Feature Request: add metrics from OpenSearch file_cache (:9200/_nodes/stats/file_cache)

[drewmiranda-gl]

As far as I can tell, metrics from file_cache are not exported for OpenSearch. These are very helpful metrics to monitor the health of using Searchable Snapshots and the search role with OpenSearch.

[Shivani3351]

Hi Team.
Please can you include this too .

Extend nodes search metrics to add scroll_current (integer) Number of scroll operations currently running

It is crucial data for our application and would be helpful if it were integrated.