Re: dbmirror

I recall recently seeing something in the CVS logs for dbmirror about the
sequence replication capability having been added, so you might check on
that.


On Friday May 14 2004 7:11, Fred Fung wrote:
> Thanks for all your comments.
>
> Is it really true that the sequences in the tables in the Slaves will not
> be in sync with those in the Master ? If so then this is a show-stopper
> factor for us to consider using dbmirror, as we use sequences as a unique
> key in many of the tables in our application.
>
> What is Slony-I ? Is it a commerical software ? Is there a website I can
> read more about it ?
>
>
> Thanks.
>
>
> Fred
>
>
> ----- Original Message -----
> From: "Gregory Wood" <gwood@ewebengine.com>
> To: "Andrew Sullivan" <ajs@crankycanuck.ca>
> Cc: <pgsql-general@postgresql.org>
> Sent: Thursday, May 13, 2004 4:10 PM
> Subject: Re: [GENERAL] dbmirror
>
> > Does dbmirror do that? No, it does not. It also doesn't support
> > promoting a slave database to a master; that has to be done manually,
> > so I wouldn't consider that too big a problem.
> >
> > Worse in my opinion is that sequences don't get updated... so a slave
> > that tries to do an insert on a replicated table (for example, when it
> > gets manually promoted to master) will find the sequence not where the
> > master left it, but where it was loaded. Every sequence has to be
> > manually updated before the database is usable.
> >
> > dbmirror was never intended to be anything but a poor man's
> > replication... and it worked remarkably well for that purpose. Now it's
> > time to look forward to Slony-I :)
> >
> > Greg
> >
> > Andrew Sullivan wrote:
> > > On Wed, May 12, 2004 at 05:53:05PM -0700, Gregory S. Williamson wrote:
> > >>Fred --
> > >>
> > >>Yes, the slave database(s) can be safely used in a R/O mode,
> > >
> > > Does it also block write transactions in those slaves?  The ability
> > > for clients to write into the slave replicated tables is a problem,
> > > because it makes promoting a slave node somewhat risky.
> > >
> > > Slony-I has a trick to solve this problem, BTW.
> > >
> > > A
> >
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