You can check for the string "digest mismatch" in the logs. Similarly, you can track the RR stats in nodetool netstats and the dropped mutations in nodetool tpstats.
To be clear though, RRs are a side-effect of nodes either dropping mutations or being unresponsive so they miss mutations. RRs do *not* cause nodes to be unresponsive or unavailable. RRs are Cassandra's way of automatically dealing with the "outages" -- it doesn't cause them. Cheers! >
