Date: Mon, 26 Aug 2019 22:23:25 +0200
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Paquier <michael@paquier.xyz>,
	Andres Freund <andres@anarazel.de>,
	Thomas Munro <thomas.munro@enterprisedb.com>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: subscriptionCheck failures on nightjar
Message-ID: <20190826202325.soqe6gmgnenbmzee@development>
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On Mon, Aug 26, 2019 at 11:01:20AM -0400, Tom Lane wrote:
>Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>> I'm willing to take a stab at it, but to do that I need a way to
>> reproduce it. Tom, you mentioned you've managed to reproduce it in a
>> qemu instance, but that it took some fiddling with qemu parmeters or
>> something. Can you share what exactly was necessary?
>
>I don't recall exactly what I did anymore, and it was pretty fiddly
>anyway.  Upthread I suggested
>
>>> Now that we know where the problem is, you could probably make it highly
>>> reproducible by inserting a sleep of a few msec between the rename and the
>>> second fsync.
>
>so why not try that first?
>

Ah, right. I'll give that a try.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services