Re: ReplicationSlotRelease() crashes when the instance is in the single user mode

On Thu, Feb 20, 2025 at 4:26 PM Zhijie Hou (Fujitsu)
<houzj(dot)fnst(at)fujitsu(dot)com> wrote:
>
> On Thursday, February 20, 2025 10:23 AM Hayato Kuroda (Fujitsu) <kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
> >
> > Dear Michael,
> >
> > > I did not check how these call behave individually, just a few
> > > comments while putting my eyes on the patch.
> > >
> > > + if (!IsUnderPostmaster)
> > > + elog(ERROR,
> > > + "slot operation is prohibited in the single user
> > mode");
> > >
> > > elog() should not be used for failures that can be user-facing as this
> > > would not provide any translation.
> >
> > I intentionally used elog() because I thought single user mode is not
> > user-facing.
> > But it is OK for me to use ereport() instead.
> >
> > > I'd suggest rewording the error message to provide some more context,
> > > as well, say:
> > > "cannot use %s in single-user mode", "function_name"
> >
> > Fixed. PSA new version
>
> I'm curious about the scope of the restrictions we plan to add. For example,
> the current patch does not include checks in the functions used for consuming
> changes (such as pg_logical_slot_get_changes). Was this omission intentional?
>

Also, what about pg_replication_origin_* APIs? Do we want to restrict
those as well if we are restricting slot operations? I don't see any
solid theory presented in this thread on why we should add new checks
in multiple APIs restricting those in single-user mode.

--
With Regards,
Amit Kapila.