queue.count, user.count and domain.count count the whole cluster, and only the node with the metrics-calculation role works them out. Every node still stored them. On the others the queue gauge only moves with local queue events, so it had drifted below zero (production: node 0 at 18,446,744,073,709,551,596, node 1 at ...613, i.e. -20 and -3), and the account and domain counts stayed at 0. A reader taking the latest reading got whichever node wrote last. sample() now takes whether the node calculates them and leaves them out otherwise. A unit test covers both cases.