David Sutherland

> Which versions of Jupyter Hub & Server were you using? Is there a version where this isn't the case? ``` jupyter-client==7.3.1 jupyter-server==1.21.0 jupyter-telemetry==0.1.0 jupyter_core==4.11.2 jupyterhub==3.0.0 jupyterlab-pygments==0.2.2 ```

> I'm not sure how the server responds to this, might need some extra logic to get it to call the shutdown logic. This logic also shuts down terminals, kernels,...

Yeah, bit odd, Scheduler and UIS stores are fine:  So the last delta arriving and/or applied to the UIS must be `running` .. and when I refresh the page...

Here's the problem delta arriving at the WUI: 

It's already been added, but we received an extra added workflow delta... I suspect the UIS is constructing this..

Thing is.. that delta isn't consistently sent, so it makes me think it's from the UIS scan or something..

Finding it really hard to replicate the issue.. the content of the delta says two things: - It looks like the contact info in the `added` which suggests that the...

The issue is more easily reproduced with higher scan rate (lower scan_interval), which is a clue in itself.. slowly narrowing in on it.

I believe I've figured out what's going on here.. Two things really. At the UIS, occasionally the UIS connects to the Scheduler before the first start-up delta arrives from the...

Thanks for looking at this @datamel ! Oh that's handy to know, found the hub created one.. a whole pile of them (~600 or so) We should use it, it...