Re: setting up streaming replication

>
> On Oct 23, 2023 at 8:30 PM, Ron <ronljohnsonjr(at)gmail(dot)com> wrote:
>
>
> On 10/23/23 18:16, Brad White wrote:
> > I'm stumped.
> >
> > Using this command to set up the slave and replication on PG v 15:
> > "C:\Program Files\PostgreSQL\15\bin\pg_basebackup" -h 192.168.1.126 -U
> > pgrep_user -p 5433 -D "C:\Program Files\PostgreSQL\15\data" -Fp -Xs -R
> >
> > If I have PG running on the remote server and the data directory is
> > intact, then I get an error, Data exists and is not empty.
> >
> > If I shut down PG, delete data\*, restart PG, then it fails to start
> > because the conf files are missing.
> >
> > If I leave PG shut down and run pg_basebackup, it times out and asks if pg
> > is running and listening on the port. Of course it is not.
> >
> > I see lots of posts on how to use pg_basebackup, but apparently this isn't
> > interesting because no one mentions whether pg should be running on
> > the remote server.
>
> No, it should not.
>
> This is what works for me, in Linux on the standby system, where "buddy" and
> "basebackup" are references in .pg_service.conf to the primary server:
> PGHOST=...
> pg_ctl status && pg_ctl stop -mfast
> psql service=buddy -Xac "select pg_drop_replication_slot(slot_name)
> from pg_replication_slots
> where slot_name = 'pgstandby1';"
> /usr/bin/rm -r $PGDATA/*
> pg_basebackup --dbname=service=basebackup -D $PGDATA --progress \
> --checkpoint=fast -v \
> --write-recovery-conf --wal-method=stream \
> --create-slot --slot=pgstandby1 --compress=server-zstd
> pg_ctl start -wt90 -l ${MajVer}/pgstart_standby.log
>
> Source:
> https://www.tecmint.com/configure-postgresql-streaming-replication-in-centos-8/
>
>
> It sounds like you are saying that pg_basebackup should be run on the backup server, not on the primary. But a detail that important would be mentioned in the documentation. Especially since it is directly compared to pg_dump, which I only run on the primary.
>
> If you are running it from the secondary, how can you have a pg_service.conf since data is empty?
>
> Is all that stuff with slots necessary since the backup will automatically create a temporary slot for replication?
>
>
>
> Thanks,
>
> Brad.