The solution was found thanks to Petr Jelinek from 2ndQ.
> Cascading wasn't much of a priority so far.
> Currently you have to create the origin manually using pg_replication_origin_create().
> I plan to make this work seamlessly in the future release.
So whats needed to be done is:
on p2:
select * from pg_replication_origin;
will show all origins on p2, find the origin for p1;
on p3:
select pg_replication_origin_create('[origin name]');
Discussed here:
https://github.com/2ndQuadrant/pglogical/issues/23
Please ignore previous message;
Regards,
Nick.