Overview#

There are a few points you should be aware of when working with Jupyter Notebooks on the jupyterhub server:

  • Sessions are persistent. If you close the browser tab without stopping the server before, you can revisit the jupyterhub site and carry on working

  • Closing browser’s tab or log-in out will not stop your session, your session will continue consuming resources (see next point)

  • It is preferable to close the session when you finish. This depends on the jupyter interface:

    • JupyterLab: File -> Hub Control Panel then stop

    • Classical Jupyter: Control Panel and then stop

../../../_images/stop-servers.gif

Note

If you are new to DKRZ and want to access our JupyterHub, please consult the Quick Start page.

Note

If the batch queue is filled with waiting jobs, it might take some time to start the notebook server. There is an internal timelimit specified until which the resources should be ready. If not the spawner will reject and ask you to start again (maybe with reduced resources specified).

Introductory presentation#

On September 1st, 2020, we deployed a new version of our Jupyterhub server. Check the Changelog for all notable changes. Furthermore, this release was presented in the DKRZ Tech Talks. You can view the talk on Youtube or download the slides.

Interface#

Jupyterlab is the default interface. However, you can switch from lab to classical notebook simply by removing the /lab before /tree in the URL. Undo this operation to go back to switch again to jupyterlab.

../../../_images/lab-tree.gif

Debugging and support?#

If you have issues or you have request for new features to jupyterhub, we suggest that you try one of the following steps:

  • By default, stdout and stderr of the SLURM batch job that is spawned by Jupyterhub is written to your HOME directory on the HPC system. In order to make it simple to locate the log file:

    • if you use the preset options form: the log file is named jupyterhub_slurmspawner_preset_<id>.log.

    • if you use the advanced options form: the log file is named jupyterhub_slurmspawner_advanced_<id>.log. You can even change the name of the output log file (Log File Name).

    • Log File Name also allows you to change the Path of the output log file to a diffrent directory where you have write permissions. Example: /path/to/your/scratch/name_of_your_logfile.

  • Use the search field in documentation, or look into the blog posts here, we have written some tutorials on well-known issues

  • Check your job information (services –> accounts), this is useful when the server does not start due to Priority or AssocMaxJobsLimit

../../../_images/squeue.png

If the above steps do not help, send an e-mail to support@dkrz.de.