Re: more descriptive message for process termination due to max_slot_wal_keep_size

Thank you for the comment.

At Fri, 24 Dec 2021 17:06:57 +0900, Masahiko Sawada <sawada.mshk@gmail.com> wrote in 
> Thank you for the patch! +1 for improving the messages.
> 
> >
> > > LOG:  terminating process %d to release replication slot \"%s\" because its restart_lsn %X/%X exceeds
max_slot_wal_keep_size
> > > DETAIL:  The slot got behind the limit %X/%X determined by max_slot_wal_keep_size.
> >
> > > LOG:  invalidating slot \"%s\" because its restart_LSN %X/%X exceeds max_slot_wal_keep_size
> > c> DETAIL:  The slot got behind the limit %X/%X determined by max_slot_wal_keep_size.
> 
> -
> LSN_FORMAT_ARGS(restart_lsn))));
> +
> LSN_FORMAT_ARGS(restart_lsn)),
> +                                                errdetail("The slot
> got behind the limit %X/%X determined by max_slot_wal_keep_size.",
> +
> LSN_FORMAT_ARGS(oldestLSN))));
> 
> Isn't oldestLSN calculated not only by max_slot_wal_keep_size but also
> by wal_keep_size?

Right. But I believe the two are not assumed to be used at once. One
can set wal_keep_size larger than max_slot_wal_keep_size but it is
actually a kind of ill setting.

LOG:  terminating process %d to release replication slot \"%s\" because its restart_lsn %X/%X exceeds
max_slot_wal_keep_size
DETAIL:  The slot got behind the limit %X/%X determined by max_slot_wal_keep_size and wal_keep_size.

Mmm. I don't like this.  I feel we don't need such detail in the
message..  I'd like to hear opinions from others, please.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center