how to close tensorboard server with jupyter notebook
The jupyter stuff seems fine. In general, if you don't close TensorBoard properly, you'll find out as soon as you try to turn on TensorBoard again and it fails because port 6006 is taken. If that isn't happening, then your method is fine.
As regards the logdir, passing in the top level logdir is generally best because that way you will get support for comparing multiple "runs" of the same code in TensorBoard. However, for this to work, it's important that each "run" be in its own subdirectory, e.g.:
logs/run1/..tfevents..
logs/run2/..tfevents..
tensorboard --logdir=logs
what is the proper way to close tensorboard with jupyter notebook? 
I'm coding tensorflow on my jupyter notebook.                                        To launch, I'm doing:                                                                     1.  

!tensorboard --logdir = logs/
open a new browser tab and type in localhost:6006

to close, I just do:

close the tensorflow tab on my browser
on jupyter notebook, I click on interrupt kernel 

Just wondering if this is the proper way....
BTW, in my code I set my log file as './log/log1'. 
when starting tensorboard, should I use --logdir = ./log  or --logdir = ./log/log1?   
thank you very much.