Named servers are deleted when culled by the idle culler

[tylergraff]

Context

In order for named servers to be shut down by the idle culler, the --no-force-alive flag must be provided in the server command. However, when this is done and the idle culler does shut down a named server, that server appears to not only be shut down, but also completely deleted from the JupyterHub home screen.

I would expect that the idle culler would only shut down the server from running, not delete it entirely from the home page.

Repro Steps:

1.) Create an example named server using the custom command http.server {port} --no-force-alive. The --no-force-alive flag is necessary to repro this issue; it ensures the jupyterhub idle culler will eventually cull the server when it is inactive.

2.) Observe a link to the named server you just created in the JupyterHub home screen

3.) Start the server if it is not started already, and allow it to remain idle (no web traffic/requests to it)

4.) Wait for the idle culler to shut the server down. The amount of time this takes depends on the default idle culler configuration used (likely on the order of an hour).

5.) After the idle culler has shut down the server, observe that the link to the server is no longer on the JupyterHub home page.

Value and/or benefit

This bug affects the usability of named servers. If a named server is configured to be shut down by the idle culler when it has been idle, it will not only be shut down but also completely deleted.

Anything else?

No response