On Fri, Jul 29, 2011 at 12:31 PM, Claire Chang
<claire at merchantcircle.com> wrote:
> hi,
> We have a slony cluster of 3 nodes running on postgres 8.3 and slony 1.2.15.
> We'd like to add a new slony node running on 8.4. When I tried to compile
> slony 1.2.15 against postgres 8.4, I got compilation errors. I guess the
> only choice I have is to upgrade slony to 1.2.22.

I've run into this in the past.  when your version of slony is older,
it might predate the version of pg you're wanting to run.  Pretty sure
8.4 is from way after 1.2.15.  So that's normal.

> I read the update documentation. It seems like it is relative safe and easy
> to upgrade slony. Just need to update the slony binaries and run update
> functions.

Yep, it's pretty straight ahead.

> Does any one successfully run a cluster of both 8.3 and 8.4 nodes?

I've run a cluster with both 8.1 and 8.3 and later a cluster with 8.3
and 8.4.  both worked wonderfully. It's a great way to upgrade in
place without much downtime.

> Is 1.2.22 very stable? Any known issues?

I run 1.2.21 and it's been ULTRA stable for me.  The only issue 1.2.x
has that 2.0.x might help me on is having tens of thousands of objects
in the schema on the master.  This does not work well with 1.2.x due
to overly aggressive locking etc.


> I intended to choose the first method since it looks easier. What are the
> risks of doing the 1st method?

There aren't any I'm aware of.  It's how I do slony at work, since we
have an odd mixture of RHEL5, Ubuntu 8.04 and Ubuntu 10.04 database
servers to keep synced up.

> And it is impossible to do this (have one packaged version of slony?? ed) when there
> are multiple versions of postgreSQL in the same cluster. Is my understanding
> correct?

Yeah pretty much.  If you're running > 1 major versions of pg you'll
be needing to build from source.  It's not too hard not scary tho.