Date: Sat, 7 Mar 2020 22:17:09 +0100
From: Julien Rouhaud <rjuju123@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Paquier <michael@paquier.xyz>,
	pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Add an optional timeout clause to isolationtester step.
Message-ID: <20200307211709.6kfpiddif4uxafg5@nol>
References: <20200303092551.GB1890@paquier.xyz>
 <20200304051510.GE2593@paquier.xyz>
 <CAOBaU_Z=qkE42VQ25mps+zyAz+WUn3wZoev4uhGW+gAXBBS2YA@mail.gmail.com>
 <20200305035354.GQ2593@paquier.xyz>
 <20200306131547.GA2904@nol>
 <20200307014142.GC1531@paquier.xyz>
 <20200307061615.c47sju2bytuiaazv@nol>
 <8441.1583595994@sss.pgh.pa.us>
 <20200307205328.ffidfyo3me46qscn@nol>
 <15903.1583615371@sss.pgh.pa.us>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <15903.1583615371@sss.pgh.pa.us>
Precedence: bulk

On Sat, Mar 07, 2020 at 04:09:31PM -0500, Tom Lane wrote:
> Julien Rouhaud <rjuju123@gmail.com> writes:
> > On Sat, Mar 07, 2020 at 10:46:34AM -0500, Tom Lane wrote:
> >> What's the actual need that you're trying to deal with?
>
> > Testing the correct behavior of non trivial commands, such as CIC/reindex
> > concurrently, that fails during the execution.
>
> Hmm ... don't see how a timeout helps with that?

For reindex concurrently, a SELECT FOR UPDATE on a different connection can
ensure that the reindex will be stuck at some point, so canceling the command
after a long enough timeout reproduces the original faulty behavior.