Re: Fix around conn_duration in pgbench

On Tue, 31 Aug 2021 15:39:18 +0900 (JST)
Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp> wrote:

> >> >> > My 0.02€: From a benchmarking perspective, ISTM that it makes sense to
> >> >> > include disconnection times, which are clearly linked to connections,
> >> >> > especially with -C. So I'd rather have the more meaningful figure even
> >> >> > at the price of a small change in an undocumented feature.
> >> >>
> >> >> +1. The aim of -C is trying to measure connection overhead which
> >> >> naturally includes disconnection overhead.
> >> >
> >> > I think it is better to measure disconnection delays when -C is specified in
> >> > pg 14. This seems not necessary when -C is not specified because pgbench just
> >> > reports "initial connection time".
> >>
> >> Ok.
> >>
> >> > However, what about pg13 or later? Do you think we should also change the
> >> > behavior of pg13 or later? If so, should we measure disconnection delay even
> >> > when -C is not specified in pg13?
> >>
> >> You mean "pg13 or before"?
> >
> > Sorry, you are right. I mean "pg13 or before".
>
> I would think we should leave as it is for pg13 and before to not surprise users.

Ok. Thank you for your opinion. I also agree with not changing the behavior of
long-stable branches, and I think this is the same opinion as Fujii-san.

Attached is the patch to fix to measure disconnection delays that can be applied to
pg14 or later.

Regards,
Yugo Nagata

--
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>