Re: Parallel Seq Scan

edit: maybe this is more useful? :)

(gdb) bt full
#0 0x0000000000490b56 in heap_parallelscan_nextpage ()
No symbol table info available.
#1 0x0000000000493fdf in heap_getnext ()
No symbol table info available.
#2 0x00000000005c0733 in SeqNext ()
No symbol table info available.
#3 0x00000000005ac5d9 in ExecScan ()
No symbol table info available.
#4 0x00000000005a5c08 in ExecProcNode ()
No symbol table info available.
#5 0x00000000005b5298 in ExecGather ()
No symbol table info available.
#6 0x00000000005a5aa8 in ExecProcNode ()
No symbol table info available.
#7 0x00000000005b68b9 in MultiExecHash ()
No symbol table info available.
#8 0x00000000005b7256 in ExecHashJoin ()
No symbol table info available.
#9 0x00000000005a5b18 in ExecProcNode ()
No symbol table info available.
#10 0x00000000005b0ac9 in fetch_input_tuple ()
No symbol table info available.
#11 0x00000000005b1eaf in ExecAgg ()
No symbol table info available.
#12 0x00000000005a5ad8 in ExecProcNode ()
No symbol table info available.
#13 0x00000000005c11e1 in ExecSort ()
No symbol table info available.
#14 0x00000000005a5af8 in ExecProcNode ()
No symbol table info available.
#15 0x00000000005ba164 in ExecLimit ()
No symbol table info available.
#16 0x00000000005a5a38 in ExecProcNode ()
No symbol table info available.
#17 0x00000000005a2343 in standard_ExecutorRun ()
No symbol table info available.
#18 0x000000000069cb08 in PortalRunSelect ()
No symbol table info available.
#19 0x000000000069de5f in PortalRun ()
No symbol table info available.
#20 0x000000000069bc16 in PostgresMain ()
No symbol table info available.
#21 0x0000000000466f55 in ServerLoop ()
No symbol table info available.
#22 0x0000000000648436 in PostmasterMain ()
No symbol table info available.
#23 0x00000000004679f0 in main ()
No symbol table info available.

On Tue, Nov 17, 2015 at 12:38 PM, Bert <biertie(at)gmail(dot)com> wrote:

> Hi,
>
> this is the backtrace:
> gdb /var/lib/pgsql/9.6/data/ /var/lib/pgsql/9.6/data/core.7877
> GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-64.el7
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <
> http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-redhat-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> /var/lib/pgsql/9.6/data/: Success.
> [New LWP 7877]
> Missing separate debuginfo for the main executable file
> Try: yum --enablerepo='*debug*' install
> /usr/lib/debug/.build-id/02/20b77a9ab8f607b0610082794165fccedf210d
> Core was generated by `postgres: postgres tpcds [loca'.
> Program terminated with signal 11, Segmentation fault.
> #0 0x0000000000490b56 in ?? ()
> (gdb) bt full
> #0 0x0000000000490b56 in ?? ()
> No symbol table info available.
> #1 0x0000000000003668 in ?? ()
> No symbol table info available.
> #2 0x00007f956249a008 in ?? ()
> No symbol table info available.
> #3 0x000000000228c498 in ?? ()
> No symbol table info available.
> #4 0x0000000000000001 in ?? ()
> No symbol table info available.
> #5 0x000000000228ad00 in ?? ()
> No symbol table info available.
> #6 0x0000000000493fdf in ?? ()
> No symbol table info available.
> #7 0x00000000021a8e50 in ?? ()
> No symbol table info available.
> #8 0x0000000000000000 in ?? ()
> No symbol table info available.
> (gdb) q
>
> Is there something else I can do?
>
> On Mon, Nov 16, 2015 at 8:59 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
> wrote:
>
>> On Mon, Nov 16, 2015 at 2:51 PM, Bert <biertie(at)gmail(dot)com> wrote:
>> > I've just pulled and compiled the new code.
>> > I'm running a TPC-DS like test on different PostgreSQL installations,
>> but
>> > running (max) 12queries in parallel on a server with 12cores.
>> > I've configured max_parallel_degree to 2, and I get messages that
>> backend
>> > processes crash.
>> > I am running the same test now with 6queries in parallel, and parallel
>> > degree to 2, and they seem to work. for now. :)
>> >
>> > This is the output I get in /var/log/messages
>> > Nov 16 20:40:05 woludwha02 kernel: postgres[22918]: segfault at
>> 7fa3437bf104
>> > ip 0000000000490b56 sp 00007ffdf2f083a0 error 6 in
>> postgres[400000+5b5000]
>> >
>> > Is there something else I should get?
>>
>> Can you enable core dumps e.g. by passing the -c option to pg_ctl
>> start? If you can get a core file, you can then get a backtrace
>> using:
>>
>> gdb /path/to/postgres /path/to/core
>> bt full
>> q
>>
>> That should be enough to find and fix whatever the bug is. Thanks for
>> testing.
>>
>> --
>> Robert Haas
>> EnterpriseDB: http://www.enterprisedb.com
>> The Enterprise PostgreSQL Company
>>
>
>
>
> --
> Bert Desmet
> 0477/305361
>

--
Bert Desmet
0477/305361