Core hosts
No core host has reported yet. A core host is a run, not a service: when no run is active nothing is wrong, and a host that finished shows as idle.
Configuration revisions
No configuration has been published or applied since this Api started. A host says which revision it applied when it sees one in the bucket; this table is empty until then, and starts empty again when the Api restarts.
Background jobs
What the jobs worker has been doing, by kind of job, from the last 200 jobs. A kind that is not here has not run lately; a worker that is not running shows jobs waiting and nothing finishing.