# Signal 11 happened when I use 'SET PERSIST ONLY character ~' **URL:** \ **Category:** Percona Server for MySQL 8.0\ **Created:** [December 21, 2023, 4:57am UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289 "2023-12-21T04:57:27Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![DongyeongKim](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/dongyeongkim/32/13577_2.png) [@DongyeongKim](https://forums.percona.com/u/DongyeongKim)\ **Post date:** [December 21, 2023, 4:57am UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/1 "2023-12-21T04:57:27Z")
During the set persist only syntax execution, the DB is terminated with Signal 11 error as shown below. What is the problem with that bug? ```bash #!/bin/bash mysql -uawx -p -e "SET PERSIST_ONLY character_set_client = 'utf8mb3'" sleep 10 mysql -uawx -p -e "SET PERSIST_ONLY character_set_connection = 'utf8mb3'" sleep 10 mysql -uawx -p -e "SET PERSIST_ONLY character_set_client = 'utf8mb4'" mysql -uawx -p -e "SET PERSIST_ONLY character_set_connection = 'utf8mb4'" ``` ```bash 2023-12-21T04:51:46Z UTC - mysqld got signal 11 ; Most likely, you have hit a bug, but this error can also be caused by malfunctioning hardware. BuildID[sha1]=72ec6f0cba041274a205d4d298600c482628efa2 Server Version: 8.0.34-26 Percona Server (GPL), Release 26, Revision 0fe62c85 Thread pointer: 0x7fbf3c042110 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 7fbf402f0c10 thread_stack 0x100000 /usr/sbin/mysqld(my_print_stacktrace(unsigned char const*, unsigned long)+0x41) [0x21944d1] /usr/sbin/mysqld(print_fatal_signal(int)+0x2c2) [0x121b3b2] /usr/sbin/mysqld(handle_fatal_signal+0xd5) [0x121b595] /lib64/libpthread.so.0(+0x12ce0) [0x7fc00544fce0] /usr/sbin/mysqld() [0x119adc4] /usr/sbin/mysqld() [0xf8fe24] /usr/sbin/mysqld(std::_Function_handler(THD*, std::function, Suppress_not_found_error, Force_sensitive_system_variable_access, Is_already_locked, Is_single_thread) const::{lambda(System_variable_tracker const&, sys_var*)#1}>::_M_invoke(std::_Any_data const&, System_variable_tracker const&, sys_var*&&)+0x39) [0xe15019] /usr/sbin/mysqld(System_variable_tracker::access_system_variable(THD*, std::function, Suppress_not_found_error, Force_sensitive_system_variable_access, Is_already_locked, Is_single_thread) const+0x95) [0xfbf6f5] /usr/sbin/mysqld(std::optional System_variable_tracker::access_system_variable(THD*, std::function, Suppress_not_found_error, Force_sensitive_system_variable_access, Is_already_locked, Is_single_thread) const+0x12d) [0xf809ad] /usr/sbin/mysqld(Persisted_variables_cache::set_variable(THD*, set_var*)+0xa1) [0xf80b41] /usr/sbin/mysqld(sql_set_variables(THD*, List*, bool)+0x130) [0xfbd3b0] /usr/sbin/mysqld(mysql_execute_command(THD*, bool)+0x24f7) [0x10944e7] /usr/sbin/mysqld(dispatch_sql_command(THD*, Parser_state*, bool)+0x5cb) [0x109670b] /usr/sbin/mysqld(dispatch_command(THD*, COM_DATA const*, enum_server_command)+0x2487) [0x10991b7] /usr/sbin/mysqld(do_command(THD*)+0x1d6) [0x1099d46] /usr/sbin/mysqld() [0x120b178] /usr/sbin/mysqld() [0x262d2b4] /lib64/libpthread.so.0(+0x81cf) [0x7fc0054451cf] /lib64/libc.so.6(clone+0x43) [0x7fc0037ead83] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (7fbf3c0336c0): SET PERSIST_ONLY character_set_connection = 'utf8mb3' Connection ID (thread ID): 9 Status: NOT_KILLED Please help us make Percona Server better by reporting any bugs at https://bugs.percona.com/ You may download the Percona Server operations manual by visiting http://www.percona.com/software/percona-server/. You may find information in the manual which will help you identify the cause of the crash. ``` And the value does not normally enter mysqld-auto.cnf. ```bash cat mysqld-auto.cnf {"Version": 2, "mysql_dynamic_variables": {"character_set_client": {"Value": "", "Metadata": {"Host": "localhost", "User": "root", "Timestamp": 1703134901191749}}, "character_set_connection": {"Value": "", "Metadata": {"Host": "localhost", "User": "awx", "Timestamp": 1703134814346602}}}} ``` ---
