[Core] report cluster config to gcs

[wxwmd]

I am using ray with autoscaler v2 and found that my program had issues during scaling up(related PR #62984). After investigation, I discovered this was because the cluster_config retrieved from GCS is None:

ray/python/ray/data/_internal/cluster_autoscaler/default_cluster_autoscaler_v2.py

Line 76 in f229d53

cluster_config = ray._private.state.state.get_cluster_config()

So I looked into it and found that this function is responsible for writing the cluster_config to GCS:

ray/python/ray/includes/gcs_client.pxi

Line 753 in f229d53

def report_cluster_config(

But this function was never actually called.

Therefore, in this PR, I modified autoscaler v2 to make it write the cluster_config to GCS.

[gemini-code-assist]

Code Review

This pull request implements reporting of the cluster configuration to the GCS in the Ray V2 autoscaler, allowing downstream consumers to access the latest node group configurations. The changes include a new conversion utility to transform internal autoscaling configurations into protobuf format and a reporting mechanism triggered during initialization and state updates. Review feedback highlights a critical issue regarding the loss of precision for fractional resources due to integer casting and suggests optimizing the reporting process by caching the last reported configuration to prevent redundant GCS writes and log flooding.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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