Datastore reports whether the shared warehouse client has a live connection. It is load-bearing for the READ path: false is one of the two ways this answers 503.
Lenses is per-lens table availability, probed only when connected — so it is absent from a degraded report, which has nothing to say about tables it could not reach.
Lost is the count of facts the sink irrecoverably dropped since boot (warehouse.go). It is reported on the DEGRADED report too, and deliberately: a warehouse that is unreachable is exactly when facts start failing their deliveries, so suppressing the number here would hide it precisely when it moves. ANY NON-ZERO VALUE IS AN ALARM — it counts data the endpoint already answered 200 for.
Plane reports the event plane — the bus and the stream every accepted event is published to BEFORE any of it reaches the warehouse. It is load-bearing for the WRITE path, and it is here because its absence was a real outage: this endpoint answered 200/ok on warehouse connectivity alone while every POST /v1/event 503'd on a stream that could not bind, so 100% ingest loss was invisible to monitoring. A probe that cannot see the write path cannot report the write path.
Status is ok or degraded. Degraded is the 503 and means EITHER load-bearing dependency is down — the warehouse this subsystem reads, or the event plane it writes. It is not moved by a missing lens table, which is honest-empty.
