Re: More Slony questions

Raymond O'Donnell wrote:
> Hello again Dave et al.,
> 
> I'm still playing at intervals with setting up Slony-I replication via
> pgAdmin, and have a couple more questions -

Ah, congratulations - you've now used pgAdmin's Slony support more than
I have :-p

> (i) When you add nodes to a Slony cluster, does pgAdmin automagically
> register a slon service (I'm on Windows) and also run the "slon
> -addengine" command that's required on Windows to add a node? I ask this
> because, after creating a Slony cluster with two nodes, I see a service
> "Slony-I"  in Windows' "Services" list which I don't recall seeing there
> before (though that's not to say that it wasn't!) and wondered if
> pgAdmin had done it.

No, it doesn't. pgInstaller would have done it when you installed
PostgreSQL + Slony.

> To add to my confusion about the service, the command-line reported in
> the service properties is:
> 
>   C:\Program Files\PostgreSQL\8.2\bin\slon.exe -service
> 
> The -service switch is one which doesn't appear in the usage list given
> by "slon --help". What does it do, or where can I find out more?

It starts slon.exe in service mode. That should only happen when it's
started by the Service Control Manager which is why it's undocumented.

> (ii) What exactly is the "Admin node" in a cluster's properties in
> pgAdmin? - Is it simply a node in the cluster against which one would
> execute slonik scripts, if doing things by hand? Is it required?

It's a pseudo node that pgAdmin manages the cluster from. It is
required, unless you use Slonik only.

> Also, when looking at the properties of the cluster via the
> "Replication" treeview node of the master (source) database, the admin
> node is listed as the slave (target) node; but when looking at the
> properties of the same cluster via the slave database, the "Admin node"
> field says "None". Please help me make sense of all this!

To be honest I struggle with it myself. I'd just ignore that detail for
now and satisfy yourself with the fact that I hope to simplify things in
future versions :-)

Regards, Dave