mysql 运行过程中异常重启，errlog 显示mysql got signal 11 错误，已排除内存、硬盘等资源满导致重启，其他相关信息如下

数据库版本：5.6.49

操作系统版本： RHEL7.4 

内存 ：64G

buffer size : 20G

错误日志：

02:27:50 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. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail.

key_buffer_size=33554432

read_buffer_size=16777216

max_used_connections=551 

max_threads=1000 

thread_count=133

connection_count=133 

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 32813572 K bytes of memory 

Hope that's ok; if not, decrease some variables in the equation. 

Thread pointer: 0x0 

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 = 0 thread_stack 0x80000 

/mysql/bin/mysqld(my_print_stacktrace+0x35)[0x926bf5] 

/mysql/bin/mysqld(handle_fatal_signal+0x494)[0x6b04c4] 

/lib64/libpthread.so.0(+0xf5e0)[0x7fbb19ebd5e0] 

/mysql/bin/mysqld[0x9b1521]

/mysql/bin/mysqld[0xa441fe] 

/mysql/bin/mysqld[0xa5f612] 

/mysql/bin/mysqld[0xa5aaad]

/mysql/bin/mysqld[0xa5b0f7] 

/mysql/bin/mysqld[0xa5b51e] 

/lib64/libpthread.so.0(+0x7e25)[0x7fbb19eb5e25

] /lib64/libc.so.6(clone+0x6d)[0x7fbb1897234d] 

The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash.