今天突然发现mysql数据库宕机了

InnoDB数据库的问题，但是无法判断是哪个库的问题。后来，根据搜到的内容，将/var/lib/mysql下面的ibdata1重命名为ibdata，问题解决。

03:59:16 UTC - mysqld got signal 6 ;

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=16777216
read_buffer_size=262144
max_used_connections=0
max_threads=151
thread_count=0
connection_count=0
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 133926 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 0x40000
/usr/local/mysql/libexec/mysqld(my_print_stacktrace+0x29) [0x934279]
/usr/local/mysql/libexec/mysqld(handle_fatal_signal+0x41a) [0x6fa65a]
/lib64/libpthread.so.0() [0x3cd320f4c0]
/lib64/libc.so.6(gsignal+0x35) [0x393ca329a5]
/lib64/libc.so.6(abort+0x175) [0x393ca34185]
/usr/local/mysql/libexec/mysqld(page_cur_search_with_match+0x735) [0x81b6a5]
/usr/local/mysql/libexec/mysqld(btr_cur_search_to_nth_level+0x683) [0x7c2473]
/usr/local/mysql/libexec/mysqld(btr_pcur_open_on_user_rec+0x62) [0x86a382]
/usr/local/mysql/libexec/mysqld() [0x7df643]
/usr/local/mysql/libexec/mysqld(dict_load_sys_table+0x58) [0x7e50b8]
/usr/local/mysql/libexec/mysqld(dict_boot+0x88f) [0x86b68f]
/usr/local/mysql/libexec/mysqld(innobase_start_or_create_for_mysql+0xfea) [0x84909a]
/usr/local/mysql/libexec/mysqld() [0x7b445a]
/usr/local/mysql/libexec/mysqld(ha_initialize_handlerton(st_plugin_int*)+0x31) [0x6eb661]
/usr/local/mysql/libexec/mysqld() [0x77497d]
/usr/local/mysql/libexec/mysqld(plugin_init(int*, char**, int)+0x720) [0x777c00]
/usr/local/mysql/libexec/mysqld() [0x602aaf]
/usr/local/mysql/libexec/mysqld(main+0x1c6) [0x606c66]
/lib64/libc.so.6(__libc_start_main+0xfd) [0x393ca1ec5d]
/usr/local/mysql/libexec/mysqld() [0x53c2a9]
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.