Mysql se plante inopinément

InnoDB: Warning: a long semaphore wait: 
--Thread 140616820184832 has waited at row0ins.cc line 2338 for 241.00 seconds the semaphore: 
X-lock (wait_ex) on RW-latch at 0x7fe4bf71d740 created in file buf0buf.cc line 1069 
a writer (thread id 140616820184832) has reserved it in mode  wait exclusive 
number of readers 1, waiters flag 0, lock_word: ffffffffffffffff 
Last time read locked in file buf0flu.cc line 1056 
Last time write locked in file /build/mysql-5.6-dqP7lI/mysql-5.6-5.6.30/storage/innobase/btr/btr0sea.cc line 931 
InnoDB: Warning: a long semaphore wait: 
--Thread 140616820987648 has waited at trx0sys.ic line 103 for 241.00 seconds the semaphore: 
X-lock (wait_ex) on RW-latch at 0x7fe4bf6419c0 created in file buf0buf.cc line 1069 
a writer (thread id 140616820987648) has reserved it in mode  wait exclusive 
number of readers 1, waiters flag 1, lock_word: ffffffffffffffff 
Last time read locked in file buf0flu.cc line 1056 
Last time write locked in file /build/mysql-5.6-dqP7lI/mysql-5.6-5.6.30/storage/innobase/include/trx0sys.ic line 103 
...... 
===================================== 
2018-05-02 16:22:23 7fe3eab6b700 INNODB MONITOR OUTPUT 
===================================== 
..... 
OS WAIT ARRAY INFO: reservation count 2825 
--Thread 140616820184832 has waited at row0ins.cc line 2338 for 259.00 seconds the semaphore: 
X-lock (wait_ex) on RW-latch at 0x7fe4bf71d740 created in file buf0buf.cc line 1069 
a writer (thread id 140616820184832) has reserved it in mode  wait exclusive 
number of readers 1, waiters flag 0, lock_word: ffffffffffffffff 
Last time read locked in file buf0flu.cc line 1056 
Last time write locked in file /build/mysql-5.6-dqP7lI/mysql-5.6-5.6.30/storage/innobase/btr/btr0sea.cc line 931 
--Thread 140616820987648 has waited at trx0sys.ic line 103 for 259.00 seconds the semaphore: 
X-lock (wait_ex) on RW-latch at 0x7fe4bf6419c0 created in file buf0buf.cc line 1069 
a writer (thread id 140616820987648) has reserved it in mode  wait exclusive 
number of readers 1, waiters flag 1, lock_word: ffffffffffffffff 
Last time read locked in file buf0flu.cc line 1056 
Last time write locked in file /build/mysql-5.6-dqP7lI/mysql-5.6-5.6.30/storage/innobase/include/trx0sys.ic line 103 
.... 
---TRANSACTION 453618943, not started 
mysql tables in use 3, locked 0 
MySQL thread id 18313, OS thread handle 0x7fe3e5cc0700, query id 223424 localhost 127.0.0.1 ossec preparing 
..... 
-------- 
FILE I/O 
-------- 
I/O thread 0 state: waiting for completed aio requests (insert buffer thread) 
I/O thread 1 state: waiting for completed aio requests (log thread) 
I/O thread 2 state: waiting for completed aio requests (read thread) 
I/O thread 3 state: waiting for completed aio requests (read thread) 
I/O thread 4 state: waiting for completed aio requests (write thread) 
...... 
2018-05-02 19:40:33 4690 [ERROR] InnoDB: Failed to find tablespace for table '"snorby"."delayed_jobs"' in the cache. Attempting to load the tablespace with space id 6766. 
2018-05-02 19:40:33 4690 [ERROR] InnoDB: Failed to find tablespace for table '"snorby"."tcphdr"' in the cache. Attempting to load the tablespace with space id 6787. 
...... 
2018-05-02 19:40:33 4690 [Note] Recovering after a crash using /var/log/mysql/mysql-bin 
2018-05-02 19:40:34 4690 [Note] Starting crash recovery... 
2018-05-02 19:40:34 4690 [Note] Crash recovery finished. 
17:40:34 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=524288 
read_buffer_size=2097152 
max_used_connections=0 
max_threads=32 
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 = 131992 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 0x30000 
/usr/sbin/mysqld(my_print_stacktrace+0x3b)[0x90742b] 
/usr/sbin/mysqld(handle_fatal_signal+0x36a)[0x666f1a] 
/lib/x86_64-linux-gnu/libpthread.so.0(+0x110c0)[0x7fef467060c0] 
/usr/sbin/mysqld(_ZN9MYSQL_LOG17generate_new_nameEPcPKc+0x74)[0x64eab4] 
/usr/sbin/mysqld(_ZN9MYSQL_LOG26init_and_set_log_file_nameEPKcS1_13enum_log_type10cache_type+0x3f)[0x64eb5f] 
/usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG11open_binlogEPKcS1_10cache_typembbbP28Format_description_log_event+0x72)[0x8a6a82] 
/usr/sbin/mysqld(_Z11mysqld_mainiPPc+0xc87)[0x5981c7] 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1)[0x7fef450772e1] 
/usr/sbin/mysqld[0x58c34a] 
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. 
180502 19:40:34 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended