What will happen to the VPS if the memory runs out?

Question

System administration

Comrades! Tell me what will happen to the VPS if the operation ends. The condition is the absence of a swap file.
For example, a lot of visitors have come in, everyone is crawling around the site, the web server keeps connections, but there is not enough memory.

Answer 1

oom-killer will work and kill any of the processes, freeing some memory.

Answer 2

VPS can be upgraded - add RAM as needed.