I wanted to stop current tensorboard notebook running in google colab because I could not start another tensorboard server. I searched but everyone is showing how to start a tensorboard in google colab, did not find how to stop it.
I found a work around. First find the process ID of tensorboard by running this in colab
from tensorboard import notebook
notebook.list()
it will show this output and highlighted one (pid) is process id colab output
Next run this command to kill the process
!kill -9 2712