Re: Improve pg_sync_replication_slots() to wait for primary to advance

On Thu, Oct 9, 2025 at 2:14 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Tue, Oct 7, 2025 at 5:13 PM shveta malik <shveta(dot)malik(at)gmail(dot)com> wrote:
> >
> > On Tue, Oct 7, 2025 at 4:49 PM Ashutosh Bapat
> > <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
> > >
> > > Shorter nap times mean higher possibility of wasted CPU cycles - that
> > > should be avoided. Doing that for a test's sake seems wrong. Is there
> > > a way that the naptime can controlled by external factors such as
> > > likelihood of an advanced slot (just firing bullets in the dark) or is
> > > the naptime controllable by user interface like GUC? The test can use
> > > those interfaces.
> > >
> >
> > Yes, we can control naptime based on the fact whether any slots are
> > being advanced on primary. This is how a slotsync worker does. It
> > keeps on doubling the naptime if there is no activity on primary
> > starting from 200ms till max of 30 sec. As soon as activity happens,
> > naptime is reduced to 200ms again.
> >
>
> Is there a reason why we don't want to use the same naptime strategy
> for API and worker?
>

There was a suggestion at [1] for a shorter naptime in case of API.

[1]: https://www.postgresql.org/message-id/CAExHW5sQLJGhEA%2B9ZFVwZUpqfFFP5KPn9w64t3uiHSuiEH-9mQ%40mail.gmail.com

thanks
Shveta