MySQL service crashes

Question

MySQL

Good for all!
I got under my "guardianship" VPS with an online store on board. We moved to the server just the other day from a regular hosting (they stopped getting into tariffs).
I have no experience in administering servers at all, so expect a ton of stupid questions.
The problem is the following: when scanning the site through http://host-tracker.com/ru/ , the MySQL service stops on our server, the site starts trumpeting about a database connection error. I start MySQL again - the site works fine until the next scan.
Where to dig? What logs to watch?

Looking through all the files in a row, even remotely resembling logs, I came across such warnings:
1. mysql_ping() - warning that the command is missing some arguments (by the way, host-tracker.com appears in the refferer)
2. Warning that the wordfence plugin (antivirus + firewall) did not have enough memory and he went into denial. Disconnected - no effect.

The server runs on CentOS + Apache + related services. ISP Manager as a panel. The site is powered by Wordpress.

Answer 1

The problem was partially solved by disabling InnoDB in my.conf. Now MySQL does not crash.
But Host-tracker.com still gives HTTP 500 when it analyzes the server from almost anywhere.

Answer 2

Some strange description of the problem. Maybe start with mysql logs, syslog? And if there is little information, set the logging level to DEBUG for the database?

Answer 3

The site does not crash, only the MySQL server crashes. You can't connect to it after that - it just turns off. Like "service mysqld stop". Number of connections - now let's see.
.

Answer 4

Usually the muscle logs are in /var/log/mysql but where exactly they are is written in /etc/mysql/my.conf