Re: postgres crash on concurrent update of inheritance partitioned table

On Tue, Jan 28, 2020 at 05:17:14PM +0100, Oleksii Kliukin wrote:
>Hello there,
>
>We have experienced a few crashes a day since upgrading to pg 12.1 last
>week, during the process of updating an inheritance-partitioned table by
>several concurrent sessions.
>
>Here’s the reproducer that consistency crashes pg 12.1 (and master) on my
>machine.
>
>Setup:
>
>create table p(flag boolean);
>create table c1() inherits(p);
>create table c2() inherits(p);
>insert into c1 select false from generate_series(1,10);
>insert into c2 select false from generate_series(1,10);
>
>session 1:					session 2:
>begin;						begin
>update p set flag = true;						
>							update p set flag = true;
>commit;						server closed the connection unexpectedly
>								This probably means the server terminated abnormally
>								before or while processing the request.
>							The connection to the server was lost. Attempting reset: Failed.
>

Yeah, I can reproduce it too. If I had to guess, I'd say it's another
bug due to 

     commit 3fb307bc4a76815f96fec28a0d1525ab3fbbcfb4
     Author: Andres Freund <andres@anarazel.de>
     Date:   Mon Sep 9 05:21:30 2019 -0700

     Reorder EPQ work, to fix rowmark related bugs and improve efficiency.

which introduced relsubs_done et al, and perhaps did not get the life
cycle / resetting right. Not sure.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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