Hi,
I’m encountering a slightly annoying characteristic with my BinderHub in that it seems to “go to sleep” after long periods of inactivity. This manifests as “Internal Server Error” or failure to launch server on the Binder page, and the repo/user pod not showing up when I run kubectl get pods.
The only way I’ve found to rectify this is to scale the hub (effectively a restart).
kubectl scale deployment hub --replicas=0 (wait for the hub pod to terminate)
kubectl scale deployment hub --replicas=1
This is really manual and makes me look silly when I want to demonstrate the BinderHub to other people 
Can anyone suggest what might be happening?
Thanks!
Config is below:
config:
BinderHub:
# connect image registry and set image prefix
use_registry: true
image_prefix: <redacted>
# jupyterhub IP address
hub_url: http://<redacted>
# enable authentication
auth_enabled: true
# allow customisation of web pages
template_path: /etc/binderhub/custom/templates
extra_static_path: /etc/binderhub/custom/static
extra_static_url_prefix: /extra_static/
template_variables:
EXTRA_STATIC_URL_PREFIX: "/extra_static/"
jupyterhub:
cull:
# cull every 11 minutes so it is out of phase
# with the proxy check-routes interval of five minutes
every: 660
timeout: 600
# maxAge is 6 hours: 6 * 3600 = 21600
maxAge: 21600
hub:
services:
binder:
oauth_redirect_uri: "http://<redacted>/oauth_callback"
oauth_client_id: "binder-oauth-client-test"
extraConfig:
hub_extra: |
c.JupyterHub.redirect_to_server = False
binder: |
from kubespawner import KubeSpawner
class BinderSpawner(KubeSpawner):
def start(self):
if 'image' in self.user_options:
# binder service sets the image spec via user options
self.image = self.user_options['image']
return super().start()
c.JupyterHub.spawner_class = BinderSpawner
singleuser:
# to make notebook servers aware of hub
cmd: jupyterhub-singleuser
# limit CPUs and RAM
memory:
limit: 1G
guarantee: 1G
cpu:
limit: .5
guarantee: .5
auth:
type: github
admin:
access: true
users:
- sgibson91
github:
clientId: "<redacted>"
clientSecret: "<redacted>"
callbackUrl: "http://<redacted>/hub/oauth_callback"
# pre-pull images onto pods so that users aren't left waiting as long
prePuller:
continuous:
enabled: true
scheduling:
# schedule 3 dummy pods to reduce user wait time
podPriority:
enabled: true
userPlaceholder:
# Specify three dummy user pods will be used as placeholders
replicas: 3
# enable user scheduler to facilitate the efficient scheduling of user pods
userScheduler:
enabled: true
# match core pods to nodes with label 'hub.jupyter.org/node-purpose=core'
corePods:
nodeAffinity:
# matchNodePurpose valid options:
# - ignore
# - prefer (the default)
# - require
matchNodePurpose: require
# allow customisation of web pages
initContainers:
- name: git-clone-templates
image: alpine/git
args:
- clone
- --single-branch
- --branch=master
- --depth=1
- --
- https://github.com/alan-turing-institute/hub23-custom-files
- /etc/binderhub/custom
securityContext:
runAsUser: 0
volumeMounts:
- name: custom-templates
mountPath: /etc/binderhub/custom
extraVolumes:
- name: custom-templates
emptyDir: {}
extraVolumeMounts:
- name: custom-templates
mountPath: /etc/binderhub/custom
# enable rbac
rbac:
enabled: true