Issue 077 - WS-AT: Make completion protocol request-reply, permitting anon

["Ram Jeyaraman" <Ram.Jeyaraman@microsoft.com>]

This is identified as WS-TX issue 077.

Please ensure follow-ups have a subject line starting "Issue 077 -
WS-AT: Make completion protocol request-reply, permitting anon".

-----Original Message-----
From: Alastair Green [mailto:alastair.green@choreology.com] 
Sent: Monday, July 10, 2006 7:09 AM
To: ws-tx@lists.oasis-open.org
Subject: [ws-tx] NEW ISSUE: WS-AT: Make completion protocol
request-reply, permitting anon

My apologies to the committee. I overlooked sending this issue in before
the deadline -- it was one I had noted down from the Dublin
face-to-face, and I had intended to put it in with the WS-BA batch. I
hope the TC will stretch a point on Friday's deadline... Thanks,
Alastair

Issue name -- WS-AT: Make completion protocol request-reply, permitting
anon

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Target document and draft:

Protocol:  WS-AT

Artifact:  spec

Draft:  AT spec cd 2

Link to the document referenced:

http://www.oasis-open.org/committees/download.php/18888/wstx-wsat-1.1-sp
ec-cd-02.doc


Section and PDF line number: 

Section 4.2 "Completion Protocol"; Section 9, "Use of WS-Addressing
Headers"

Issue type:  Design


Related issues:


Issue Description:

A client that initiates a transaction using WS-Coordination
CreateCoordinationContext can do so using one-ways, or the anonymous
back-channel. The latter facility was added to permit "thin clients"
(ones that cannot listen for inbound
messages) to initiate an activity. Such a client is likely to have
responsibility for terminating the transaction, and it would therefore
be appropriate to make the completion protocol have the same
characteristics.

Issue Details

An interoperable client program is very likely to wish to conduct the
following sequence of actions: 

a) send CreateCoordinationContext to the Activation Service of a
Coordination Service
b) send Register for the AT Completion Protocol to the Registration
Service of a Coordination Service
c) send AT Completion Protocol Commit or Rollback to the Coordinator for
the activity within the Coordination Service.

It was accepted at the Dublin F2F that activities a) and b) should be
allowed to use the anonymous back channel for the CCCResponse and
RResponse replies, allowing the client program to be a thin client, i.e.
one that is unable to listen for unsolicited inbound messages.

It seems illogical to prevent a thin client conducting all three of the
actions in this common sequence. The inability to do c) is likely to
vitiate the purpose of the accepted change allowing such a client to
enact a) and b).


Proposed resolution


Specify that WS-AT Completion Protocol has the same addressing
characteristics as WS-Coordination, i.e. that the [reply endpoint]
property is used to indicate the target of the expected response, and
that that endpoint reference is permitted to have the WS-A anonymous URI
as its URI.