Server console becomes unresponsive

The problem:

The Server console became unresponsive. I could not do anything via the server console and had to kill the server via `kill -9 <pid>` as `kill <pid>` did not kill the server. While the lag was most likely caused by the lava cast (picture below), it should not make the server console unresponsive that you cannot stop it via the console.

What I expected:

I expected that despite the server lagging, I could still stop it normally and interact with the server console or atleast execute `kill <pid>` instead of `kill -9 <pid>`.

I don't know if it is relevant to this particular issue, but the lava cast did cause a server crash a few hours before (crash log below).