Issue 093 - WS-BA: Coordinator behavior upon Cancel/Completed racecondition

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

This issue is identified as 093.

Please use the subject line for future correspondence on this issue: "Issue 093 - WS-BA: Coordinator behavior upon Cancel/Completed race condition".
________________________________________
From: Ram Jeyaraman
Sent: Thursday, August 31, 2006 4:06 PM
To: ws-tx@lists.oasis-open.org
Subject: [ws-tx] NEW Issue - Coordinator behavior upon Cancel/Completed race condition

Protocol:  WS-BA

Artifact:  spec

Draft:  BA specification CD 02

Link to the document referenced:

http://www.oasis-open.org/committees/download.php/18818/wstx-wsba-1.1-spec-cd-02.pdf

Section and PDF line number: 249- 253

Issue type: design

Related issues:

Issue Description: WS-BA specification currently states the  following:


"The coordinator can enter a condition in which it has sent a protocol message and it receives a protocol

 message from the participant that is consistent with the former state, not the current state. In this case, it

is the responsibility of the coordinator to revert to the prior state, accept the notification from the

participant, and continue the protocol from that point. If the participant detects this condition, it must

discard the inconsistent protocol message from the coordinator."

In the case of Participantcompletion, the Cancel/Completed race condition is resolved in favor of the participant. That is, the coordinator will transition its internal state for the participant to Completed, and send forth a Compensate or Close message. The specification is not clear which message (Compensate or Close) is appropriate in this case; or is only Compensate the appropriate one. The spec should provide some guidance.

Given that the coordinator had previously sent a Cancel, it seems logical to send a Compensate (upon receiving Completed). However, one may argue that the coordinator may have changed its mind, and hence, Close is quite a valid message to be send (upon receiving Completed).

Proposed Resolution:
None.