Re: Upgrading using streaming replication

Magnus Hagander wrote:
> On Fri, Mar 11, 2011 at 13:02, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > Damien Churchill wrote:
> >> Hi there,
> >>
> >> I have done quite a bit of searching but have been unable to find any
> >> way to do this. I am quite keen to use PostgreSQL 9.0's streaming
> >> replication to create a master/slave write/read setup. However I am
> >> unsure of an upgrade procedure whilst using streaming replication that
> >> doesn't yield any downtime (including being able to write). From what
> >> I have read the WAL won't be compatible between 9.0 and 9.1 so it
> >> won't be possible to take the slave off-line and upgrade it, promote
> >> it to master and then upgrade the old master.
> >>
> >> So I was wondering if anyone knows of a method that allows you to do
> >> this. Sorry if this is an often asked question and I just haven't been
> >> able to find the answer.
> >
> > Good question. ?I think you have to disconnect the slave, use pg_upgrade
> > to upgrade the master, and make a new slave. ?It is something we had not
> > considered. ?I don't think you can run pg_upgrade on the slave and have
> > it work.
>
> No, you can't. Because it gets a new systemid and things like that.
>
> If you use rsync to push from the master to the slave, the
> re-provisioning of the slave will be fairly quick, but again it's well
> above zero.

Ah, rsync is a good idea because most of the data is already there.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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