dask-scheduler does not launch Bokeh

I am seeing this starting with distributed 1.21.8 and bokeh 1.0.1 but also with the very latest versions. Starting dask-scheduler will not start bokeh any more. We are using our own compiled Python 3.6.7 and install all packages via pip. I tested it with the latest Anaconda Python 3.7 and that works fine so it seems to be an issue with our Python install …

petersen@koshuf0:~$ dask-scheduler --port 12121 --bokeh-port 12122 --host $SLURMD_NODENAME --pid-file dask-scheduler.pid
distributed.scheduler - INFO - -----------------------------------------------
distributed.scheduler - INFO - Clear task state
distributed.scheduler - INFO -   Scheduler at:  tcp://172.30.1.100:12121
distributed.scheduler - INFO - Local Directory: /loc/scratch/27074823/scheduler-xu5904ps
distributed.scheduler - INFO - -----------------------------------------------
Connection to koshu-login closed by remote host.

below Scheduler at: I should be seeing

distributed.scheduler - INFO -       bokeh at:      172.30.1.100:12122

but it is not there and bokeh is not started, there are no errors in the log. I would be grateful for any hint . There does not seem to be a --verbose or --debug option for dask-scheduler ?

[mrocklin]

Everything is fine. If you want the dashboard (which is useful) then you’ll have to install the additional library bokeh for visualization

pip install bokeh

or

conda install bokeh

[blazespinnaker]

I was getting this error - " Web dashboard not loaded. Unable to import bokeh". It’s not clear from reading the documentation on how to get more information on what’s causing this. I agree with the above that dask is impaired without the web dashboard as I don’t know if or how my workers are being utilized properly. Is there a verbose logging option I’ve missed?

I was able to fix it by going python3 -m pip install “dask[complete]” again. I guess I must have ran something which clobbered a version of something.