progress

How far subscription has come over all partitions of its source: the sum, over each partition, of its progress there. In a partition this node runs, the worker's SubscriptionWorker.progress, which grows the moment an entry completes, even above an entry still running; in the others, the saved checkpoint (else 0), which another node moves forward. The sum changes when the subscription completed an entry: the snapshot subscription's is the validator of the cached counts, so a count after a write this node completed sees the write. Null when subscription is not registered.