Re: speed up a logical replica setup

On Mon, Apr 29, 2024 at 5:23 PM Euler Taveira <euler@eulerto.com> wrote:
>
> On Mon, Apr 29, 2024, at 6:56 AM, Amit Kapila wrote:
>
> On Wed, Mar 27, 2024 at 1:47 AM Euler Taveira <euler@eulerto.com> wrote:
> >
> > On Tue, Mar 26, 2024, at 4:12 PM, Tomas Vondra wrote:
> >
> > Perhaps I'm missing something, but why is NUM_CONN_ATTEMPTS even needed?
> > Why isn't recovery_timeout enough to decide if wait_for_end_recovery()
> > waited long enough?
> >
> >
> > It was an attempt to decoupled a connection failure (that keeps streaming the
> > WAL) from recovery timeout. The NUM_CONN_ATTEMPTS guarantees that if the primary
> > is gone during the standby recovery process, there is a way to bail out.
> >
>
> I think we don't need to check primary if the WAL corresponding to
> consistent_lsn is already present on the standby. Shouldn't we first
> check that? Once we ensure that the required WAL is copied, just
> checking server_is_in_recovery() should be sufficient. I feel that
> will be a direct way of ensuring what is required rather than
> indirectly verifying the same (by checking pg_stat_wal_receiver) as we
> are doing currently.
>
>
> How would you check it? WAL file? During recovery, you are not allowed to use
> pg_current_wal_lsn.
>

How about pg_last_wal_receive_lsn()?

--
With Regards,
Amit Kapila.