To improve resource management, every user server that’s not actively being used, it’s shut down by the jupyterhub-idle-culler Hub service. Thus, any user pod, will be taken down by the idle culler when they are in an idle state.
Since the server’s kernel activity counts as server activity, the idle-culler also operates at a kernel level. This means that if a user leaves a notebook with a running kernel, the kernel will be shut down, if idle for the specified
User server culling configuration#
To configure the server’s different culling options, these options must be specified on a per-hub basis, under the appropriate configuration file in
jupyterhub: cull: # Cull after 30min of inactivity every: 300 timeout: 1800 # No pods over 12h long maxAge: 43200
More culling options and information about them can be found in the idle-culler documentation.
Kernel culling configuration#
The kernel culling options are configured through the
jupyter_notebook_config.json file, located at
/usr/local/etc/jupyter/jupyter_notebook_config.json in the user pod. This file is injected into the pod’s container on startup, by defining its location and content under
You can modify the current culling options values, under
singleuser.extraFiles.data, in the
singleuser: extraFiles: jupyter_notebook_config.json: mountPath: /usr/local/etc/jupyter/jupyter_notebook_config.json data: MappingKernelManager: # shutdown kernels after no activity cull_idle_timeout: 3600 # check for idle kernels this often cull_interval: 300 # a kernel with open connections but no activity still counts as idle cull_connected: true
If a user leaves a notebook with a running kernel, the idle timeout will typically be the cull idle timeout of the server + the cull idle timeout set for the kernel, as culling the kernel will register activity, resetting the
no_activity timer for the server as a whole.