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Subject: Re: BUG #16036: Segmentation fault while doing an update
From: =?utf-8?B?0JDQvdGC0L7QvSDQktC70LDRgdC+0LI=?= <druidvav@gmail.com>
In-Reply-To: <C2DA3A10-8D6F-4EC0-9A24-58F5480FCF85@gmail.com>
Date: Fri, 4 Oct 2019 04:26:25 +0300
Cc: pgsql-bugs@lists.postgresql.org,
 PG Bug reporting form <noreply@postgresql.org>
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Message-Id: <4EA4A542-4C02-4684-B269-FC9254C60028@gmail.com>
References: <16036-28184c90d952fb7f@postgresql.org>
 <4E1FB33C-7280-487B-B3D1-D3C247AA9E3D@anarazel.de>
 <FBA5344D-9356-49BA-9B47-C3705C2E9481@gmail.com>
 <A1695349-530C-4871-AED5-0262A9BC9920@anarazel.de>
 <C2DA3A10-8D6F-4EC0-9A24-58F5480FCF85@gmail.com>
To: Andres Freund <andres@anarazel.de>
Precedence: bulk

Tried only two concurrent queries and crash is still present, so it=E2=80=99=
s not about total query count.

> 4 =D0=BE=D0=BA=D1=82. 2019 =D0=B3., =D0=B2 4:24, =D0=90=D0=BD=D1=82=D0=BE=
=D0=BD =D0=92=D0=BB=D0=B0=D1=81=D0=BE=D0=B2 <druidvav@gmail.com> =
=D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB(=D0=B0):
>=20
> Hello,
>=20
> This test script always causes a crash:
>=20
> postgres@gp-app01:~$ cat test.sh
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
> psql -d gdeposylka -c "update tracking.test_session set list_position =
=3D list_position + 1 where id =3D 85638;" &
>=20
> create table tracking.test_result
> (
> 	id serial not null
> 		constraint test_result_pkey
> 			primary key,
> 	session_id integer
> 		constraint test_result_session_id_fkey
> 			references tracking.test_session,
> 	reported_at timestamp(0) default now(),
> 	courier varchar(25) not null,
> 	tracking_number varchar(60) not null,
> 	status varchar(25) not null,
> 	fail_combo integer default 0 not null,
> 	response_test text,
> 	response_real text,
> 	response_time real,
> 	code smallint,
> 	message text,
> 	retry integer
> );
>=20
> create index test_result_session_id_idx
> 	on tracking.test_result (session_id);
>=20
> Didn=E2=80=99t finish isolating bug from my database so i=E2=80=99m =
not sure if it work out for you. Single queries work as usual, only =
concurrent ones cause crash.
>=20
>=20
>> 4 =D0=BE=D0=BA=D1=82. 2019 =D0=B3., =D0=B2 4:20, Andres Freund =
<andres@anarazel.de> =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB(=D0=B0):
>>=20
>> Hi,=20
>>=20
>> On October 3, 2019 6:14:33 PM PDT, "=D0=90=D0=BD=D1=82=D0=BE=D0=BD =
=D0=92=D0=BB=D0=B0=D1=81=D0=BE=D0=B2" <druidvav@gmail.com> wrote:
>>> Hello,
>>>=20
>>> Looks like disabling jit didn=E2=80=99t affect backtrace at all:
>>>=20
>>> 0  GetMemoryChunkContext (pointer=3D0x0) at
>>> ./build/../src/include/utils/memutils.h:127
>>> #1  pfree (pointer=3D0x0) at
>>> ./build/../src/backend/utils/mmgr/mcxt.c:1033
>>> #2  0x0000555d7276aaca in heap_freetuple (htup=3D<optimized out>) at
>>> ./build/../src/backend/access/common/heaptuple.c:1340
>>> #3  0x0000555d72918889 in tts_buffer_heap_clear =
(slot=3D0x555d73dbb118)
>>> at ./build/../src/backend/executor/execTuples.c:652
>>> #4  0x0000555d72918cbe in ExecClearTuple (slot=3D0x555d73dbb118) at
>>> ./build/../src/include/executor/tuptable.h:428
>>> #5  ExecResetTupleTable (tupleTable=3D0x555d73db5a10, =
shouldFree=3Dfalse)
>>=20
>> That's good - I was only looking at that because of the truncated =
backtrace. Did you do anything to make that work better this time?
>>=20
>> Are there any details that you can provide? Schema? Any extensions in =
use?=20
>>=20
>> Does the problem happen always, or just under concurrency?
>>=20
>> Andres
>> --=20
>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>=20