On Wed, 2 Apr 2008, Craig James wrote:

> Jeff Frost wrote:
>> On Wed, 2 Apr 2008, Craig James wrote:
>> 
>>> I keep getting this error:
>>>
>>>  remoteListenThread_1: db_getLocalNodeId() returned 2 - wrong database?
>>> 
>>> I suspect the slon daemon can't handle port numbers correctly.  In this 
>>> case, both the master and slave databases have the same name, AND the same 
>>> host. The only difference is the port number.
>>> 
>>> When I start slon, it seems to try to figure out the node number from the 
>>> combination of dbname+host, but it seems to ignore the port number, so it 
>>> arbitrarily will get node 1 or node 2.
>>> 
>>> (In case you're wondering, the second database is actually on a different 
>>> machine, accessed via an encrypted ssh(1) tunnel that maps port 5433 on 
>>> the local machine to port 5432 on the remote machine.  So the two 
>>> databases are accessed by the same name and same host, with only the port 
>>> to distinguish them.)
>>> 
>>> Is my analysis correct?  How does the slon daemon figure out which node 
>>> number it is working on?  There doesn't seem to be any way to tell it.
>> 
>> It calls the getlocalnodeid(name) function on the DB specified in the 
>> conninfo when it's started.
>> 
>> How are you providing the conninfo to the slon daemons?
>
> The same string I used to create the nodes, for example, here are the master 
> and slave, respectively:
>
> Node 1 (master): slon -d 1 my_db_cluster 'dbname=my_db host=au user=postgres 
> port=5433'
> Node 2 (slave):  slon -d 1 my_db_cluster 'dbname=my_db host=au 
> user=postgres'
>
> I also tried to make up a dummy hostname "au2", just to make them look 
> different.  After deleting both nodes and rebuilding them with the different 
> server names:
>
> Node 1 (master): slon -d 1 my_db_cluster 'dbname=my_db host=au2 
> user=postgres port=5433'
> Node 2 (slave):  slon -d 1 my_db_cluster 'dbname=my_db host=au 
> user=postgres'
>
> but I still get the error.  This is a bit baffling.  I can't really see 
> what's different than the other Slony configurations I've set up, other than 
> that I've never used port numbers before.

I've replicated to a different PostgreSQL instance on the same host in the 
past, so I would expect your setup to work fine.

Don't you have to connect to localhost port 5433 for the ssh port forward to 
work or does host 'au' resolve to 127.0.0.1?

What does the output of this look like:

netstat -an | grep 543[23]

and better yet, can you connect to both of them on the machine where the slons 
will run like this:

psql -h au -p 5433 -U postgres my_db
psql -h au -p 5432 -U postgres my_db

and if so, what's the output of:

select _my_db_cluster.getlocalnodeid('_my_db_cluster');

on both those?

-- 
Jeff Frost, Owner 	<jeff at frostconsultingllc.com>
Frost Consulting, LLC 	http://www.frostconsultingllc.com/
Phone: 650-780-7908	FAX: 650-649-1954