Re: Minutes of MEP Task Force 2004-11-23

On Tue, 23 Nov 2004 14:04:37 -0500
David Booth <dbooth@w3.org> wrote:
> The bottom line is that I suggest -- actually JMarsh made this
> suggestion on the call, but I didn't manage to minute it in the midst
> of our debate :) -- that the service be permitted to characterize the
> fault either as a violation of its policies about where replies are
> permitted to be redirected or as an MEP violation.  How about letting
> the service characterize the fault in whatever way it sees fit?  

Violent agreement.

Sorry, I'm afraid that in the discussion, it must have appeared that
Roberto and I were saying that the service MUST do something,
specifically determine the node identity associated with both
origination address and reply-to address.  No.  I think it *is* possible
that a node could do so, and that, doing so, it could then feasibly
fault with the reason "MEP violation."  It could also have a set of
policies, associated with or independent of node identity association
with addresses, which could cause a fault in the same circumstances,
certainly (as well as, potentially, in other circumstances; policy
covers a wide territory).  Both faults are possible.  If our
disagreement during the call was based on the notion that we would
somehow require the service to perform some form of node-identity
checking, then I must have misspoken.  I would like the service to be
*permitted* to fault in this manner, if, by means unspecified, it
determines that the provided reply-to address is in fact *not*
associated with the requesting node.  That's all.

That in turn suggests that best practice is to characterize exchanges in
which the response is *expected* by both sides in the exchange to return
to the requesting node (for some definition of node identity), but that
if the service permits or expects the response to be directed to some
third node, then a different MEP should be advertised.

I think that most interactions are likely to be those in which the
service expects the response to return to the requester, so that our
publication of only that MEP is perfectly reasonable (although we
*could* provide the additional third-party in-out MEP; it wouldn't be
that difficult to show the binding in a non-normative note, for HTTP,
using WSA or WSMD or both).

Amy!
-- 
Amelia A. Lewis
Senior Architect
TIBCO/Extensibility, Inc.
alewis@tibco.com

Received on Tuesday, 23 November 2004 20:34:28 UTC