Re: Synchronizing slots from primary to standby

On Wed, Jan 24, 2024 at 2:38 PM Bertrand Drouvot
<bertranddrouvot.pg@gmail.com> wrote:
>
> Hi,
>
> On Wed, Jan 24, 2024 at 01:51:54PM +0530, Amit Kapila wrote:
> > On Wed, Jan 24, 2024 at 11:24 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> > >
> > > On Wed, Jan 24, 2024 at 2:43 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > > >
> > > > >
> > > > > +/* GUC variable */
> > > > > +bool       enable_syncslot = false;
> > > > >
> > > > > Is enable_syncslot a really good name? We use "enable" prefix only for
> > > > > planner parameters such as enable_seqscan, and it seems to me that
> > > > > "slot" is not specific. Other candidates are:
> > > > >
> > > > > * synchronize_replication_slots = on|off
> > > > > * synchronize_failover_slots = on|off
> > > > >
> > > >
> > > > I would prefer the second one. Would it be better to just say
> > > > sync_failover_slots?
> > >
> > > Works for me. But if we want to extend this option for non-failover
> > > slots as well in the future, synchronize_replication_slots (or
> > > sync_replication_slots) seems better. We can extend it by having an
> > > enum later. For example, the values can be on, off, or failover etc.
> > >
> >
> > I see your point. Let us see if others have any suggestions on this.
>
> I also see Sawada-San's point and I'd vote for "sync_replication_slots". Then for
> the current feature I think "failover" and "on" should be the values to turn the
> feature on (assuming "on" would mean "all kind of supported slots").

Even if others agree and we change this GUC name to
"sync_replication_slots", I feel we should keep the values as "on" and
"off" currently, where "on" would mean 'sync failover slots' (docs can
state that clearly).  I do not think we should support sync of "all
kinds of supported slots" in the first version. Maybe we can think
about it for future versions.

thanks
Shveta