Re: Logging replication state changes

On Wed, Dec 29, 2021 at 2:04 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> SATYANARAYANA NARLAPURAM <satyanarlapuram(at)gmail(dot)com> writes:
> > I noticed that below critical replication state changes are DEBUG1 level
> > logged. Any concern about changing the below two messages log level to
> LOG?
>
> Why? These seem like perfectly routine messages.
>

Consider a scenario where we have a primary and two sync standby (s1 and
s2) where s1 is a preferred failover target and s2 is next with
synchronous_standby_names = 'First 1 ('s1','s2')'. In an event, s1
streaming replication is broken and reestablished because of a planned or
an unplanned event then s2 participates in the sync commits and makes sure
the writes are not stalled on the primary. I would like to know the time
window where s1 is not actively acknowledging the commits and the writes
are dependent on s2. Also if the service layer decides to failover to s2
instead of s1 because s1 is lagging I need evidence in the log to explain
the behavior.

> regards, tom lane
>