proxyhistograms

Provides a histogram of network statistics.

Synopsis

nodetool <options> proxyhistograms

options are:

( -h | --host ) <host name> | <ip address>
( -p | --port ) <port number>
( -pw | --password ) <password >
( -u | --username ) <user name>

Legend
Angle brackets (< >) mean not literal, a variable Italics mean optional The pipe (\|) symbol means OR or AND/OR Ellipsis (...) means repeatable A semicolon that terminates CQL statements is not included in the synopsis.

Description

The output of this command shows the full request latency recorded by the coordinator. The output includes the percentile rank of read and write latency values for inter-node communication. Range latency is the latency of range scans, such as getting all partitions, executing an IN statement, or performing any selection that requires ALLOW FILTERING or index lookups. Typically, you use the command to see if requests encounter a slow node.

Examples

This example shows the output from nodetool proxyhistograms after running 4,500 insert statements and 45,000 select statements on a three ccm node-cluster on a local computer. The output shows an offset on the left and latencies in microseconds (µs) on the right. The offset corresponds to the x-axis in a histogram. It represents buckets of values, which are a series of ranges. Each offset includes the range of values greater than the previous offset and less than or equal to the current offset. Each offset is calculated by multiplying the previous offset by 1.2, rounding up, and removing duplicates.

$ nodetool proxyhistograms
proxy histograms

Read Latency (microseconds)
61214 us: 1

Write Latency (microseconds)
  103 us: 22
  124 us: 142
  149 us: 297
  179 us: 1190
  215 us: 1823
  258 us: 2091
  310 us: 1291
  372 us: 753
  446 us: 297
  535 us: 72
  642 us: 26
  770 us: 15
  924 us: 4
 1109 us: 0
 1331 us: 0
 1597 us: 0
 1916 us: 0
 2299 us: 0
 2759 us: 0
 3311 us: 1
 3973 us: 0
 4768 us: 0
 5722 us: 0
 6866 us: 0
 8239 us: 0
 9887 us: 0
11864 us: 0
14237 us: 0
17084 us: 0
20501 us: 0
24601 us: 0
29521 us: 0
35425 us: 0
42510 us: 0
51012 us: 1

Range Latency (microseconds)
  310 us: 1
  372 us: 139
  446 us: 1824
  535 us: 8933
  642 us: 6123
  770 us: 3672
  924 us: 2178
 1109 us: 1152
 1331 us: 673
 1597 us: 112
 1916 us: 15
 2299 us: 2
 2759 us: 1
 3311 us: 1
 3973 us: 0
 4768 us: 0
 5722 us: 0
 6866 us: 0
 8239 us: 1
 9887 us: 0
11864 us: 0
14237 us: 2
17084 us: 0
20501 us: 0
24601 us: 0
29521 us: 1
35425 us: 0
42510 us: 1
51012 us: 1