RE: State tables (reply 2)

[Peter Furniss <peter.furniss@choreology.com>]

Forgot to mention that there are implications in this for when the atom
coordinator knows about the cohesion composer - in particular when it knows
the BTP address of the composer. It has to know this before it persists the
atom information, as it will use the persistent information in recovery to
find out what the decision is, and will presume-abort cancel if it cannot
find evidence of a confirm decision. The atom coordinator *MAY* persist
information earlier, but the persistent information MUST be include the
recovery-callback address of the entity to whom the VOTE is sent, or the
VOTE will not be maintained in the case of failure

In many cases of course the atom will know its cohesion from before it
started.

Peter

> -----Original Message-----
> From: Mark Little [mailto:mcl@arjuna.com]
> Sent: 16 June 2001 22:05
> To: Peter Furniss; biztran - mainlist
> Cc: archive
> Subject: Re: State tables
>
>
> Peter, the state tables look fairly comprehensive, and I haven't had a
> chance to read through them in detail, so what I'm about to re-iterate may
> be implied in them. About two months ago when we started fleshing out the
> BTP I mentioned that a cohesion coordinator, i.e., that entity
> which decides
> to prepare atoms A, B, and C, for example, and then decides to
> cancel A and
> C and confirm B, should make persistent:
>
> (i) information about which atoms it was using that have been prepared.
>
> (ii) what decision it is about to make, i.e., cancel A and C, and
> confirm B.
>
> This is similar to the role an atom coordinator would play, except that an
> atom coordinator simply remembers all of its prepared participants and has
> the same decision associated with them all, whereby the cohesion
> coordinator
> potentially has different decisions for each participant atom.
>
> Mark.
>
> ----------------------------------------------
> Dr. Mark Little (mark@arjuna.com)
> Transactions Architect, HP Arjuna Labs
> Phone +44 191 2064538
> Fax   +44 191 2064203
>
>
>