Re: Create a standby server

Greetings,

On Mon, Mar 11, 2024 at 13:33 normandavis1990 <normandavis1990(at)proton(dot)me>
wrote:

> > On Monday, March 11th, 2024 at 3:43 PM, Stephen Frost <
> sfrost(at)snowman(dot)net> wrote:
>
> > Greetings,
> >
> > * normandavis1990 (normandavis1990(at)proton(dot)me) wrote:
> >
> > > I have a master and tow standby servers. I want to create another
> one. These servers are made by someone else and I am a newbie in PostgreSQL.
> > > I found the following two tutorials:
> >
> >
> > [...]
> >
> > > A) Which on is better and easier?
> >
> >
> > One referred to 9.2, which is extremly old and no longer supported, and
> > the other said it was archived ... so I'm not sure either is really
> > great to be used today.
> >
> > > B) In these articles, to create a Standby server, a user is created in
> the database. Because there are already two Standby servers, this user is
> probably created. How can I find it? Can I use that user to build a third
> server?
> >
> >
> > If those systems are connected to the primary, you can query the view
> > pg_stat_replication and see what user they are connected with:
> >
> > SELECT * FROM pg_stat_replication;
> >
> > You should be able to use the existing user to create a new standby.
> > I'd recommend using pg_basebackup to create it with a command along
> > these lines:
> >
> > pg_basebackup -h existing.server.com -U username -D
> /destination/directory -c fast -C -S standbyslotname -R -P -v
> >
> > Running pg_basebackup this way will:
> > - Have pg_basebackup connect to 'existing.server.com' (should be your
> > primary)
> > - Connect as user 'username' (pull this from the 'usename' field in
> > pg_stat_replication)
> > - Store the data files for the new system into /destination/directory on
> > the system where pg_basebackup is run
> > - Start the backup immediately by doing a 'fast' checkpoint
> > - Create a replication slot to use to make sure the WAL is kept on the
> > primary until the new standby system collects it (you should monitor
> > this though- if you destroy this new system, WAL could build up on the
> > primary).
> > - Use 'standbyslotname' as the name of the slot that's created
> > - Instructs pg_basebackup to write out the connection information to
> > connect to the primary and start streaming when it starts up.
> > - Enabled progress reporting from pg_basebackup
> > - Enables verbose mode of pg_basebackup
> >
> > Full documentation of pg_basebackup is here:
> >
> > https://www.postgresql.org/docs/current/app-pgbasebackup.html
> >
> > Thanks!
> >
> > Stephen
>
> Hi,
> Thank you.
> Shoudd I run the following command on the mater?
>
> $ pg_basebackup -h "Master_IP_Address" -U username -D
> /destination/directory -c fast -C -S standbyslotname -R -P -v

No, on the system you wish to bring up as another standby.

Thanks,

Stephen

>