Re: Fix around conn_duration in pgbench

Hello Fujii-san,

On Mon, 30 Aug 2021 23:36:30 +0900
Fujii Masao <masao.fujii@oss.nttdata.com> wrote:

> 
> 
> On 2021/08/26 12:13, Yugo NAGATA wrote:
> > Ok. That makes sense. The output reports "including connections establishing"
> > and "excluding connections establishing" regardless with -C, so we should
> > measure delays in the same way.
> 
> On second thought, it's more reasonable and less confusing not to
> measure the disconnection delays at all? Since whether the benchmark result
> should include the disconnection delays or not is not undocumented,
> probably we cannot say strongly the current behavior (i.e., the disconnection
> delays are not measured) is a bug. Also since the result has not included
> the disconnection delays so far, the proposed change might slightly change
> the benchmark numbers reported, which might confuse the users.
> ISTM that at least it's unwise to change long-stable branches for this... Thought?

Ok. I agree with you that it is better to not change the behavior of pg13 or
before at least. As for pg14 or later, I wonder that we can change it when pg14
is released because the output was already change in the commit 547f04e734,
although, I am not persisting to measure disconnection delay since the effect
to tps would be very slight. At least, if we decide to not measure disconnection
delays, I think we should fix as so, like the attached patch.

> > I updated the patch for pg13 to measure disconnection delay when -C is not
> > specified. I attached the updated patch for pg13 as well as one for pg14
> > which is same as attached before.
> 
> Thanks! I pushed the part of the patch, which gets rid of unnecessary
> measure of connection delays from pgbench.

Thank you!


Regards, Yugo Nagata

-- 
Yugo NAGATA <nagata@sraoss.co.jp>