​​Monitoring Java processes with Prometheus

​​Monitoring Java processes with Prometheus

​​Tokuhiro Matsuno
​​LINE Corp
​​

​​Who am I?

  • ​​Working at LINE Corp.
  • ​​I’m writing web applications in Java 8
  • ​​Author of promgen(Ruby version)
  • ​​CPAN Author

​​Contributor of the client_java

​​
 
User-uploaded image: file.png

​​Why Prometheus?

  • ​​Store the metrics values
  • ​​Prometheus provides querying features.
  • ​​Render it using query
  • ​​Grafana is awesome
​​
​​
 
User-uploaded image: file.png

​​Monitoring Java processes with Prometheus

​​There are some options
  • ​​Dropwizard metrics → client_java
  • ​​client_java(In process jetty)

​​jmx_prometheus_javaagent

​​https://github.com/prometheus/jmx_exporter
  • ​​Aggregate metrics values using JMX
  • ​​-javaagent:jmx_prometheus_javaagent.jar=1234:config.yaml
  • ​​Easy to setup
  • ​​If it uses too much CPU time, application may get performance issue
  • ​​relabeling is hard
  • ​​in YAML
​​
 
User-uploaded image: file.png
​​
​​---
​​hostPort: 127.0.0.1:1234
​​jmxUrl: service:jmx:rmi:///jndi/rmi://127.0.0.1:1234/jmxrmi
​​lowercaseOutputName: false
​​lowercaseOutputLabelNames: false
​​whitelistObjectNames: ["org.apache.cassandra.metrics:*"]
​​blacklistObjectNames: ["org.apache.cassandra.metrics:type=ColumnFamily,*"]
​​rules:
​​  - pattern: "^org.apache.cassandra.metrics<type=(\w+), name=(\w+)><>Value: (\d+)"
​​    name: cassandra_$1_$2
​​    value: $3
​​    valueFactor: 0.001
​​    labels: {}
​​    help: "Cassandra metric $1 $2"
​​    type: GAUGE