Try doing some rate limiting in order to not cause the dead lock. Should probably also disable write cache. And if it still doesn't work switch to a bare metal

Try doing some rate limiting in order to not cause the dead lock. Should probably also disable write cache. And if it still doesn't work switch to a bare metal machine. And give it a lot of swap and up the swappiness. Swapping is a much better alternative then crashing. VPS providers doesn't like swap because it will tear their SSD disks, so the swap and swappiness is probably preset too low.