the MessagePending
> > header flows as a result of the MakeConnection there's a "query
> > expression" associated with the MakeConnection.  In cases where the
> > message on the transport request flow was not a MakeConnection then I'm
> > not sure what value the server would use to determine if there are
> > messages pending - i.e. what "query expression" would it use to do the
> > check?  Interestingly enough, I have been recently wondering if we 
> could
> > use the wsa:From header for this purpose.  If a one-way message was on
> > the transport request flow, and since its a one-way there was no
> > response, could the server look at the wsa:From, and if it used the RM
> > anon URI, use that as an optimized MakeConnection?
>
> Can you elaborate on this?
>
> What/which information in the pending messages can the server use to
> figure out which message to send, if the sender identifying information
> is in the wsa:From of MakeConnection?
> If only wsa:To was an EPR (sigh).
>
> -Anish
> --
>
> >  In other words, does
> > wsa:From identify the sender?  WSA would seems to say 'yes'.  This 
> could
> > save the overhead of another message exchange in some cases.  Good 
> thing
> > WSA didn't kill wsa:From like they were thinking.  :-)
> >
> > thanks,
> > -Doug
> >
> >
> >
> > *Paul Fremantle <paul@wso2.com>*
> >
> > 10/05/2006 06:32 PM
> >
> >                  
> > To
> >                  "ws-rx@lists.oasis-open.org" 
> <ws-rx@lists.oasis-open.org>
> > cc
> >                  
> > Subject
> >                  [ws-rx] MessagePending
> >
> >
> >                  
> >
> >
> >
> >
> >
> > Rereading the spec around MakeConnection, I realize that we defined
> > MessagePending as only applicable on a message flowing back on a
> > MakeConnection backchannel. It seems to me that we could usefully add
> > this message in cases where a response is flowing on a back channel.
> >
> > For example. Suppose I have an interaction
> >
> > 1. GET1 ----->
> > <---- RESPONSE1
> >
> > 2. GET2----->
> > (response lost)
> >
> > 3. GET3----->
> > <------RESPONSE3
> >
> > In 3, the Get will have an ack for response1, and the server can
> > indicate that response 2 is missing.
> >
> > We already have logic to decide when piggybacking of acks is
> > appropriate. I believe the logic could be extended to decide when it was
> > ok to send back a MessagePending header:
> >
> > * In the sequenceID case, it would be appropriate whenever the message
> > being sent back was part of the same Offered response sequence.
> > * In the URI case, it would be appropriate whenever the replyTo URI
> > matched the MessagePending URI.
> >
> > Paul
> >
>