The server + mysql constantly reboots. What is the problem? Little RAM?

Question

MySQL

Lately I've been noticing a problem with the server...
The load seems to be holding normally -= 16 GB of RAM memory.
But I don’t understand why - but it often happens that the server reboots (I noticed from the vest panel that mysql is rebooted first of all, apparently the problem is in it).
The graph shows how the graph jumps. Tell me, what's the problem here?
I noticed a connection (possibly - in the fact that when the load on the processor reaches 100% for a long time (30 seconds) - then the site is cut off.
+ There was also a setting on the OPcache hosting (sort of) - and perhaps because of this such problems ..

Tell me what it could be? The schedule is attached. Here



is another schedule for the week:

Answer 1

I would look at the MySQL logs first. It would also be necessary to identify what creates such a load. Perhaps some heavy queries without indexes, etc. You can enable logging of slow queries, and then analyze them using EXPLAIN - create indexes, if necessary.

Answer 2

I have a suspicion that the hosting problem is connected either with some limits on the duration of work when CPU / IOPS are overloaded), or maybe the server is simply overheating and it is rebooting.
It is also possible blocking in the program (PHP) or the web server as a result of the slow operation of the DBMS.
In order to be able to find out, it is necessary to analyze the logs of the OS, web server, Mysql and monitor the use of resources at problematic intervals.
Technical information for a precise answer is not provided.

Answer 3

Run mysqltuner.pl