Re: Easy upgrade on Cpanel *without* downtime

On 8/26/08, Phoenix Kiula <phoenix(dot)kiula(at)gmail(dot)com> wrote:
> On 8/26/08, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
> >
> > Slony replication lets postgresql accomplish this, which is really
> > quite impressive. We just upgraded from an 8.1 server to an 8.3
> > server via slony, and it went smooth as silk. db downtime was
> > measured in seconds.
>
>
>
>
> Thanks for this Scott. Sounds promising. But where can I find the
> instructions to install Slony, then install new PG 8.3.3, then start
> it with similar CONF settings and stuff, then setup the master and
> slave (which I am not familiar with), and then switch master and slave
> when everything is working?
>
> To others who keep telling us that "PG is complex and if you want it
> to be less so then contribute" -- well, sorry I am not that technical.
> If the intended target audience of PG is only super-techsavvy folk who
> can write C++ patches for every little functionality they need, then
> perhaps I chose the wrong DB? I doubt it.
>
> It would be really nice if the PG official community can have some
> simple instructions to make a seamless upgrade, if no simpler patches
> exist. At the very least the instructions will help us plentiful folk
> who do NOT use PG in the exalted "enterprise" setting, but to run busy
> websites. This is how MySQL became big too, by being convenient and
> reliable (until recently anyway), but I see no point in that
> discussion.
>
> Anyhow, it would be really nice to have simple instructions. Searching
> on Google for words like "Slony Postgresql upgrade" or "install slony
> with postgresql 8.3" returns stuff that makes a lot of presumptions!
>
> I have a CentOS 4 with Cpanel/WHM running. PG is in the usual place:
>
> > whereis pgsql
> pgsql: /usr/lib/pgsql /usr/include/pgsql /usr/share/pgsq
>
> Now how can I install Slony so that it install PGSQL and allows me to
> continue working with Apache/PHP for my website? I am reading this --
> http://slony.info/documentation/installation.html -- but while it
> textually mentions the stuff in the writeup, I don't see full
> instructions to install Slony, then new PGSQL, then switching, and so
> on.
>
> So many thanks for any help anyone can provide! Or point me to some
> resource that exists but is hiding from Google.
>

See, this is where I get confused. I want to upgrade from 8.2.3 to
8.3.3. The recommendation is to try Slony. So I download Slony and try
to configure it. The configure command gives me this:

----
checking for correct version of PostgreSQL... "error"
configure: error: Your version of PostgreSQL (8.2) is lower
than the required 8.3. Slony-I needs functionality included in
a newer version.
----

Well, if Slony needs a newer version, then how can it be used to upgrade?!