nodetool cfhistograms
Provides statistics about a table that could be used to plot a frequency function.
Provides statistics about a table that could be used to plot a frequency function.
Synopsis
nodetool <options> cfhistograms -- <keyspace> <table>
| Short | Long | Description |
|---|---|---|
-h |
--host |
Hostname or IP address |
-p |
--port |
Port number |
-pwf |
--password-file |
Password file path |
-pw |
--password |
Password |
-u |
--username |
User name |
-- |
Separates an option from an argument that could be mistaken for a option. | |
- keyspace is the name of a keyspace.
- table is the name of a table.
Description
The nodetool cfhistograms command provides statistics about a table, including read/write latency, partition size, column count, and number of SSTables. The report is incremental, not cumulative. It covers all operations since the last time you ran nodetool cfhistograms in this session. The use of the metrics-core library in Cassandra 2.1 makes the output more informative and easier to understand.
Example
For example, to get statistics about the libout table in the libdata keyspace on Linux, use this command:
$ install_location/bin/nodetool cfhistograms libdata liboutOutput is:
libdata/libout histograms
Percentile SSTables Write Latency Read Latency Partition Size Cell Count
(micros) (micros) (bytes)
50% 0.00 39.50 36.00 1597 42
75% 0.00 49.00 55.00 1597 42
95% 0.00 95.00 82.00 8239 258
98% 0.00 126.84 110.42 17084 446
99% 0.00 155.13 123.71 24601 770
Min 0.00 3.00 3.00 1110 36
Max 0.00 50772.00 314.00 126934 3973The output shows the percentile rank of read and write latency values, the partition size, and the cell count for the table.