Re: client_connection_check_interval default value - Mailing list pgsql-hackers

From Fujii Masao
Subject Re: client_connection_check_interval default value
Date
Msg-id CAHGQGwEBvWXU4sdu2DMxaUWdPYQvGesr1VPyX-WnSxtW9nN6UA@mail.gmail.com
Whole thread
In response to Re: client_connection_check_interval default value  (Chao Li <li.evan.chao@gmail.com>)
Responses Re: client_connection_check_interval default value
Re: client_connection_check_interval default value
List pgsql-hackers
On Tue, Mar 10, 2026 at 10:42 AM Chao Li <li.evan.chao@gmail.com> wrote:
>
>
>
> > On Mar 9, 2026, at 22:12, Fujii Masao <masao.fujii@gmail.com> wrote:
> >
> > On Mon, Mar 9, 2026 at 6:03 PM Hüseyin Demir <huseyin.d3r@gmail.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.
Ifsomeone 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_waitsbelongto two different departments. Even though they cross paths at the implementation level today,
havingthe 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.

Regards,

--
Fujii Masao

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