Re: Fix around conn_duration in pgbench - Mailing list pgsql-hackers

From Yugo NAGATA
Subject Re: Fix around conn_duration in pgbench
Date
Msg-id 20210730144343.87b622db5d78a9a0e33a58b9@sraoss.co.jp
Whole thread Raw
In response to Re: Fix around conn_duration in pgbench  (Fujii Masao <masao.fujii@oss.nttdata.com>)
Responses Re: Fix around conn_duration in pgbench
List pgsql-hackers
Hello Fujii-san,

On Fri, 30 Jul 2021 02:01:08 +0900
Fujii Masao <masao.fujii@oss.nttdata.com> wrote:

> 
> 
> On 2021/07/29 2:23, Fujii Masao wrote:
> > 
> > 
> > On 2021/07/28 16:15, Yugo NAGATA wrote:
> >>> I found another disconnect_all().
> >>>
> >>>     /* XXX should this be connection time? */
> >>>     disconnect_all(state, nclients);
> >>>
> >>> The measurement is also not necessary here.
> >>> So the above comment should be removed or updated?
> >>
> >> I think this disconnect_all will be a no-op because all connections should
> >> be already closed in threadRun(), but I left it just to be sure that
> >> connections are all cleaned-up. I updated the comment for explaining above.
> >>
> >> I attached the updated patch. Could you please look at this?
> > 
> > Thanks for updating the patch! LGTM.
> 
> This patch needs to be back-patched because it fixes the bug
> in measurement of disconnection delays. Thought?

This patch fixes three issues of connection time measurement:

1. The initial connection time is measured and stored into conn_duration
   but the result is never used.
2. The disconnection time are not measured even when -C is specified.
3. The disconnection time measurement at the end of threadRun() is
   not necessary.

The first one exists only in v14 and master, but others are also in v13 and
before. So, I think we can back-patch these fixes.

> But the patch fails to be back-patched to v13 or before because
> pgbench's time logic was changed by commit 547f04e734.
> Do you have the patches that can be back-patched to v13 or before?

I attached the patch for v13.

Regards,
Yugo Nagata

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

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