|MemtableDataSize||The total size consumed by this table's data (not including metadata).|
|MemtableColumnsCount||Returns the total number of columns present in the memtable (across all keys).|
|MemtableSwitchCount||How many times the memtable has been flushed out.|
|RecentReadLatencyMicros||The average read latency since the last call to this bean.|
|RecentWriterLatencyMicros||The average write latency since the last call to this bean.|
|LiveSSTableCount||The number of live SSTables for this table.|
The recent read latency and write latency counters are important in making sure operations are happening in a consistent manner. If these counters start to increase after a period of staying flat, you probably need to add capacity to the cluster.
You can set a threshold and monitor LiveSSTableCount to ensure that the number of SSTables for a given table does not become too great.