1577538 : login issue with jupyterhub on naf

Created: 2026-02-18T08:19:38Z - current status: new

Here’s the anonymized and summarized report of the issue:

Summary

A user is unable to log in to JupyterHub on the National Analysis Facility (NAF) since the previous day. The login attempt fails without further details provided.

Possible Causes & Solutions

  1. Project Permissions or Account Issues
  2. The user’s account or associated project may lack the necessary permissions to access JupyterHub.

  3. Next Step: Verify project membership and permissions via the NAF portal or contact support to confirm account status.

  4. No Available Worker Slots

  5. JupyterHub relies on worker nodes, which may be fully occupied.

  6. Next Step: Check the log files in the user’s AFS home directory (.jupyterhub.condor.err and .jupyterhub.condor.out) for messages like "no slots available".

  7. AFS or Authentication Problems

  8. Issues with AFS (Andrew File System) or authentication tokens could prevent login.

  9. Next Step: Ensure AFS is accessible and tokens are valid (e.g., via kinit and aklog commands).

  10. Conflicting Python Modules

  11. Custom Python modules in .local/ may cause startup failures.

  12. Next Step: Review the logs for errors related to module conflicts and temporarily rename .local/ to test.

  13. Network or Service Outage

  14. The NAF-JupyterHub service (naf-jhub.desy.de) may be temporarily unavailable.
  15. Next Step: Check the NAF status page or contact support for service updates.
  1. Check Logs:
  2. Access the AFS home directory and review .jupyterhub.condor.err and .jupyterhub.condor.out for error messages.

  3. Example commands: bash cat ~/.jupyterhub.condor.err cat ~/.jupyterhub.condor.out

  4. Verify Permissions:

  5. Confirm project membership and permissions via the NAF portal.

  6. Test Authentication:

  7. Run kinit and aklog to ensure Kerberos/AFS tokens are valid.

  8. Contact Support:

  9. If the issue persists, provide the log files to NAF support for further diagnosis.

Sources