How to Release a Port Being Listened by Viser in Jupyter Without Restarting the Kernel

[JintaoLee-Roger]

Hi,

I have been using Viser in Jupyter notebooks and encountered an issue related to port management:

When I run a Viser program, it starts the server on http://0.0.0.0:8080 by default. If that port is occupied, it switches to 8081, and so on. However, when I interrupt the notebook, it seems that the original port (e.g., 8080) isn’t released properly, so running the cell again results in the use of the next available port (e.g., 8081).

Is there a way to explicitly release or close the listening state of the port (e.g., 8080) without needing to kill the entire Python kernel or restart the Jupyter environment? I am looking for a method that can programmatically clean up and release the port, ensuring that the original port can be reused in subsequent runs.

Any guidance or suggestions on how to manage port cleanup in such cases would be highly appreciated!

Thank you for your help!

[JintaoLee-Roger]

This question should be repeated, see #310

[brentyi]

To free up the port more generally there's also a ViserServer.stop() method, but it looks like this is actually broken in the recent releases. I have a fix in #313.