[pgpool-general: 8036] Re: PgPool-II 4.2.7: several segfaults on CentOS 8

Tatsuo Ishii ishii at sraoss.co.jp
Thu Mar 3 08:51:43 JST 2022


Not sure at this moment because the cause of the segfault is not known
yet. Also it's not known how to reproduce the segfault. So I think
more investigation is needed.

> Thanks!
> In the meantime, do you think that upgrading to 4.3 could solve the problem?
> 
> Thank you
> 
> Il giorno mer 2 mar 2022 alle ore 14:51 Tatsuo Ishii <ishii at sraoss.co.jp>
> ha scritto:
> 
>> Ok, It seems the segfault occured in watchdog.
>>
>> Usama,
>> Can you please take a look at this?
>>
>> Best reagards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese:http://www.sraoss.co.jp
>>
>> From: shacky <shacky83 at gmail.com>
>> Subject: Re: [pgpool-general: 8031] Re: PgPool-II 4.2.7: several segfaults
>> on CentOS 8
>> Date: Wed, 2 Mar 2022 12:57:50 +0100
>> Message-ID: <CAPz3gm=
>> wPi_FqSJpnN99gKFBtg0Lg-0x7RiqAPdytfqra8saYQ at mail.gmail.com>
>>
>> > Here is the complete bt output:
>> >
>> ===================================================================================================
>> > DEV root at proxy2-dev ~# gdb /usr/bin/pgpool
>> >
>> /root/pgpool-coredumps/core.pgpool.26.e120553488834d47bff3c72a21a9bba1.694540.1646129274000000
>> > GNU gdb (GDB) Red Hat Enterprise Linux 8.2-16.el8
>> > Copyright (C) 2018 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".
>> > Type "show configuration" for configuration details.
>> > For bug reporting instructions, please see:
>> > <http://www.gnu.org/software/gdb/bugs/>.
>> > Find the GDB manual and other documentation resources online at:
>> >     <http://www.gnu.org/software/gdb/documentation/>.
>> >
>> > For help, type "help".
>> > Type "apropos word" to search for commands related to "word"...
>> > Reading symbols from /usr/bin/pgpool...Reading symbols from
>> > /usr/lib/debug/usr/bin/pgpool-4.2.5-1pgdg.rhel8.x86_64.debug...done.
>> > done.
>> >
>> > warning: Can't open file (null) during file-backed mapping note
>> processing
>> > [New LWP 694540]
>> > [Thread debugging using libthread_db enabled]
>> > Using host libthread_db library "/lib64/libthread_db.so.1".
>> > Core was generated by `pgpool: watchdog                                '.
>> > Program terminated with signal SIGSEGV, Segmentation fault.
>> > #0  __strlen_sse2 () at ../sysdeps/x86_64/multiarch/../strlen.S:120
>> > 120 movdqu (%rax), %xmm4
>> > (gdb) bt
>> > #0  __strlen_sse2 () at ../sysdeps/x86_64/multiarch/../strlen.S:120
>> > #1  0x00007fe9b70ac0af in _IO_vfprintf_internal (s=s at entry
>> =0x7ffdb575f7c0,
>> > format=format at entry=0x55d3177fd2a8 "STATE MACHINE INVOKED WITH EVENT =
>> %s
>> > Current State = %s",
>> >     ap=ap at entry=0x7ffdb575f9b0) at vfprintf.c:1638
>> > #2  0x00007fe9b7164bfd in ___vsnprintf_chk (s=s at entry=0x55d3177fd6b8
>> "STATE
>> > MACHINE INVOKED WITH EVENT = it has found us again", maxlen=<optimized
>> > out>, maxlen at entry=1024,
>> >     flags=flags at entry=1, slen=slen at entry=18446744073709551615,
>> > format=format at entry=0x55d3177fd2a8 "STATE MACHINE INVOKED WITH EVENT =
>> %s
