Table statistics
For individual tables, the ColumnFamilyStoreMBean provides the same general latency attributes as StorageProxyMBean. Unlike StorageProxyMBean, ColumnFamilyStoreMBean has a number of other statistics that are important to monitor for performance trends. The most important of these are listed in the table.
| Attribute | Description |
|---|---|
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 for making sure operations happen 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.