K8s Ray Specifying GPU/Node Type

Saw this discussion here, but it feels like I’m missing the glue for all the appropriate pieces. So I’ll lay out what I know.

Let’s say I want to use the pod given in the docs for use with GPUs:

apiVersion: v1
kind: Pod
metadata:
 generateName: example-cluster-ray-worker
 spec:
  ...
  containers:
   - name: ray-node
     image: rayproject/ray:nightly-gpu
     ...
     resources:
      cpu: 1000m
      memory: 512Mi
     limits:
      memory: 512Mi
      nvidia.com/gpu: 1

Then for the sake of argument, let’s say I’ve added two nodes to my cluster (node a, node b), without labels, that are correctly set for allowing scaling of GPU resources and each has two different types of GPUs, (One with 8GB VRAM - node a, and the other with 20GB - node b).

The question is, how does one specify using ray resources that I want a 20gb GPU from node b rather than any GPU from either node a or b? Does this require adding node labels which ray can look at automagically?

I appreciate the help!

I think at some point we should provide a detailed guide for this sort of thing…

K8s part –
To describe a pod that gets scheduled on a node with a particular kind of GPU running on it, you’d probably want to add a taint to the node and a matching toleration to the pod.

Before I mention the Ray part – are you using the Ray Kubernetes operator or the Ray cluster launcher?