>> > Current State = %s",
>> >     args=args at entry=0x7ffdb575f9b0) at vsnprintf_chk.c:63
>> > #3  0x000055d316dc9013 in vsnprintf (__ap=0x7ffdb575f9b0,
>> > __fmt=0x55d3177fd2a8 "STATE MACHINE INVOKED WITH EVENT = %s Current
>> State =
>> > %s", __n=1024,
>> >     __s=0x55d3177fd6b8 "STATE MACHINE INVOKED WITH EVENT = it has found
>> us
>> > again") at /usr/include/bits/stdio2.h:80
>> > #4  pvsnprintf (buf=0x55d3177fd6b8 "STATE MACHINE INVOKED WITH EVENT = it
>> > has found us again", len=len at entry=1024,
>> >     fmt=fmt at entry=0x55d3177fd2a8 "STATE MACHINE INVOKED WITH EVENT = %s
>> > Current State = %s", args=args at entry=0x7ffdb575f9b0) at
>> utils/psprintf.c:126
>> > #5  0x000055d316e11eab in appendStringInfoVA (str=str at entry
>> =0x7ffdb575f990,
>> > fmt=fmt at entry=0x55d3177fd2a8 "STATE MACHINE INVOKED WITH EVENT = %s
>> Current
>> > State = %s",
>> >     args=args at entry=0x7ffdb575f9b0) at stringinfo.c:138
>> > #6  0x000055d316ddeabf in errmsg (fmt=fmt at entry=0x55d316f577d0 "STATE
>> > MACHINE INVOKED WITH EVENT = %s Current State = %s") at
>> > ../../src/utils/error/elog.c:665
>> > #7  0x000055d316e30c4b in watchdog_state_machine
>> > (event=event at entry=WD_EVENT_I_AM_APPEARING_FOUND,
>> > wdNode=wdNode at entry=0x55d3177fbcf8, pkt=pkt at entry=0x0,
>> >     clusterCommand=clusterCommand at entry=0x0) at watchdog.c:5394
>> > #8  0x000055d316e34a7b in cluster_service_message_processor
>> > (pkt=0x55d317804898, wdNode=0x55d3177fbcf8) at watchdog.c:4030
>> > #9  standard_packet_processor (wdNode=wdNode at entry=0x55d3177fbcf8,
>> > pkt=pkt at entry=0x55d317804898) at watchdog.c:4202
>> > #10 0x000055d316e312cd in watchdog_state_machine_nw_isolation
>> > (clusterCommand=<optimized out>, pkt=<optimized out>, wdNode=<optimized
>> > out>, event=<optimized out>)
>> >     at watchdog.c:6458
>> > #11 watchdog_state_machine (event=event at entry=WD_EVENT_PACKET_RCV,
>> > wdNode=wdNode at entry=0x55d3177fbcf8, pkt=pkt at entry=0x55d317804898,
>> > clusterCommand=clusterCommand at entry=0x0)
>> >     at watchdog.c:5561
>> > #12 0x000055d316e38514 in read_sockets (rmask=rmask at entry
>> =0x7ffdb57604e0,
>> > pending_fds_count=pending_fds_count at entry=1) at watchdog.c:8207
>> > #13 0x000055d316e3b04f in watchdog_main () at watchdog.c:3500
>> > #14 0x000055d316e3bb81 in fork_watchdog_child () at watchdog.c:1127
>> > #15 initialize_watchdog () at watchdog.c:625
>> > #16 0x000055d316d73088 in reaper () at main/pgpool_main.c:2428
>> > #17 0x000055d316d79e28 in PgpoolMain (discard_status=<optimized out>,
>> > clear_memcache_oidmaps=<optimized out>) at main/pgpool_main.c:473
>> > #18 0x000055d316d7053c in main (argc=<optimized out>,
>> argv=0x7ffdb576d1b8)
>> > at main/main.c:365
>> >
>> ===================================================================================================
>> >
>> > Thank you!
>> >
>> > Il giorno mer 2 mar 2022 alle ore 05:05 Tatsuo Ishii <ishii at sraoss.co.jp
>> >
>> > ha scritto:
>> >
>> >> Can you please share the result of gdb command "bt"?  Otherwise we
>> >> cannot figure out which place of pgpool is related to the problem.
