well i
think ws-n should define boxcar messages as being delivered atomically,
otherwise we have to define our own dissasembly/reassembly mechanism and I for
one don't want to go there!
Martin.
Martin Chapman wrote:
Boxcarring means that notify messages are bundled in a single soap
message. ws-rx works at the soap level so it doesn’t need to know about
boxcarring of notify messages.
Right. So it looks not to be the tool I'd need if I
wanted each notification to have its own delivery status.
The question
is not so much what WS-RX does, but what semantics should we
define. In particular, are we producing and delivering SOAP envelopes or
notifications? Naturally, I lean toward the latter.
FWIW, I'm
more and more convinced that there should be some sort of SOAP-level
boxcarring standard that allows multiple SOAP envelopes to be sent
transparently in a single wrapper (most likely itself a SOAP envelope).
This should be able to compose with the other WS-*, so that it would be
possible to acknowledge individual messages that happened to travel in the
same wrapper (or authorize/authenticate each separately, or re-route them to
different places, or whatever).
Martin.
-----Original Message-----
From: David Hull [mailto:dmh@tibco.com]
Sent: Wednesday, January 04, 2006 10:32 PM
To: wsn@lists.oasis-open.org
Subject: [wsn] Boxcarring and reliability
Following the example of the reliability specs, we distinguish
between producing and delivering. If we boxcar a set of
Notifications in a Notify message, are they required to be
delivered atomically? IMHO, boxcarring is a transport-level
optimization and atomicity should be handled separately (it
should be possible to handle a set of messages atomically even
if they happen to be transmitted in different SOAP envelopes).
Ideally, each of the boxcarred messages would have its own
delivery status. E.g., I am able to process the first five of
ten boxcarred messages and acknowledge them, and then my
process crashes or the network goes down. To accomplish this,
though, the reliability layer would have to know about the
boxcarring. This argues for handling boxcarring outside WSN
(WS-Boxcarring, anyone? WS-Polling is already underway ...)
Thoughts?
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