Re: Upgrading using streaming replication

Damien Churchill wrote:
> On 11 March 2011 12:04, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
> > On Fri, Mar 11, 2011 at 12:58, Damien Churchill <damoxc(at)gmail(dot)com> 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.
> >
> > That's correct, you can'd do that.
> >
> >
> >> 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.
> >
> > Using SR, the method will be to upgrade the master and then rebuild
> > the slave off that one. You can upgrade with pg_upgrade, which will
> > shorten your downtime, but there will be downtime.
> >
> > For a downtime-less upgrade, you will need to look at one of the
> > "userspace replication solutions", like slony, bucardo, londiste etc.
> >
>
> Thanks for the response!
>
> That's the conclusion I had come to as well, I thought it best to ask
> in case there was a method I hadn't come across. Is anything planned
> to allow SR to be used for downtime-less upgrades, or will using one
> of the other replication solutions be the only way for the foreseeable
> future?

I don't know of any plans to allow downtime-less upgrades with streaming
replication.

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

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