>> >> --
>> >> Tatsuo Ishii
>> >> SRA OSS, Inc. Japan
>> >> English: http://www.sraoss.co.jp/index_en.php
>> >> Japanese:http://www.sraoss.co.jp
>> >>
>> >> > This is the coredump of the segmentation fault happened on proxy2-dev:
>> >> >
>> >> >
>> >>
>> ===================================================================================================
>> >> > DEV root at proxy2-dev /v/l/s/coredump# gdb /usr/bin/pgpool
>> >> >
>> >>
>> /root/pgpool-coredumps/core.pgpool.26.e120553488834d47bff3c72a21a9bba1.694540.1646129274000000
>> >> > GNU gdb (GDB) Red Hat Enterprise Linux 8.2-16.el8
>> >> > Copyright (C) 2018 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".
>> >> > Type "show configuration" for configuration details.
>> >> > For bug reporting instructions, please see:
>> >> > <http://www.gnu.org/software/gdb/bugs/>.
>> >> > Find the GDB manual and other documentation resources online at:
>> >> >     <http://www.gnu.org/software/gdb/documentation/>.
>> >> >
>> >> > For help, type "help".
>> >> > Type "apropos word" to search for commands related to "word"...
>> >> > Reading symbols from /usr/bin/pgpool...Reading symbols from
>> >> > /usr/lib/debug/usr/bin/pgpool-4.2.5-1pgdg.rhel8.x86_64.debug...done.
>> >> > done.
>> >> >
>> >> > warning: Can't open file (null) during file-backed mapping note
>> >> processing
>> >> > [New LWP 694540]
>> >> > [Thread debugging using libthread_db enabled]
>> >> > Using host libthread_db library "/lib64/libthread_db.so.1".
>> >> > Core was generated by `pgpool: watchdog
>>   '.
>> >> > Program terminated with signal SIGSEGV, Segmentation fault.
>> >> > #0  __strlen_sse2 () at ../sysdeps/x86_64/multiarch/../strlen.S:120
>> >> > 120 movdqu (%rax), %xmm4
>> >> >
>> >>
>> ===================================================================================================
>> >> >
>> >> > Thanks.
>> >> >
>> >> > Il giorno mar 1 mar 2022 alle ore 17:39 shacky <shacky83 at gmail.com>
>> ha
>> >> > scritto:
>> >> >
>> >> >> Hi,
>> >> >> I am experiencing many segfaults on PgPool-II 4.2.7 installed on two
>> >> >> different environments (production and test).
>> >> >>
>> >> >> Each environment is composed by three different PgPool-II nodes
>> >> configured
>> >> >> in a PgPool-II watchdog cluster, and I am experiencing segfaults on
>> >> every 6
>> >> >> PgPool-II nodes.
>> >> >>
>> >> >> The 6 PgPool-II nodes are distributed on 4 different physical
>> servers,
>> >> so
>> >> >> it's very unlikely that it's due to some hardware problems.
>> >> >>
>> >> >> These are the snippets of the segfaults notifications:
>> >> >>
>> >> >>
>> >>
>> ===================================================================================================
>> >> >> DEV root at proxy1-dev ~# dmesg|grep pgpool
>> >> >> [   15.970081] pgpool[834]: segfault at 8 ip 00007fb6069f5d8a sp
>> >> >> 00007fff848e7448 error 4 in libc-2.28.so[7fb60695c000+1bc000]
>> >> >> [   17.672642] pgpool[1336]: segfault at 8 ip 00007fb6069f5d8a sp
>> >> >> 00007fff848e73e8 error 4 in libc-2.28.so[7fb60695c000+1bc000]
>> >> >>
>> >> >> DEV root at proxy2-dev ~# dmesg|grep pgpool
>> >> >> [ 2109.530239] pgpool[848]: segfault at 8 ip 00007f372d024d8a sp
>> >> >> 00007ffe5126c7d8 error 4 in libc-2.28.so[7f372cf8b000+1bc000]
>> >> >> [ 4752.698303] pgpool[22406]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f298 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >> [ 4761.219745] pgpool[22450]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f238 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >> [7089616.463274] pgpool[22568]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f208 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >> [7090394.285732] pgpool[661708]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f208 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >> [7090504.438435] pgpool[661929]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f208 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >> [7090528.565248] pgpool[661991]: segfault at 8 ip 00007fe9b70f3d8a sp
