Re: pg_basebackup --wal-method=fetch

On Thu, Feb 8, 2024 at 5:21 PM Stephen Frost <sfrost(at)snowman(dot)net> wrote:

> Greetings,
>
> * Ron Johnson (ronljohnsonjr(at)gmail(dot)com) wrote:
>
> > The word "streaming".
> > Should be "But isn't streaming the whole purpose of pg_basebackup"?
>
> I'm a bit confused on this point still as if the whole purpose of
> pg_basebackup is to be streaming ... then we should be defaulting to
> fetch mode still?
>

No. Since I thought streaming is the whole purpose of pg_basebackup, I
questioned the utility of every other method *except*
--wal-method=streaming.

> > I use PgBackRest, though, and can't imagine single-threading any
> > reasonably-sized database. In fact, one of the tasks on my mental TODO
> > list is to research how to use PgBackRest to initialize a replica
> instance
> > prior to starting Streaming Replication.
>
> [snip]

> In terms of using pgbackrest to initialize a replica ... that's
> basically running 'pgbackrest restore --type=standby'? There's really
> not much more to it than that. pgbackrest will set up the restored
> system to replay from the WAL in the archive, you'd just need to
> configure primary_conninfo so that the replica will attempt to connect
> to the primary once it's caught up with all of the WAL in the archive.
>

I haven't examined it closely enough. What little looking that I did made
me wonder whether PgBackRest handled all the replication itself, or whether
it just initialized everything and then let physical replication using
replication slots take over.