dandi / dandi-hub

Infrastructure and code for the dandihub
https://hub.dandiarchive.org
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Do we need 2 user- schedulers? #178

Open asmacdo opened 4 months ago

asmacdo commented 4 months ago
user-scheduler   2/2     2            2           5d2h   kube-scheduler   registry.k8s.io/kube-scheduler:v1.26.15   app=jupyterhub,component=user-scheduler,release=jupyterhub

The user-scheduler deployment current has a desired size 2

spec:
  replicas: 2

Only 1 user-scheduler pod can be active at a time.

1 user-scheduler pod acquires the leader-lock, and handles user requests for new hubs. The other user-scheduler just waits.

I0723 23:54:51.705523       1 leaderelection.go:352] lock is held by user-scheduler-fc9c5b9bf-2chsl_184ca957-05ce-404b-867c-4ff2438352d4 and has not yet expired
I0723 23:54:51.705546       1 leaderelection.go:253] failed to acquire lease jupyterhub/user-scheduler-lock

This is a good pattern for highly available applications, but

So its not clear if this is offering any benefit at all.