Summary

Inventory and Metrics UIs use GET /api/metrics/source/{sourceId} (via context) to retrieve the metric indices fields list, which is later used to render their corresponding search bars.

The Hosts View doesn't need the fields list returned by GET /api/metrics/source/{sourceId} , yet it calls it to retrieve the metricAlias (via context), which is later used to create an ad-hoc data-view (which also retrieves a list of fields)

One problem with having GET /api/metrics/source/{sourceId} returning the fields list is that it increases the response size, and this endpoint should be only responsible for returning the Infra settings, not indices fields details, another problem is that code is old and it has a rather convoluted way to retrieve the fields list (see also the adapter code), making maintenance more challenging.

Solution

Similar to Logs UI, and because ad-hoc data view also contains the fields list, the idea is to create a client responsible for creating an ad-hoc data view from the metricsAlias returned by GET /api/metrics/source/{sourceId}.

The client will replace the manual retrieval of the fields list used in the GET /api/metrics/source/{sourceId} and deprecate the use_data_view hook used in the hosts view, and will be used in the frontend.