Re: 2-phase commit - Mailing list pgsql-hackers

From Marc G. Fournier
Subject Re: 2-phase commit
Date
Msg-id 20030926153102.W77053@ganymede.hub.org
Whole thread Raw
In response to Re: 2-phase commit  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: 2-phase commit
List pgsql-hackers

On Fri, 26 Sep 2003, Tom Lane wrote:

> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Tom Lane wrote:
> >> You're not considering the possibility of a transient communication
> >> failure.
>
> > Can't the master re-send the request after a timeout?
>
> Not "it can", but "it has to".  The master *must* keep hold of that
> request forever (or until the slave responds, or until we reconfigure
> the system not to consider that slave valid anymore).  Similarly, the
> slave cannot forget the maybe-committed transaction on pain of not being
> a valid slave anymore.

Hrmmmm ... is there no way of having part of the protocol being a message
sent back that its a valid/invalid slave?  ie. slave has an uncommitted
transaction, never hears back from master to actually do the commit, so
after x-secs * y-retries any messages it does try to send to the master
have a bit flag set to 'invalid'?



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