From: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Subject: Re: logical replication launcher crash on buildfarm
To: Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org,
 Petr Jelinek <petr@2ndquadrant.com>, Peter Eisentraut <peter_e@gmx.net>
References: <20170316032833.2zxfnqe3sl3ktrbt@alap3.anarazel.de>
 <20170316034246.3uurliezczmka6cn@alap3.anarazel.de>
Message-ID: <e56bda7f-9d29-6900-0f90-96be8219b930@2ndquadrant.com>
Date: Thu, 16 Mar 2017 09:40:48 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.7.0
MIME-Version: 1.0
In-Reply-To: <20170316034246.3uurliezczmka6cn@alap3.anarazel.de>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

On 16/03/17 04:42, Andres Freund wrote:
> On 2017-03-15 20:28:33 -0700, Andres Freund wrote:
>> Hi,
>>
>> I just unstuck a bunch of my buildfarm animals.  That triggered some
>> spurious failures (on piculet, calliphoridae, mylodon), but also one
>> that doesn't really look like that:
>> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=culicidae&dt=2017-03-16%2002%3A40%3A03
>>
>> with the pertinent point being:
>>
>> ================== stack trace: pgsql.build/src/test/regress/tmp_check/data/core ==================
>> [New LWP 1894]
>> [Thread debugging using libthread_db enabled]
>> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
>> Core was generated by `postgres: bgworker: logical replication launcher                '.
>> Program terminated with signal SIGSEGV, Segmentation fault.
>> #0  0x000055e265bff5e3 in ?? ()
>> #0  0x000055e265bff5e3 in ?? ()
>> #1  0x000055d3ccabed0d in StartBackgroundWorker () at /home/andres/build/buildfarm-culicidae/HEAD/pgsql.build/../pgsql/src/backend/postmaster/bgworker.c:792
>> #2  0x000055d3ccacf4fc in SubPostmasterMain (argc=3, argv=0x55d3cdbb71c0) at /home/andres/build/buildfarm-culicidae/HEAD/pgsql.build/../pgsql/src/backend/postmaster/postmaster.c:4878
>> #3  0x000055d3cca443ea in main (argc=3, argv=0x55d3cdbb71c0) at /home/andres/build/buildfarm-culicidae/HEAD/pgsql.build/../pgsql/src/backend/main/main.c:205
>>
>> it's possible that me killing things and upgrading caused this, but
>> given this is a backend running EXEC_BACKEND, I'm a bit suspicous that
>> it's more than that.  The machine is a bit backed up at the moment, so
>> it'll probably be a while till it's at that animal/branch again,
>> otherwise I'd not have mentioned this.
> 
> For some reason it ran again pretty soon. And I'm afraid it's indeed an
> issue:
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=culicidae&dt=2017-03-16%2003%3A30%3A02
> 

Hmm, I tried with EXEC_BACKEND (and with --disable-spinlocks) and it
seems to work fine on my two machines. I don't see anything else
different on culicidae though. Sadly the backtrace is not that
informative either. I'll try to investigate more but it will take time...

-- 
  Petr Jelinek                  http://www.2ndQuadrant.com/
  PostgreSQL Development, 24x7 Support, Training & Services


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers