Re: Fix around conn_duration in pgbench

From: Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>
To: Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com>
Cc: Asif Rehman <asifr(dot)rehman(at)gmail(dot)com>, pgsql-hackers(at)lists(dot)postgresql(dot)org, Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
Subject: Re: Fix around conn_duration in pgbench
Date: 2021-08-31 05:15:10
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

Hello Fujii-san,

On Mon, 30 Aug 2021 23:36:30 +0900
Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)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(at)sraoss(dot)co(dot)jp>

Attachment Content-Type Size
pgbench-not-measure-disconnect.patch text/x-diff 712 bytes

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tatsuo Ishii 2021-08-31 05:18:48 Re: Fix around conn_duration in pgbench
Previous Message Fabien COELHO 2021-08-31 05:01:58 Re: Fix around conn_duration in pgbench