nodetool proxyhistograms
Provides a histogram of network 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 <options> proxyhistograms
Tarball and Installer No-Services path:
<installation_location>/resources/cassandra/bin
Options
| Short | Long | Description |
|---|---|---|
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Hostname or IP address. |
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Port number. |
|
|
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. |
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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:
-
CAS Read Latency
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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. 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