nodetool proxyhistograms

Provides a histogram of network operation statistics.

Provides a histogram of network operation statistics at the time of the command.

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. Typically, you use the command to see if requests encounter a slow node.

Synopsis

nodetool [connection_options] proxyhistograms
Table 1. Legend
Syntax conventions Description
UPPERCASE Literal keyword.
Lowercase Not literal.
Italics Variable value. Replace with a valid option or user-defined value.
[ ] Optional. Square brackets ( [ ] ) surround optional command arguments. Do not type the square brackets.
( ) Group. Parentheses ( ( ) ) identify a group to choose from. Do not type the parentheses.
| Or. A vertical bar ( | ) separates alternative elements. Type any one of the elements. Do not type the vertical bar.
... Repeatable. An ellipsis ( ... ) indicates that you can repeat the syntax element as often as required.
'Literal string' Single quotation ( ' ) marks must surround literal strings in CQL statements. Use single quotation marks to preserve upper case.
{ key:value } Map collection. Braces ( { } ) enclose map collections or key value pairs. A colon separates the key and the value.
<datatype1,datatype2> Set, list, map, or tuple. Angle brackets ( < > ) enclose data types in a set, list, map, or tuple. Separate the data types with a comma.
cql_statement; End CQL statement. A semicolon ( ; ) terminates all CQL statements.
[ -- ] Separate the command line options from the command arguments with two hyphens ( -- ). This syntax is useful when arguments might be mistaken for command line options.
' <schema> ... </schema> ' Search CQL only: Single quotation marks ( ' ) surround an entire XML schema declaration.
@xml_entity='xml_entity_type' Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrconfig files.

Definition

The short form and long form parameters are comma-separated.

Connection options

-h, --host hostname
The hostname or IP address of a remote node or nodes. When omitted, the default is the local machine.
-p, --port jmx_port
The JMX port number.
-pw, --password jmxpassword
The JMX password for authenticating with secure JMX. If a password is not provided, you are prompted to enter one.
-pwf, --password-file jmx_password_filepath
The filepath to the file that stores JMX authentication credentials.
-u, --username jmx_username
The user name for authenticating with secure JMX.

Command arguments

This command takes no arguments.

Examples

Get network statistics histogram

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.

nodetool proxyhistograms
proxy histograms
                Percentile      Read Latency     Write Latency     Range Latency
                (micros)          (micros)          (micros)
                50%                  1502.50            375.00            446.00
                75%                  1714.75            420.00            498.00
                95%                 31210.25            507.00            800.20
                98%                 36365.00            577.36            948.40
                99%                 36365.00            740.60           1024.39
                Min                   616.00            230.00            311.00
                Max                 36365.00          55726.00          59247.00
Useful metrics in the output include:
  • CAS Read Latency
  • CAS Write Latency
  • View Write Latency
CAS Read and Write Latency provides data for compare-and-set operations, while View Write Latency provides data for materialized view write operations. 
proxy histograms 
                    Percentile       Read Latency      Write Latency      Range Latency   CAS Read Latency  CAS Write Latency View Write Latency
                    (micros)           (micros)           (micros)           (micros)           (micros)           (micros)
                    50%                    454.83             379.02            1955.67               0.00               0.00               0.00
                    75%                   1358.10             943.13            4055.27               0.00               0.00               0.00
                    95%                   3379.39           12108.97           20924.30               0.00               0.00               0.00
                    98%                   7007.51          155469.30           89970.66               0.00               0.00               0.00
                    99%                   8409.01          155469.30          155469.30               0.00               0.00               0.00
                    Min                     73.46             126.94             126.94               0.00               0.00               0.00
                    Max                  14530.76          155469.30          155469.30               0.00               0.00               0.00