Fw: [ws-tx] Issue 037 - WS-AT: Register/Preparing in coordinator statetable problematic

[Ian Robinson <ian_robinson@uk.ibm.com>]

Section 10 of WS-AT states:
"These tables present the view of a coordinator or participant with respect
to a single partner.  A coordinator with multiple participants can be
understood as a collection of independent coordinator state machines."

This is true for the representation of the 2PC protocol messages but, as
this issue points out and as we discussed at the F2F, is not obviously the
case for the Register/RegisterResponse messages which are used to establish
the relationships between Coordinator and Participant in the first place.
Given that Register/RegisterResponse are not actually part of the 2PC
protocol (as illustrated in the figure in section 4.3.3) I propose we
address this issue as follows:

1. Remove the 2 Register/RegisterResponse rows from the 2PC state tables.
2. Augment the text in section 4.3.1 so that we do not lose any information
as a result of removing these rows. The text currently states:
"Further participants may register with the coordinator until the
coordinator issues a Prepare to any durable participant."
I propose we insert the following text after this sentence:

"Once the Durable Two-Phase Commit Protocol has started any further
Register requests MUST be rejected with an InvalidState protocol fault
message."


- Ian

----- Forwarded by Ian Robinson/UK/IBM on 14/06/2006 22:22 -----
                                                                           
             "Ram Jeyaraman"                                               
             <Ram.Jeyaraman@mi                                             
             crosoft.com>                                               To 
                                       <ws-tx@lists.oasis-open.org>        
             28/03/2006 19:18                                           cc 
                                                                           
                                                                   Subject 
                                       [ws-tx] Issue 037 - WS-AT:          
                                       Register/Preparing in coordinator   
                                       state table problematic             
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




This is identified as WS-TX issue 037.

Please ensure follow-ups have a subject line starting "Issue 037 - WS-AT:
Register/Preparing in coordinator state table problematic".


From: Peter Furniss [mailto:peter.furniss@erebor.co.uk]
Sent: Monday, March 27, 2006 1:08 PM
To: ws-tx@lists.oasis-open.org
Subject: [ws-tx] New issue: WS-AT: Register/Preparing in coordinator state
table problematic

Issue name -- WS-AT: Register/Preparing in coordinator state table
problematic

PLEASE DO NOT REPLY TO THIS EMAIL OR START A DISCUSSISON THREAD UNTIL THE
ISSUE IS ASSIGNED A NUMBER.

The issues coordinators will notify the list when that has occurred.

Target document and draft:

Protocol:  WS-AT

Artifact:  spec

Draft:

AT spec cd 1

Link to the document referenced:

http://www.oasis-open.org/committees/download.php/17325/wstx-wsat-1.1-spec-cd-01.pdf

Section and PDF line number:

section 10, lines 503/504: table row Register, column Preparing


Issue type:

Design / Editorial


Related issues:

New issue: WS-AT: Coordinator state machine incomplete


Issue Description:

The cell Register/Preparing cannot be interpreted in a way that is
consistent with both the rest of the state table and with section 4.3.1
(lines 178-180).

Issue Details:

The states of the WS-AT have to be interpreted as the state of the
multi-lateral coordinator  - events occur that change the state of a
bilateral relationship, but do not not change the state in the table (see
issue Coordinator state machine unclear and incomplete).

Of the three cells that have different behaviour for volatile and durable
protocols, the two in the None state have to be understood to mean that a
message from a durable participant causes the Durable: behaviour, from a
volatile participant the Volatile: (since there is no modelled knowledge of
the participant, this has to be the case).

However, according to section 4.3.1 (and common practice in other
protocols), new registrations are permitted while volatile participants are
being prepared. The only way to interpret the Register/Preparing cell to
align with that would be to declare that the "Preparing" state is that of a
bilateral relationship, and the Volatile/Durable refers to the type of that
relationship, and not that in the Register.

This contradicts both the meaning of Volatile: Durable: in the other cells,
and the multi-lateral interpretation of the states.

Proposed Resolution:

This will be resolved if separate tables for the multilateral and bilateral
relationships are created as proposed for the issue WS-AT: Coordinator
state machine unclear and incomplete issue.