Re: pgbench: allow to exit immediately when any client is aborted

On Mon, 7 Aug 2023 11:02:48 +0900
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp> wrote:

> On Sat, 05 Aug 2023 12:16:11 +0900 (JST)
> Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp> wrote:
>
> > > Hi,
> > >
> > > I would like to propose to add an option to pgbench so that benchmark
> > > can quit immediately when any client is aborted. Currently, when a
> > > client is aborted due to some error, for example, network trouble,
> > > other clients continue their run until a certain number of transactions
> > > specified -t is reached or the time specified by -T is expired. At the
> > > end, the results are printed, but they are not useful, as the message
> > > "Run was aborted; the above results are incomplete" shows.
> >
> > Sounds like a good idea. It's a waste of resources waiting for
> > unusable benchmark results until t/T expired. If we graze on the
> > screen, then it's easy to cancel the pgbench run. But I frequently let
> > pgbench run without sitting in front of the screen especially when t/T
> > is large (it's recommended that running pgbench with large enough t/T
> > to get usable results).
>
> Thank you for your agreement.
>
> > > For precise benchmark purpose, we would not want to wait to get such
> > > incomplete results, rather we would like to know some trouble happened
> > > to allow a quick retry. Therefore, it would be nice to add an option to
> > > make pgbench exit instead of continuing run in other clients when any
> > > client is aborted. I think adding the optional is better than whole
> > > behavioural change because some users that use pgbench just in order
> > > to stress on backends for testing purpose rather than benchmark might
> > > not want to stop pgbench even a client is aborted.
> > >
> > > Attached is the patch to add the option --exit-on-abort.
> > > If this option is specified, when any client is aborted, pgbench
> > > immediately quit by calling exit(2).

I attached v2 patch including the documentation and some comments
in the code.

Regards,
Yugo Nagata

> > >
> > > What do you think about it?
> >
> > I think aborting pgbench by calling exit(2) is enough. It's not worth
> > the trouble to add more codes for this purpose.
>
> In order to stop pgbench more gracefully, it might be better to make
> each thread exit at more proper timing after some cleaning-up like
> connection close. However, pgbench code doesn't provide such functions
> for inter-threads communication. If we would try to make this, both
> pthread and Windows versions would be needed. I don't think it is necessary
> to make such effort for --exit-on-abort option, as you said.
>
> Regards,
> Yugo Nagata
>
> >
> > Best reagards,
> > --
> > Tatsuo Ishii
> > SRA OSS LLC
> > English: http://www.sraoss.co.jp/index_en/
> > Japanese:http://www.sraoss.co.jp
>
>
> --
> Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>
>
>

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