Re: [ws-rx] NEW ISSUE: retransmission

[Doug Davis <dug@us.ibm.com>]

I think the new bullet is ok  -
but since Acks can be sent even after the Sequence is closed I think the
change to line 230 is a bit misleading.  Perhaps the original text
for that is still ok?
-Doug

Paul Fremantle <paul@wso2.com>

11/03/2006 03:12 AM

To	Doug Davis/Raleigh/IBM@IBMUS
cc	"Patil, Sanjay" <sanjay.patil@sap.com>, Gilbert Pilz <Gilbert.Pilz@bea.com>, ws-rx@lists.oasis-open.org
Subject	Re: [ws-rx] NEW ISSUE: retransmission

Yeah I was struggling with that. I agree.

Proposal (stolen from Gil and Sanjay):

Change line 230 to read:

"While the Sequence is not closed or terminated, the following 
invariants are REQUIRED for correctness:"

Then add new bullet to be inserted after line 238 to read:
"The RMS MUST retransmit unacknowledged messages".

Paul

Doug Davis wrote:
>
> Paul - your latest version:
> >"The RMS MUST retransmit any messages that are unacknowledged
in any
> >received SequenceAcknowledgement messages".
> can be read to impl that if I get an Ack for 1,3 and then an Ack for
> 1,2,3 I MUST still send
> message 2 because of the 2nd "any".
> I agree with Sanjay, I think the simpler sentence actually covers
it 
> better.
>
> thanks,
> -Doug
>
>
>
> *"Patil, Sanjay" <sanjay.patil@sap.com>*
>
> 11/02/2006 07:52 PM
>
>                  
> To
>                  "Paul
Fremantle" <paul@wso2.com>, Doug Davis/Raleigh/IBM@IBMUS
> cc
>                  "Gilbert
Pilz" <Gilbert.Pilz@bea.com>, <ws-rx@lists.oasis-open.org>
> Subject
>                  RE:
[ws-rx] NEW ISSUE: retransmission
>
>
>
>                  
>
>
>
>
>
>
> Paul,
>
> I thought your very first suggestion was simpler and sufficient --
> "The RMS MUST retransmit unacknowledged messages".
>
> Why do we need to say more? Isn't receiving SeqAck the only way to
> confirm acks?
>
> -- Sanjay
>
> >-----Original Message-----
> >From: Paul Fremantle [mailto:paul@wso2.com]
> >Sent: Thursday, Nov 02, 2006 16:46 PM
> >To: Doug Davis
> >Cc: Gilbert Pilz; ws-rx@lists.oasis-open.org
> >Subject: Re: [ws-rx] NEW ISSUE: retransmission
> >
> >Ah good point.
> >
> >I was trying to distinguish between positively unacked
> >messages (I have
> >an ack but it doesn't include message 3) and the situation where
I
> >haven't yet got an ack.
> >
> >Is this any better?
> >"The RMS MUST retransmit any messages that are unacknowledged
in any
> >received SequenceAcknowledgement messages".
> >
> >Paul
> >
> >Doug Davis wrote:
> >>
> >> Well, since Acks can be received out of order I don't think
you want
> >> to say "most recent".
> >> I think sticking with just talking about "unacked"
messages is safer.
> >> thanks,
> >> -Doug
> >>
> >>
> >>
> >> *"Gilbert Pilz" <Gilbert.Pilz@bea.com>*
> >>
> >> 11/02/2006 07:35 PM
> >>
> >>                  
> >> To
> >>                  "Paul
Fremantle" <paul@wso2.com>, 
> <ws-rx@lists.oasis-open.org>
> >> cc
> >>                  
> >> Subject
> >>                  RE:
[ws-rx] NEW ISSUE: retransmission
> >>
> >>
> >>
> >>                  
> >>
> >>
> >>
> >>
> >>
> >> May I suggest ammending your proposal in the following way:
> >>
> >> Change line 230 to read:
> >>
> >> "While the Sequence is not closed or terminated, the
following
> >> invariants are REQUIRED for correctness:"
> >>
> >> Then change the new bullet to be inserted after line 238
to read:
> >>
> >> "The RMS MUST retransmit any messages that are missing
from the most
> >> recent Acknowledgement Message".
> >>
> >> - gp
> >>
> >> " . . and nice red uniforms."
> >>
> >> > -----Original Message-----
> >> > From: Paul Fremantle [mailto:paul@wso2.com]
> >> > Sent: Thursday, November 02, 2006 3:40 PM
> >> > To: ws-rx@lists.oasis-open.org
> >> > Subject: [ws-rx] NEW ISSUE: retransmission
> >> >
> >> > We do not normatively state that any messages must be
> >> > retransmitted unless the server Nacks them.
> >> >
> >> > Since the Protocol Invariants are there to explain how
we
> >> > actually ensure reliable transmission, that is the
> >> > appropriate place to add this.
> >> >
> >> > Proposal:
> >> >
> >> > Add a new invariant:
> >> > While the Sequence is not closed or terminated, the
RMS must
> >> > retransmit any messages that are missing from the most
recent
> >> > acknowledgement message.
> >> >
> >> >
> >> >
> >> > -------- Original Message --------
> >> > Subject:              
   [ws-rx] Potential new issue:
> >retransmission
> >> > Date:              
   Wed, 01 Nov 2006 12:22:25 +0000
> >> > From:              
   Paul Fremantle <paul@wso2.com>
> >> > Organisation:            
     WSO2
> >> > To:              
   ws-rx@lists.oasis-open.org
> >> <ws-rx@lists.oasis-open.org>
> >> >
> >> >
> >> >
> >> > While looking at PR016, I could only find three places
where we
> >> > normatively define retransmission:
> >> >
> >> > 1. Upon receipt of a NACK, you must retransmit that
message
> >> > 2. Upon MessageNumberRollover, you must continue to
> >> > retransmit messages
> >> > 3. In the state tables, we have a state corresponding
to this.
> >> >
> >> > Given that NACK is optional, MessageNumberRollover highly
unlikely,
> >> > doesn't seem like we've defined this very well!
> >> >
> >> > How about adding as a protocol invariant that the RMS
must
> >retransmit
> >> > unacknowledged messages?
> >> >
> >> > Paul
> >> >
> >> > --
> >> > Paul Fremantle
> >> > VP/Technology and Partnerships, WSO2
> >> > OASIS WS-RX TC Co-chair
> >> >
> >> > http://bloglines.com/blog/paulfremantle
> >> > paul@wso2.com
> >> > (646) 290 8050
> >> >
> >> > "Oxygenating the Web Service Platform", www.wso2.com
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> > Paul Fremantle
> >> > VP/Technology and Partnerships, WSO2
> >> > OASIS WS-RX TC Co-chair
> >> >
> >> > http://bloglines.com/blog/paulfremantle
> >> > paul@wso2.com
> >> > (646) 290 8050
> >> >
> >> > "Oxygenating the Web Service Platform", www.wso2.com
> >> >
> >> >
> >> >
> >>
> >
> >--
> >Paul Fremantle
> >VP/Technology and Partnerships, WSO2
> >OASIS WS-RX TC Co-chair
> >
> >http://bloglines.com/blog/paulfremantle
> >paul@wso2.com
> >(646) 290 8050
> >
> >"Oxygenating the Web Service Platform", www.wso2.com
> >
> >
> >
>

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

http://bloglines.com/blog/paulfremantle
paul@wso2.com
(646) 290 8050

"Oxygenating the Web Service Platform", www.wso2.com