nodetool proxyhistograms
Provides a histogram of network statistics at the time of the command.
Synopsis
nodetool <options> proxyhistograms
Tarball and Installer No-Services path:
<installation_location>/resources/cassandra/bin
Short | Long | Description |
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Hostname or IP address. |
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Port number. |
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Password file path. |
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Password. |
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Remote JMX agent username. |
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Separates an option from an argument that could be mistaken for an option. |
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. 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.
$ 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
In DataStax Enterprise 5.1, three metrics have been added to the output:
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CAS Read Latency
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CAS Write Latency
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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. The results are slightly different from previous versions:
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