The error message indicates that the head node of the Ray cluster is not reachable. This could be due to various reasons:
- Ensure that the VPC peering setup is correctly configured. Double-check that the VPC network specified for the Ray cluster allows traffic from the Colab Enterprise environment.
- Verify that the firewall rules allow incoming and outgoing traffic for the necessary ports used by Ray.
- Make sure that the service account used by your Colab environment has the necessary permissions to access resources in the specified project and location.
- Ensure that the Ray cluster on Vertex AI is in a healthy state and all necessary components are running.
- Confirm that the address provided to ray.init() is correct and matches the address of the Ray cluster on Vertex AI.
Here's a checklist to follow:
- Double-check the VPC peering setup and firewall rules to ensure they are configured correctly.
- Verify the permissions of the service account used by Colab Enterprise.
- Ensure the Ray cluster on Vertex AI is running and accessible.
- Confirm the correctness of the cluster address provided to ray.init().