>> >> >> 00007ffdb575f238 error 4 in libc-2.28.so[7fe9b705a000+1bc000]
>> >> >>
>> >> >> DEV root at proxy3-dev ~# dmesg|grep pgpool
>> >> >> [ 2085.795853] pgpool[879]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6678 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7088526.747095] pgpool[20105]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d65e8 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7088528.639860] pgpool[946407]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089324.627060] pgpool[946415]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089384.787587] pgpool[946506]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089580.047313] pgpool[946521]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089591.340077] pgpool[946547]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089597.788270] pgpool[946556]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7089614.064323] pgpool[946565]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7090492.104936] pgpool[946574]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d65e8 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >> [7090575.965820] pgpool[946743]: segfault at 8 ip 00007f9f45e57d8a sp
>> >> >> 00007ffc605d6618 error 4 in libc-2.28.so[7f9f45dbe000+1bc000]
>> >> >>
>> >> >> PROD root at proxy1-prod ~# dmesg|grep pgpool
>> >> >> [    6.631205] pgpool[814]: segfault at 8 ip 00007fe9729dbd8a sp
>> >> >> 00007ffe7174ae88 error 4 in libc-2.28.so[7fe972942000+1bc000]
>> >> >> [   17.054962] pgpool[1288]: segfault at 8 ip 00007fe9729dbd8a sp
>> >> >> 00007ffe7174ae28 error 4 in libc-2.28.so[7fe972942000+1bc000]
>> >> >> [868124.710835] pgpool[1415]: segfault at 8 ip 00007fe9729dbd8a sp
>> >> >> 00007ffe7174ae28 error 4 in libc-2.28.so[7fe972942000+1bc000]
>> >> >> [868127.082112] pgpool[1632535]: segfault at 8 ip 00007fe9729dbd8a sp
>> >> >> 00007ffe7174ae28 error 4 in libc-2.28.so[7fe972942000+1bc000]
>> >> >>
>> >> >> PROD root at proxy2-prod ~# dmesg|grep pgpool
>> >> >> [   16.783629] pgpool[835]: segfault at 8 ip 00007f5f87877d8a sp
>> >> >> 00007ffe3d47eb08 error 4 in libc-2.28.so[7f5f877de000+1bc000]
>> >> >> [   21.012660] pgpool[1381]: segfault at 8 ip 00007f5f87877d8a sp
>> >> >> 00007ffe3d47eaa8 error 4 in libc-2.28.so[7f5f877de000+1bc000]
>> >> >> [ 1978.102123] pgpool[1400]: segfault at 8 ip 00007f5f87877d8a sp
>> >> >> 00007ffe3d47eaa8 error 4 in libc-2.28.so[7f5f877de000+1bc000]
>> >> >>
>> >> >> PROD root at proxy3-prod ~# dmesg|grep pgpool
>> >> >> [   13.567572] pgpool[826]: segfault at 8 ip 00007f4359c84d8a sp
>> >> >> 00007fff04ddf008 error 4 in libc-2.28.so[7f4359beb000+1bc000]
>> >> >> [   15.559884] pgpool[1384]: segfault at 8 ip 00007f4359c84d8a sp
>> >> >> 00007fff04ddefa8 error 4 in libc-2.28.so[7f4359beb000+1bc000]
>> >> >> [1094174.197742] pgpool[1398]: segfault at 8 ip 00007f4359c84d8a sp
>> >> >> 00007fff04ddef78 error 4 in libc-2.28.so[7f4359beb000+1bc000]
>> >> >>
>> >> >>
>> >>
>> ===================================================================================================
>> >> >>
>> >> >> The operating system is CentOS 8 (fully updated) with these PgPool-II
>> >> >> packages installed:
>> >> >>
>> >> >>
>> >>
>> ===================================================================================================
>> >> >> PROD root at proxy3 ~# rpm -qa|grep -i pgpool
>> >> >> pgpool-II-pg12-4.2.7-1pgdg.rhel8.x86_64
>> >> >> pgpool-II-release-4.2-1.noarch
>> >> >>
>> >> >>
>> >>
>> ===================================================================================================
>> >> >>
>> >> >> Could you help me to understand what's going on, please?
>> >> >>
>> >> >> Thank you very much!
>> >> >> Bye
>> >> >>
>> >>
>>


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