[Dashboard] Grafana dashboard iframe doesn't set cluster name, causing "No Data" for multi-cluster setups

[hedeesaa]

What happened + What you expected to happen

Issue:

We're running multiple Ray clusters in our Kubernetes environment. After the following merges:

• kuberay#2685
• ray#49498

Grafana now supports displaying metrics from multiple clusters in a single dashboard. However, we've encountered a client-side issue where the iframe embeds don't pass the Cluster (cluster name) as a variable. This results in "No Data" or a fallback to the default cluster being shown in the Grafana panels.

For example, the ClusterUtilization panel in the Ray Dashboard references the Cluster variable:

ray/python/ray/dashboard/client/src/pages/overview/cards/ClusterUtilizationCard.tsx

Lines 51 to 57 in 7beea56

	<Box
	component="iframe"
	title="Cluster Utilization"
	sx={{ flex: 1 }}
	src={`${grafanaHost}${path}&refresh&timezone=${currentTimeZone}${timeRangeParams}&var-SessionName=${sessionName}`}
	frameBorder="0"
	/>

Proposed Solution:

Update the dashboard iframes on the client side to include the cluster name in the query string, e.g.:

&var-Cluster=${cluster}

Related Workaround Attempt:

PR ray#51396 attempted to address this by enabling the "Include All" option in the Grafana dashboard. However, the actual kuberay/config/grafana/* configs haven't been updated accordingly.

Suggestion:

Ensure the iframe logic in the dashboard client app sets the appropriate var-Cluster parameter, and update the kuberay/config/grafana templates to reflect the multi-cluster setup.

Versions / Dependencies

Ray version: 2.44.1

Reproduction script

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Issue Severity

Medium: It is a significant difficulty but I can work around it.