True when either count hit its cap of 1000: the real backlog is at least this large.
Pending deliveries that a worker could claim right now (partition rules applied).
Deliveries currently leased by a worker.
False when the subscription's transport cannot report a backlog (AWS — scale Lambda from the queue's own metrics).
claimable + inFlight — the value a scheduler should scale on.
Output of
WorkQueue.GetBacklog— the autoscaler metric for one subscription.