Re: [HACKERS] Fatal error after starting postgres : sys identifiers must be different

*I am not the best specialist about logical replication, but as it
looks to be a requirement to have 2 nodes with different system
identifiers, you shouldn't link 1 node to another node whose data
folder has been created from the base backup of the former (for
example create the 2nd node based on a base backup of the 1st node).
The error returned here would mean so.*
**
*- *I didn't create the /data folders from any backup for both the nodes;
they were created fresh by initdb individually. Is there anything specific
that I need to do apart from initdb?

*pgcontrol_data outputs different database system ids for the two nodes. So
> don't understand why it says identifiers are same.
Are you sure? Please re-ckeck.*
**
*- *I re-verified and they are different. Pasting the snapshots below-

irc1(at)ubuntuirc:~/bdr2/postgres-d6ed89e/postgres-bdr-bin/bin$
./pg_controldata ./data2/
pg_control version number: 937
Catalog version number: 201305061
Database system identifier: *5856368744762683487*
Database cluster state: in production
....

irc2(at)ubuntuirc2:~/bdr/postgres-bin/bin$ ./pg_controldata ./data/
pg_control version number: 937
Catalog version number: 201305061
Database system identifier: *5901663435516996514*
Database cluster state: in production

Also, am pasting the below snapshot to let you know that postgres doesn't
seem to be the su; in case this problem is due to that.

irc1(at)ubuntuirc:~/bdr2/postgres-d6ed89e/postgres-bdr-bin/bin$ ./psql testdb2
psql (9.3beta1)
Type "help" for help.
testdb2=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
irc1 | Superuser, Create role, Create DB, Replication | {}

irc2(at)ubuntuirc2:~/bdr/postgres-bin/bin$ ./psql testdb2
psql (9.3beta1)
Type "help" for help.
testdb2=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
irc2 | Superuser, Create role, Create DB, Replication | {}

Please let me know which mailing list will be more appropriate to raise my
concern regarding this postgres dev flavor.
I am yet to receive any response from Andres.

Thanks.

On Thu, Jul 18, 2013 at 3:31 PM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com>wrote:

> On Fri, Jul 19, 2013 at 5:02 AM, Indrajit Roychoudhury
> <indrajit(dot)roychoudhury(at)gmail(dot)com> wrote:
> > Could you please let me know what does the error "system identifiers are
> > same" mean? Below is the snapshot from one of the masters.
> > I am setting up BDR as per the wiki
> > http://wiki.postgresql.org/wiki/BDR_User_Guide#Initial_setup
> > and source @
> > git://git.postgresql.org/git/users/andresfreund/postgres.git
> >
> > irc1(at)ubuntuirc:~/bdr2/postgres-d6ed89e/postgres-bdr-bin/bin$ ./postgres
> -D
> > ~/bdr2/postgres-d6ed89e/postgres-bdr-bin/bin/data2/
> > LOG: bgworkers, connection: dbname=testdb2
> > LOG: option: dbname, val: testdb2
> > LOG: registering background worker: bdr apply: ubuntuirc2
> > LOG: loaded library "bdr"
> > LOG: database system was shut down at 2013-03-17 10:56:52 PDT
> > LOG: doing logical startup from 0/17B6410
> > LOG: starting up replication identifier with ckpt at 0/17B6410
> > LOG: autovacuum launcher started
> > LOG: starting background worker process "bdr apply: ubuntuirc2"
> > LOG: database system is ready to accept connections
> > LOG: bdr apply: ubuntuirc2 initialized on testdb2, remote dbname=testdb2
> > replication=true fallback_application_name=bdr
> > FATAL: system identifiers must differ between the nodes
> > DETAIL: Both system identifiers are 5856368744762683487.
> I am not the best specialist about logical replication, but as it
> looks to be a requirement to have 2 nodes with different system
> identifiers, you shouldn't link 1 node to another node whose data
> folder has been created from the base backup of the former (for
> example create the 2nd node based on a base backup of the 1st node).
> The error returned here would mean so.
>
> > LOG: worker process: bdr apply: ubuntuirc2 (PID 16712) exited with exit
> > code 1
> > ^CLOG: received fast shutdown request
> > LOG: aborting any active transactions
> > LOG: autovacuum launcher shutting down
> > LOG: shutting down
> >
> > pgcontrol_data outputs different database system ids for the two nodes.
> So
> > don't understand why it says identifiers are same.
> Are you sure? Please re-ckeck.
>
> > postgresql.conf content in one of the masters is like this-
> >
> > /////////////////
> > shared_preload_libraries = 'bdr'
> > bdr.connections = 'ubuntuirc2'
> > bdr.ubuntuirc2.dsn = 'dbname=testdb2'
> > /////////////////
> >
> > Two nodes are ubuntuirc and ubuntuirc2. Above is the output of the
> > postgresql.conf from ubuntuirc.
> If this behavior is confirmed, I think that this bug should be
> reported directly to Andres and not this mailing list, just because
> logical replication is not integrated into Postgres core as of now.
> --
> Michael
>