Comment (by Roland Haas):

Hmm that is no good. It seems as if it ran out of CPUs to allocate to your jupyter notbook. Right now there is 1 notebook running (mine), plus the hub and some infrastructure.

We limit each notebook to 2 cpu (there's 4 cpus on the VM that this runs in), and do not set an explicit guarantee. I will try and see if a limit without an explicit guarantee has the guarantee default to the limit (and also check on how many cpus are guaranteed to the other running containers). The docs https://zero-to-jupyterhub.readthedocs.io/en/latest/user-resources.html#set-user-memory-and-cpu-guarantees-limits seem to not indicate an implied guarantee.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2234/trouble-in-the-tutorial-server