Page History

...

It might be argued that the existing "replication-latency-ms"   metric already provides satisfactory information about the replication lag, but I think providing an exact amount of record lagging behind is beneficial in addition to providing a time-lag.No other alternatives were considered..

replication-latency-ms  is calculated in the producer callback: it is the difference between the system time at the moment of callback invocation and the timestamp of the original source record. 

This metric is useful for tracking time-based latency of the replication, but it does not provide information about count-based latency which the new replication-offset-lag  is aimed for.

Note: replication-latency-ms  may be inaccurate under specific circumstances: