From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Robert Haas <robertmhaas@gmail.com>, vignesh C <vignesh21@gmail.com>,
        Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>,
        Craig Ringer <craig.ringer@enterprisedb.com>,
        Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Printing backtrace of postgres processes
In-reply-to: <20210506191406.hwafwkr4gs2vougq@alap3.anarazel.de>
References: 
 <CALDaNm1ig4dKFW1658YBH9338Oysc-MT6-YzeKU-ojv87MhhMQ@mail.gmail.com>
 <20210127170958.vzo33jzmqwhmn7z6@alap3.anarazel.de>
 <CALDaNm1uWKn8KGD0q8HqCPhxSUDKWCEW55aidOiJwd+vfaB+gg@mail.gmail.com>
 <CALj2ACXfXefmdUWiF0twoYEfgJ6Xk4saXctoYyzXtzkjizCdBw@mail.gmail.com>
 <CALDaNm0aEUNLZeiDAXvPsgm4nFUjUhtfeztGofmVJU--irSD8Q@mail.gmail.com>
 <CALj2ACXybys_tzWeatb9htVTuxKp29VErc6iJQYJBbdBZXv2fg@mail.gmail.com>
 <CALj2ACUhgagr-nLcte2+61khpO6uxvERvZA28hQpxtTzbz3U2g@mail.gmail.com>
 <CALDaNm3HHMxUpYYbUFM3=RYBYZjQGgnULxdDrqwaH=DovuYMSQ@mail.gmail.com>
 <3886673.1612337426@sss.pgh.pa.us>
 <CA+Tgmoa9jsOD3h3KmkZLTSpZy-oDazZqesKFquCiDBb6mQvppg@mail.gmail.com>
 <20210506191406.hwafwkr4gs2vougq@alap3.anarazel.de>
Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Thu, 06 May 2021 12:14:06 -0700"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <4175341.1620328922.1@sss.pgh.pa.us>
Date: Thu, 06 May 2021 15:22:02 -0400
Message-ID: <4175342.1620328922@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/4175342.1620328922%40sss.pgh.pa.us>
Precedence: bulk

Andres Freund <andres@anarazel.de> writes:
> On 2021-05-06 14:38:51 -0400, Robert Haas wrote:
>> On Wed, Feb 3, 2021 at 2:30 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> This point is entirely separate from the question of whether
>>> triggering stack traces at inopportune moments could cause system
>>> malfunctions, but that question is also not to be ignored.

> I think that ship kind of has sailed with
>
> commit 71a8a4f6e36547bb060dbcc961ea9b57420f7190
> Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
> Date:   2019-11-08 15:44:20 -0300
>     Add backtrace support for error reporting

The fact that we have a scarily large surface area for that to
cause problems is not a great argument for making the surface
area even larger.  Also, I don't think v13 has been out long
enough for us to have full confidence that the backtrace behavior
doesn't cause any problems already.

> we allow generating backtraces in all kind of places, including
> e.g. some inside critical sections via backtrace_functions.

If there's an elog call inside a critical section, that seems
like a problem already.  Are you sure that there are any such?

			regards, tom lane