Description:
MySQL crashed with the stack trace below:
2019-11-22T12:26:55.759278Z 8748327 [Note] Start binlog_dump to master_thread_id(8748327) slave_server(10027034), pos(, 4)
12:27:30 UTC - mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
Attempting to collect some information that could help diagnose the problem.
As this is a crash and something is definitely wrong, the information
collection process might fail.
Please help us make Percona Server better by reporting any
bugs at https://bugs.percona.com/
12:57:00 - UTC - all buried jobs in daemons where successfully unburied
key_buffer_size=8388608
read_buffer_size=131072
max_used_connections=852
max_threads=3001
thread_count=563
connection_count=563
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1202862 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.
Thread pointer: 0x7f16b0271410
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 = 7f1639d30e80 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x2c)[0x56004f56dc5c]
/usr/sbin/mysqld(handle_fatal_signal+0x489)[0x56004f3a4d89]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x110e0)[0x7f1cc8acc0e0]
/usr/sbin/mysqld(_Z20sync_mutex_to_string10latch_id_tRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x162)[0x56004f777b52]
/usr/sbin/mysqld(+0xf4b600)[0x56004f76c600]
/usr/sbin/mysqld(_Z16sync_array_printP8_IO_FILE+0xed)[0x56004f76ce2d]
/usr/sbin/mysqld(_Z10sync_printP8_IO_FILE+0x19)[0x56004f777799]
/usr/sbin/mysqld(_Z25srv_printf_innodb_monitorP8_IO_FILEmPmS1_+0x1d4)[0x56004f753cb4]
/usr/sbin/mysqld(+0xdfed12)[0x56004f61fd12]
/usr/sbin/mysqld(_Z14ha_show_statusP3THDP10handlerton12ha_stat_type+0x368)[0x56004ee7a788]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THDb+0x1822)[0x56004f2c65a2]
/usr/sbin/mysqld(_Z11mysql_parseP3THDP12Parser_stateb+0x435)[0x56004f2cc9a5]
/usr/sbin/mysqld(_Z16dispatch_commandP3THDPK8COM_DATA19enum_server_command+0x1034)[0x56004f2cdad4]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x1b7)[0x56004f2cf097]
/usr/sbin/mysqld(handle_connection+0x2a8)[0x56004f38bb68]
/usr/sbin/mysqld(pfs_spawn_thread+0x1b4)[0x56004f588374]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x74a4)[0x7f1cc8ac24a4]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7f1cc67e5d0f]
Trying to get some variables.
---------
It seems that the lack of protection of created variable:
---------
std::string sync_mutex_to_string(latch_id_t id, const std::string &created) {
std::ostringstream msg;
msg << "Mutex " << sync_latch_get_name(id) << " "
<< "created " << created;
return (msg.str());
}
---------
the created variable is passed by reference, but then that reference is de-referenced by some other thread, and by the time this function reads it, it's gone and hence causes the SIGSEGV (signal 11).
How to repeat:
I was not able to reproduce in a planned way. Waiting to see if I can get the core dumps when happens again.
Suggested fix:
Create a mutex to protect this variable. Despite the lack of a test case, it seems reasonable that this variable should be protected.
