Switched to mysql 8 and everything was stuck, the reason?

Question

MySQL

The server config did not change, before the transfer, the CPU took about a quarter. The mysql config was taken from the previous server.
Bala ubuntu 8 is now centos 7. The server has only mysql (base) and phpmyadmin, the server is the second in the whole configuration. Before After After visiting the site

has not changed, the database has not changed in size.

Answer 1

The problem is solved, one of the tables that is very loaded is changed to the memory type