Mysql under DOS attack?

Question

MySQL

I want to protect the VPS, at least from minor DOS attacks, but the trouble is literally from the very first second of a single-threaded DOS attack, the mysql server crashes, despite the fact that Apache resists to the last and I never managed to fill it up even from several computers. It seems to me that this is not normal, the VPS has the following parameters: 1 core, 512 RAM, 20Gb SSD.
For reference: there is a licensed ISPManager.

Answer 1

DDOS protection, 512RAM, apache. These words cannot be used in the same sentence

Answer 2

RAM, by modern standards, is not enough of course. MySQL should be configured under it. You can take ready-made my.conf from Bitrix Environment, it is normally configured for small amounts of memory, using InnoDB

Answer 3

Most likely, apache is eating up all the memory, so mysql has no choice but to "fall".
It would be interesting to see what kind of error mysql crashes with, and start from that.