Re: client_connection_check_interval default value

Hi,

Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, 13 Mar 2026 Cum, 13:36 tarihinde
şunu yazdı:
>
> On Tue, Mar 10, 2026 at 10:42 AM Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> wrote:
> >
> >
> >
> > > On Mar 9, 2026, at 22:12, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> > >
> > > On Mon, Mar 9, 2026 at 6:03 PM Hüseyin Demir <huseyin(dot)d3r(at)gmail(dot)com> wrote:
> > >>
> > >> Hi Fujii,
> > >>
> > >> Thanks for the patch. The rate-limiting approach makes sense to me. A couple of thoughts:
> > >>
> > >> 1) I think Chao Li's suggestion of using max(10s, deadlock_timeout) as the rate limit interval is worth adopting. If someone has set deadlock_timeout to, say, 30s or 60s, they've already signaled they don't need frequent lock-wait feedback. Logging every 10s after a 60s deadlock_timeout feels inconsistent with that intent.
> > >
> > > Or perhaps they expect the log message to be emitted only once,
> > > just after deadlock_timeout, similar to the current behavior when
> > > client_connection_check_interval is not set, I guess.
> > >
> > > I'm now starting thinking it might be better to preserve the existing
> > > behavior (emitting the message once per wait) regardless of whether
> > > client_connection_check_interval is set, and implement that first.
> > >
> > > If there is a need to emit the message periodically, we could add that
> > > as a separate feature later so that it works independently of
> > > the client_connection_check_interval setting.
> > >
> > > Thought?
> >
> > Yeah, IMHO, preserving the existing behavior is preferable. Logically, client_connection_check_interval and log_lock_waitsbelong to two different departments. Even though they cross paths at the implementation level today, having the behavior of log_lock_waits change just because client_connection_check_interval is adjusted seems surprising.
>
> So, attached is a patch that ensures the "still waiting on lock" message is
> reported at most once during a lock wait, even if the wait is interrupted.
>

The new v2 patch looks good to me.

One open question from my side is should we include a test for this
behaviour ? Because we mentioned adding a different GUC in the future
to manage this rate-limiting approach. It can be useful in the future
once we consider/re-visit this approach. If the tests and other future
ideas can be developed later together we can consider adding tests
later.

Thanks for the patch again!

Regards.