ipython notebook kernel dies ("WebSocket ping timeout") when the SSH connection becomes idle

Question

I was trying to use tmux to start a remote ipython notebook on my Debian server. I then start browser on the Mac OS X local machine. After starting a long-run task, I detach the tmux session and exit the SSH connection.

However, after a while I came back and SSH back to the server, I found the following message in tmux session:

[W 19:15:52.617 NotebookApp] Notebook simplified_algo.ipynb is not trusted      # The first time I left 
[W 19:27:55.249 NotebookApp] WebSocket ping timeout after 119865 ms.  
[I 22:09:13.696 NotebookApp] Saving file at /simplified_algo.ipynb              # I then came back 
[W 22:09:13.698 NotebookApp] Saving untrusted notebook simplified_algo.ipynb
[W 22:15:18.390 NotebookApp] Notebook simplified_algo.ipynb is not trusted
[I 22:17:21.426 NotebookApp] Saving file at /simplified_algo.ipynb
[W 22:17:21.428 NotebookApp] Saving untrusted notebook simplified_algo.ipynb
[I 22:19:20.954 NotebookApp] Saving file at /simplified_algo.ipynb
[I 22:21:20.974 NotebookApp] Saving file at /simplified_algo.ipynb              # The second time I left
[W 22:38:33.102 NotebookApp] WebSocket ping timeout after 119992 ms.
[I 23:01:07.494 NotebookApp] Kernel shutdown: 75b0cf60-610e-4931-99cb-847d821a726b

It seems that the kernel dies when the SSH connection is halted and becomes idle. How can it be fixed? Any comment would be appreciated.

Answer 1

I've got this error of Websocket timeout (Websocket ping timeout after ... ms) using Keras library with IPython / Jupyter Notebook which is caused by a bug when dealing with progress bar. So you can, one of these solutions:

1. Simply put verbose=0 in all model.fit(...) instructions

2. Install keras-tqdm to manage progress bar

3. Redirect the output to a file