Hello @Paul2708
I remember these sort of messages on our JupyterHub deployment at my previous job. Which variant of proxy are you using: CHP or Traefik? In our case, I remember this behaviour after few months of uninterrupted running of JupyterHub and JupyterHub proxy services. CHP has a known memory leak issue and I also noticed couple of times that CHP has too many open file descriptors due to unclosed sockets.
Event loop unresponsive means it is “blocked” by some function call. In a regular scenario it can be a blocking function that does some heavy computation work. However, that wont be the case for JupyterHub as there no “compute intensive” tasks here. I assume the blocking is caused by some socket stuff here.
I recommend you to look into memory usage and open file descriptors of JupyterHub and CHP when this problem occurs next time!!