Re: Create a standby server

> On Monday, March 11th, 2024 at 3:43 PM, Stephen Frost <sfrost@snowman.net> wrote:

> Greetings,
>
> * normandavis1990 (normandavis1990@proton.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
ama 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
Standbyservers, 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