Note_Tech

All technological notes.

Project maintained by simonangel-fong Hosted on GitHub Pages — Theme by mattgraham

Kubernetes - Node: Manual Scheduler

Manual Scheduler
- Normally, the Kubernetes Scheduler decides where Pods run.
- can bypass it and manually assign Pods to nodes.
- used for testing, debugging, or in very small setups.
Pros
- Learning/demo purposes: understand scheduler internals.
- Debugging: check how a Pod behaves on a specific node.
- Tiny clusters / edge setups: where you don’t want or need the full scheduler.
Cons
- No filtering or scoring: you must know if the node has enough resources.
- Not scalable: every Pod must be assigned manually.
- Easy to make mistakes: wrong node, resource mismatch, Pod stuck in Pending.

apiVersion: v1
kind: Pod
metadata:
  name: nginx-manual
spec:
  containers:
    - name: nginx
      image: nginx
  nodeName: worker-node-1

Kubernetes will not invoke the scheduler at all.
The Pod goes straight to the kubelet on worker-node-1.
- If the node name is invalid or the node doesn’t have enough resources, the Pod stays in Pending state forever.

apiVersion: v1
kind: Binding
metadata:
  name: nginx
target:
  apiVersion: v1
  kind: Node
  name: worker-node-1