Re: pg_stat_replication.*_lag sometimes shows NULL during active replication - Mailing list pgsql-hackers

From Fujii Masao
Subject Re: pg_stat_replication.*_lag sometimes shows NULL during active replication
Date
Msg-id CAHGQGwFzg9J_z71kwnjXOxaoO3upMW8RdT4ieE8MBLq6h-ojZg@mail.gmail.com
Whole thread
In response to Re: pg_stat_replication.*_lag sometimes shows NULL during active replication  (Shinya Kato <shinya11.kato@gmail.com>)
Responses Re: pg_stat_replication.*_lag sometimes shows NULL during active replication
List pgsql-hackers
On Mon, Mar 16, 2026 at 9:26 AM Shinya Kato <shinya11.kato@gmail.com> wrote:
> Thank you for the v4 patch. I think this approach is better than mine.
> I tested the patch and confirmed that the issue no longer reproduces
> with physical replication. However, with logical replication, the lag
> columns in pg_stat_replication still show NULL periodically at
> wal_receiver_status_interval, since send_feedback() in worker.c can
> still send duplicate positions.

I was thinking that if a feedback message triggered by
wal_receiver_status_interval has the same LSNs as the previous message,
it's expected for the lag columns to become NULL. But you see it differently,
don't you? Sorry, I failed to understand your point...

Regards,

--
Fujii Masao



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