Re: [ws-tx] Issue 061 - WS-AT: Spontaneous preparation/resignation/abortionof participant

[Alastair Green <alastair.green@choreology.com>]

Subject to detailed check on resolution, I'll go with this (i.e. I don't 
want to pursue eager preparation).

Thanks,

Alastair

Ram Jeyaraman wrote:
>
> Spontaneous abortion and resignation of participants (PV state table 
> changes) as proposed in the issue resolution is consistent with the 
> behavior detailed in the CV table.
>
> However, spontaneous preparation is a new behavior; it is unclear why 
> this is useful. Further, to my knowledge, legacy resource managers do 
> not actually support eager preparation.
>
> Proposed resolution:
>
> Section 10 State tables, PV state table:
>
> 1. Row ‘Rollback decision’, column ‘Active’: change to ‘Send Aborted / 
> Aborting’
>
> 2. Row ‘All Forgotten’, column ‘Active’: change to ‘Send ReadOnly / None’
>
> *From:* Ram Jeyaraman [mailto:Ram.Jeyaraman@microsoft.com]
> *Sent:* Wednesday, May 31, 2006 11:53 PM
> *To:* ws-tx@lists.oasis-open.org
> *Subject:* [ws-tx] Issue 061 - WS-AT: Spontaneous 
> preparation/resignation/abortion of participant
>
> This is identified as WS-TX issue 061.
>
> Please ensure follow-ups have a subject line starting "Issue 061 - 
> WS-AT: Spontaneous preparation/resignation/abortion of participant".
>
> ------------------------------------------------------------------------
>
> *From:* Alastair Green [mailto:alastair.green@choreology.com]
> *Sent:* Wednesday, May 31, 2006 2:36 AM
> *To:* ws-tx@lists.oasis-open.org
> *Subject:* [ws-tx] NEW ISSUE -- WS-AT: Spontaneous 
> preparation/resignation/abortion of participant
>
> Issue name -- WS-AT: Spontaneous preparation/abortion/resignation of 
> participant
>
> PLEASE DO NOT REPLY TO THIS EMAIL OR START A DISCUSSION THREAD UNTIL 
> THE ISSUE IS ASSIGNED A NUMBER.
>
> The issues coordinators will notify the list when that has occurred.
>
> Protocol: WS-AT
>
> Artifact: spec
>
> Draft:
>
> WS-AT CD 0.1 uploaded
>
> Link to the document referenced:
>
> http://www.oasis-open.org/apps/org/workgroup/ws-tx/download.php/17325/wstx-wsat-1.1-spec-cd-01.pdf
>
> Section and PDF line number
>
> Section 10, "State Tables", Coordinator View table, between ll. 503 
> and 504, and Participant View table following
>
>
> Issue type: Design
>
>
> Related issues: None
>
>
> Issue Description:
>
> PV state table appears to prohibit rollback decision in Active state, 
> tho' CV would accept message if sent. Same applies to ReadOnly.
>
>
> Issue Details:
>
> PV state table Row Rollback Decision, State Active, N/A -- means 
> cannot occur. This implies that participant can never make decision to 
> abort until it has received Prepare. But Expires Times Out generates 
> spontaneous abort: it is safe against the CV table. Not clear why P 
> cannot abort prior to receiving Prepare.
>
> Similarly: PV state table All Forgotten, State Active, N/A -- means 
> cannot occur. This implies that participant cannot go read-only until 
> it has received Prepare.
>
> CV state table Row Aborted, State Active, action: Forget; state 
> Aborting. This cell cannot be entered if Prepare has already been sent 
> (wd be in state Preparing). But PV can only send if expires times out.
>
> CV state table Read Only, State Active, action: Forget; state Active. 
> This cell cannot be entered: if Prepare has already been sent C would 
> be in state Preparing. PV cannot send Read Only in Active state..
>
> Therefore, CV in Active state is able to accept messages that PV can 
> never send (Read Only) or that it can only send in a very restricted 
> circumstance.
>
> >From the standpoint of correctness and speed of transaction 
> resolution, there is no argument against allowing Participants to 
> spontaneously prepare (q.v. Gray/Lamport, "Paxos Commit"), vote 
> rollback, or go read-only (i.e. to make these decisions prior to 
> receiving Prepare).
>
>
> Proposed Resolution:
>
> Alter state tables to permit spontaneous preparation, abortion and 
> resignation, as per attached Word document.
>
> If this is not accepted, the un-enterable cell (Read Only/Active) in 
> CV needs to be set to N/A.
>