The number of input records processed by the circuit.
This metric tracks the end-to-end progress of the pipeline: the output
of this endpoint is equal to the output of the circuit after
processing total_processed_input_records records.
The counter never runs ahead of the endpoint's output. It advances to a
value N only once the endpoint has processed every batch derived from
the first N records received by the pipeline, which means transmitting
the batch, or discarding it while silent bootstrapping suppresses the
endpoint's output.
In a multihost pipeline, N counts the input records that all of the
hosts received, not only the endpoint's own host. (Each host counts
only its own input, and the coordinator adds up the hosts' counts as of
total_processed_steps.) If a host runs an older version that does
not report its count to the coordinator, N counts only the input
records that the endpoint's own host received.