Metricbeat's Ceph module queries the API provided by ceph-rest-api, a command-line tool provided with Ceph versions up to Luminous. This is documented here:
This was deprecated under Luminous and has been removed completely from the latest Ceph release, Mimic. (See "Notable Changes" on this page: https://ceph.com/releases/v12-2-5-luminous-released/ )
The replacement is the more comprehensive and more secure Restful plugin for the ceph-mgr service. This is documented here:
This uses HTTPS and requires authentication by the client: see
It would be great if MetricBeat understood the new Ceph API for collecting stats.