Nodetool cfhistograms

cfhistograms <keyspace> <cfname>- This command provides statistics about a table, including number of SSTables, read/write latency, partition size and column count. cfhistograms covers all operations since the last time you ran the nodetool cfhistograms command. This command uses the following syntax:

nodetool cfhistograms keyspaces cfname

Example: To get statistics about the standard1 table in the keyspaces1 keyspace, use this command:

nodetool cfhistograms keyspaces1 standard1
Percentile SSTables value Write Latency Read Latency Partition Size Cell Count
50% 10.00 42.00 20.00 210 5
75% 20.00 42.00 24.00 280 5
95% 25.00 42.00 42.00 300 5
98% 25.00 42.00 770.00 310 5
99% 26.00 42.00 2759.00 310 5
Min 00.00 36.00 7.00 210 5
Max 26.00 42.00 35425.00 310 5

In this example, 95% of the write latency measurements were 42 microseconds (μs) or less, 95% of the read latencies were 42 μs or less, and 95% of the partitions are 300 bytes or less. The SSTables column means that the 95% read request refers to 25 SSTables.

Parameter Description
SSTables Distribution number of sstable per read
Write Latency Distribution of the Write Latency
Read Latency Distribution of the Read Latency
Partition Size Estimated row size
Cell Count Estimated column count

Nodetool Reference