Dask worker seem die but cannot find the worker log to figure out why
Worker logs are usually managed by whatever system you use to set up Dask.  
Perhaps you used something like Kubernetes or Yarn or SLURM?  
These systems all have ways to get logs back.  
Unfortunately, once a Dask worker is no longer running, Dask itself has no ability to collect logs for you.  You need to use the system that you use to launch Dask.
I have a piece of DASK code run on local machine which work 90% of time but will stuck sometimes.  Stuck mean.  No crash, no error print out not cpu usage.  never end.    
I google and think it maybe due to some worker dead.  I will be very useful if I can see the worker log and figure out why.
But I cannot find my worker log.  I go to edit config.yaml to add loging but still see nothing from stderr. 
Then I go to dashboard --> info --> logs and see blank page.
The code it stuck is 
X_test = df_test.to_dask_array(lengths=True)
or 
proba = y_pred_proba_train[:, 1].compute()
and my ~/.config/dask/config.yaml or ~.dask/config.yaml look like
logging:
  distributed: info
  distributed.client: warning
  distributed.worker: debug
  bokeh: error 
I am using 
python 3.6
dask 1.1.4 
All I need is a way to see the log so that I can try to figure out what goes wrong.
Thanks
Joseph