Hbase cluster Replication monitoring lag

[#1]

After setting up cluster replication in Hbase, we want to monitor replication lag between clusters.

> status 'replication' : Gives output like

SOURCE: PeerID=sep᐀node, AgeOfLastShippedOp=0, SizeOfLogQueue=0, TimeStampsOfLastShippedOp=Fri Aug 02 18:24:18 IST 2019, Replication Lag=346

SINK : AgeOfLastAppliedOp=0, TimeStampsOfLastAppliedOp=Tue Jul 30 17:45:24 IST 2019

Can anyone help what that Replication Lag is actually? How is calculated in terms of available metrics ?

Looked at the replication metrics. Didn't match any as specific as replication lag which Hbase provides.

[#2]

We are having the same question here. Nothing useful on available metrics on CDH 6.2.0