--- On Mon, 11/5/09, Christopher Browne <cbbrowne at ca.afilias.info> wrote:

> From: Christopher Browne <cbbrowne at ca.afilias.info>
> Subject: Re: [Slony1-general] MOVE SET confusion
> To: glynastill at yahoo.co.uk
> Cc: slony1-general at lists.slony.info
> Date: Monday, 11 May, 2009, 3:51 PM
> Glyn Astill <glynastill at yahoo.co.uk> writes:
> > Hi chaps,
> >
> > We have a setup with 3 nodes. Initially nodes 2 and 3
> were subscribed to 1, but last night I moved the origin to 2
> as per the docs.
> >
> > All seems to be well, but I'm confused with what
> the logs are showing. Node 1 has the following in it's
> logs for each set;
> >
> > remoteWorkerThread_2: syncing set 2 with 43 table(s)
> from provider 2
> >
> > But node 3 is saying this;
> >
> > remoteWorkerThread_2: syncing set 2 with 43 table(s)
> from provider 1
> >
> > Surely when I moved the origin from node 1 to 2, both
> nodes should be syncing from node 2?
> >
> > Anyone?
> 
> Why should this be "surely"?
> 
> The subscription chain from the old origin to the new
> origin is
> reversed (see
> <http://slony.info/documentation/stmtmoveset.html>).
> 
> The subscriptions for node #3 are only revised if they are
> members of
> the chain from the old origin to the new one.  Since [1,3]
> is not part
> of the [1,2] chain, there is no need to do so.

I think I just had the wrong picture of the operation in my head then. I assumed that a move set where node 1 is the origin and both nodes 2 and 3 subscribe to 1, i.e.

2---> 1 <---3

Would also move subscription along with the location of the origin set because node 1 was set as the provider for both nodes 2 and 3, i.e.

1---> 2 <---3

Obviously this isn't the way it's designed and to get that behavior I'd have to use the subscribe set command as well.

I guess this outlines the importance of understanding the difference between provider and origin when using move set then. 

You are *only* moving the origin of the set and *not* the provider. The provider only changes between the new and old origin. Correct?