Re: Synchronizing slots from primary to standby

On Mon, Nov 20, 2023 at 3:17 PM Drouvot, Bertrand
<bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
>
> On 11/18/23 11:45 AM, Amit Kapila wrote:
> > On Fri, Nov 17, 2023 at 5:18 PM Drouvot, Bertrand
> > <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> >>
> >> On 11/17/23 2:46 AM, Zhijie Hou (Fujitsu) wrote:
> >>> On Tuesday, November 14, 2023 10:27 PM Drouvot, Bertrand <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> >>>
> >>> I feel the WaitForWALToBecomeAvailable may not be the best place to shutdown
> >>> slotsync worker and drop slots. There could be other reasons(other than
> >>> promotion) as mentioned in comments in case XLOG_FROM_STREAM to reach the code
> >>> there. I thought if the intention is to stop slotsync workers on promotion,
> >>> maybe FinishWalRecovery() is a better place to do it as it's indicating the end
> >>> of recovery and XLogShutdownWalRcv is also called in it.
> >>
> >> I can see that slotsync_drop_initiated_slots() has been moved in FinishWalRecovery()
> >> in v35. That looks ok.
> >>>
> >
> > I was thinking what if we just ignore creating such slots (which
> > require init state) in the first place? I think that can be
> > time-consuming in some cases but it will reduce the complexity and we
> > can always improve such cases later if we really encounter them in the
> > real world. I am not very sure that added complexity is worth
> > addressing this particular case, so I would like to know your and
> > others' opinions.
> >
>
> I'm not sure I understand your point. Are you saying that we should not create
> slots on the standby that are "currently" reported in a 'i' state? (so just keep
> the 'r' and 'n' states?)
>

Yes.

--
With Regards,
Amit Kapila.