core dump

coredump.txt

https://ngelinux.com/how-to-enable-core-dump-collection-in-linux-for-every-user/#:~:text=%20Enabling%20Core%20dump%20in%20Linux.%20%201,core%20unlimited%E2%80%9D%20to%20enable%20the%20core...%20More%20

postgres@db:~/playground/logical_replication$ ulimit -a
core file size          (blocks, -c) 0

as root
printf "* soft core unlimited\n" >> /etc/security/limits.conf
postgres@db:~/playground/logical_replication$ sudo vim /etc/security/limits.conf

postgres@db:~/playground/logical_replication$ ulimit -c
0
postgres@db:~/playground/logical_replication$ ulimit -c 102400
postgres@db:~/playground/logical_replication$ ulimit -c
102400

where to dump to
postgres@db:~/playground/logical_replication$ sudo sysctl -w kernel.core_pattern=/var/crash/core.%u.%e.%p
kernel.core_pattern = /var/crash/core.%u.%e.%p
postgres@db:~/playground/logical_replication$ sudo cat /proc/sys/kernel/core_pattern
/var/crash/core.%u.%e.%p
postgres@db:~/playground/logical_replication$ pg_ctl -D example start
waiting for server to start....2021-06-28 12:26:08.784 IST [1548] LOG:  00000: starting PostgreSQL 14beta1 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, 64-bit
2021-06-28 12:26:08.784 IST [1548] LOCATION:  PostmasterMain, postmaster.c:1128
2021-06-28 12:26:08.784 IST [1548] LOG:  00000: listening on IPv4 address "127.0.0.1", port 5432
2021-06-28 12:26:08.784 IST [1548] LOCATION:  StreamServerPort, pqcomm.c:582
2021-06-28 12:26:08.790 IST [1548] LOG:  00000: listening on Unix socket "/tmp/.s.PGSQL.5432"
2021-06-28 12:26:08.790 IST [1548] LOCATION:  StreamServerPort, pqcomm.c:577
2021-06-28 12:26:08.800 IST [1549] LOG:  00000: database system was shut down at 2021-06-27 21:32:14 IST
2021-06-28 12:26:08.800 IST [1549] LOCATION:  StartupXLOG, xlog.c:6492
2021-06-28 12:26:08.818 IST [1548] LOG:  00000: database system is ready to accept connections
2021-06-28 12:26:08.818 IST [1548] LOCATION:  reaper, postmaster.c:3042
 done
server started

postgres@db:~/playground/logical_replication$ kill -ABRT 1548
postgres@db:~/playground/logical_replication$ sudo ls /var/crash/
core.1000.postgres.1548




################################# then sample gdb run
root@db:~# gdb /home/postgres/pgsql/bin/postgres /var/crash/core.1000.postgres.1548
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2
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Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
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<http://www.gnu.org/software/gdb/bugs/>.
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Reading symbols from /home/postgres/pgsql/bin/postgres...
[New LWP 1548]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/home/postgres/pgsql/bin/postgres -D example'.
Program terminated with signal SIGABRT, Aborted.
#0  0x00007fe17fa370da in __GI___select (nfds=nfds@entry=7, readfds=readfds@entry=0x7fff7fb8d3f0, writefds=writefds@entry=0x0,
    exceptfds=exceptfds@entry=0x0, timeout=timeout@entry=0x7fff7fb8d340) at ../sysdeps/unix/sysv/linux/select.c:41
41      ../sysdeps/unix/sysv/linux/select.c: No such file or directory.
(gdb) bt
#0  0x00007fe17fa370da in __GI___select (nfds=nfds@entry=7, readfds=readfds@entry=0x7fff7fb8d3f0, writefds=writefds@entry=0x0,
    exceptfds=exceptfds@entry=0x0, timeout=timeout@entry=0x7fff7fb8d340) at ../sysdeps/unix/sysv/linux/select.c:41
#1  0x000055acbd55776c in ServerLoop () at postmaster.c:1709
#2  0x000055acbd5590bf in PostmasterMain (argc=<optimized out>, argv=0x55acbf11ef30) at postmaster.c:1417
#3  0x000055acbd2eecd2 in main (argc=3, argv=0x55acbf11ef30) at main.c:209