Re: more descriptive message for process termination due to max_slot_wal_keep_size

On Fri, Dec 24, 2021 at 1:42 PM Kyotaro Horiguchi
<horikyota.ntt@gmail.com> wrote:
>
> At Thu, 23 Dec 2021 18:08:08 +0530, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> wrote in
> > On Wed, Dec 15, 2021 at 9:42 AM Kyotaro Horiguchi
> > <horikyota.ntt@gmail.com> wrote:
> > > > LOG:  invalidating slot "s1"
> > > > DETAIL:  The slot's restart_lsn 0/10000D68 is behind the limit 0/11000000 defined by max_slot_wal_keep_size.
> > >
> > > The second line could be changed like the following or anything other.
> > >
> > > > DETAIL:  The slot's restart_lsn 0/10000D68 got behind the limit 0/11000000 determined by
max_slot_wal_keep_size.
> > > .....
> > >
> >
> > The second version looks better as it gives more details. I am fine
> > with either of the above wordings.
> >
> > I would prefer everything in the same message though since
> > "invalidating slot ..." is too short a LOG message. Not everybody
> > enabled details always.
>
> Mmm. Right. I have gone too much to the same way with the
> process-termination message.
>
> I rearranged the meesages as follows in the attached version. (at master)

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?

Regards,

--
Masahiko Sawada
EDB:  https://www.enterprisedb.com/