**Author:** ![yves.trudeau](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/yves.trudeau/32/2825_2.png) [@yves.trudeau](https://forums.percona.com/u/yves.trudeau)\ **Post date:** [December 21, 2023, 4:56pm UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/2 "2023-12-21T16:56:20Z")
This is obviously a bug, easy to reproduce in my test env. I did found a workaround though, almost by accident: ```auto chgrp mysql /etc/mysql chmod 775 /etc/mysql ``` No clue exactly why this is needed since the mysqld-auto.cnf file is not stored there. I’ll try to find the issue in the code. ---
**Author:** ![yves.trudeau](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/yves.trudeau/32/2825_2.png) [@yves.trudeau](https://forums.percona.com/u/yves.trudeau)\ **Post date:** [December 21, 2023, 5:41pm UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/3 "2023-12-21T17:41:11Z")
Well, no so sure about the workaround, I am unable to revert it. At the same time, some is strange with the persisted variables, you (and I) have: ```auto "Value": "" ``` I tried twice to set: ```auto mysql> SET PERSIST_ONLY character_set_filesystem = "latin1"; ERROR 2013 (HY000): Lost connection to MySQL server during query ... mysql> SET PERSIST_ONLY character_set_filesystem = "latin1"; No connection. Trying to reconnect... Connection id: 8 Current database: ***NONE*** Query OK, 0 rows affected (0,01 sec) ``` It worked the 2nd without any change, just waited a bit for mysql to restart. However: ```auto { "Version": 2, "mysql_dynamic_variables": { "log_slow_verbosity": { "Value": "microtime,query_plan,innodb", "Metadata": { "Host": "localhost", "User": "root", "Timestamp": 1703180007162173 } }, "character_set_client": { "Value": "", "Metadata": { "Host": "localhost", "User": "root", "Timestamp": 1703179011200801 } }, "character_set_filesystem": { "Value": "", "Metadata": { "Host": "localhost", "User": "root", "Timestamp": 1703180162252645 } } ``` Why are the Value fields empty? Could well be related. ---
**Author:** ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)\ **Post date:** [December 21, 2023, 5:56pm UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/4 "2023-12-21T17:56:56Z")
@DongyeongKim Please open a bug report at [https://jira.percona.com/](https://jira.percona.com/) with your example script and the output. I reproduced it as well. I will submit confirmation when I see your bug. ---
**Author:** ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)\ **Post date:** [December 21, 2023, 5:59pm UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/5 "2023-12-21T17:59:07Z")
Seems to be an issue with PERSIST\_ONLY: ```auto $ ./use -e "SET PERSIST_ONLY character_set_client = 'utf8mb4'" $ cat data/mysqld-auto.cnf {"Version": 2, "mysql_dynamic_variables": {"character_set_client": {"Value": "", "Metadata": {"Host": "localhost", "User": "msandbox", "Timestamp": 1703181465104374}}}} $ rm data/mysqld-auto.cnf $ ./use -e "SET PERSIST character_set_client = 'utf8mb4'" $ cat data/mysqld-auto.cnf {"Version": 2, "mysql_dynamic_variables": {"character_set_client": {"Value": "utf8mb4", "Metadata": {"Host": "localhost", "User": "msandbox", "Timestamp": 1703181481544031}}}} ``` @DongyeongKim I changed your script to PERSIST and it worked fine. Still a bug though for PERSIST\_ONLY ---
**Author:** ![jinyou.ma](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/jinyou.ma/32/19714_2.png) [@jinyou.ma](https://forums.percona.com/u/jinyou.ma)\ **Post date:** [July 25, 2025, 6:26am UTC](https://forums.percona.com/t/signal-11-happened-when-i-use-set-persist-only-character/27289/6 "2025-07-25T06:26:13Z")
I have reported the bug at [Jira](https://perconadev.atlassian.net/browse/PS-10099)