Intermittent problems rendering saved widget states (original) (raw)

February 21, 2025, 10:55pm 1

I’m looking for trouble shooting advice. I have a small installation of TLJH that I use for a class. We are using some ipywidget based tools, with “Save Widget State Automatically” set. I have set saving as the default for the whole hub.
Current configuration:

jupyter                           1.1.1
jupyter_client                    8.3.0
jupyter-console                   6.6.3
jupyter-contrib-core              0.4.2
jupyter-contrib-nbextensions      0.7.0
jupyter_core                      5.3.1
jupyter_datainputtable            0.8.0
jupyter-events                    0.11.0
jupyter-highlight-selected-word   0.2.0
jupyter-instructortools           0.8.0
jupyter-jsmol                     2022.1.0
jupyter-lsp                       2.2.5
jupyter_nbextensions_configurator 0.6.4
jupyter_Pandas_GUI                0.9.3
jupyter-resource-usage            1.1.0
jupyter_server                    2.15.0
jupyter_server_fileid             0.9.0
jupyter_server_terminals          0.5.3
jupyter_server_ydoc               0.8.0
jupyter-telemetry                 0.1.0
jupyter-ydoc                      0.2.4
jupyterhub                        5.2.1
jupyterlab                        4.3.4
jupyterlab_pygments               0.3.0
jupyterlab_server                 2.27.3
jupyterlab_widgets                3.0.13
jupyterpidaq_menu                 0.1.0

anywidget                         0.9.13
ipywidgets                        8.1.5
jupyterlab_widgets                3.0.13
widgetsnbextension                4.0.13
plotly                            6.00

Both my students and I are seeing intermittent cases where a notebook is saved, but when reopened we get the Error displaying widget: model not found error for some of the widgets. Some widgets that do not display are as simple as a textbox and some are complex widgets containing menus and even plotly plots.

I cannot seem to find any commonality among the cases where this is happening. I have two notebooks that I ran one after the other yesterday. One has this problem and the other does not. I am assuming the issue is with the way the server is saving the notebooks and an error is occurring. I have tried copying the notebooks to another instance of jupyter lab, but it appears the problem is with the saved widget state as things are no better, for the notebooks with problems.

I do not think I yet have enough information to create a useful bug report. Any suggestions on things to investigate or document that could help trace this problem down?

gutow March 21, 2025, 5:34pm 2

In case somebody else encounters intermittent failures to save everything in a notebook, here is what I believe was going on.

After checking all the hardware on the server for errors I found that the hard drive that user accounts were saved on has a few bad sectors. According to the diagnostics it had not reached the level where the sectors could not be reassigned to backup space, but apparently the very low failure rate just happened to be impacting hub users. Replacing the drive has reduced the occurrence of failures to get complete saves of files significantly. It is not clear to me why the hub users were so much more sensitive to this than others. Maybe the frequent automatic save was rapidly abusing the drive sectors with user accounts? I will keep an eye out for rapid degradation of the new hdd and report back if it happens.