JMX Exporter

JMX to Prometheus exporter: a collector that can configurably scrape and expose mBeans of a JMX target.

This exporter is intended to be run as a Java Agent, exposing a HTTP server and serving metrics of the local JVM. It can be also run as a standalone HTTP server and scrape remote JMX targets, but this has various disadvantages, such as being harder to configure and being unable to expose process metrics (e.g., memory and CPU usage). Running the exporter as a Java Agent is thus strongly encouraged.

Running the Java Agent

The Java agent is available in two versions with identical functionality:

• jmx_prometheus_javaagent-0.18.0.jar requires Java >= 7.
• jmx_prometheus_javaagent-0.18.0_java6.jar is compatible with Java 6.

Both versions are built from the same code and differ only in the versions of the bundled dependencies.

To run as a Java agent, download one of the JARs and run:

java -javaagent:./jmx_prometheus_javaagent-0.18.0.jar=12345:config.yaml -jar yourJar.jar

Metrics will now be accessible at http://localhost:12345/metrics. To bind the java agent to a specific IP change the port number to host:port.

A minimal config.yaml looks like this:

rules:
- pattern: ".*"

Example configurations can be found in the example_configs/ directory.

Running the Standalone HTTP Server

The HTTP server is available in two versions with identical functionality:

• jmx_prometheus_httpserver-0.18.0.jar requires Java >= 7.
• jmx_prometheus_httpserver-0.18.0_java6.jar is compatible with Java 6.

Both versions are built from the same code and differ only in the versions of the bundled dependencies.

To run the standalone HTTP server, download one of the JARs and run:

java -jar jmx_prometheus_httpserver-0.18.0.jar 12345 config.yaml

Metrics will now be accessible at http://localhost:12345/metrics. To bind the java agent to a specific IP change the port number to host:port.

The standalone HTTP server will read JMX remotely over the network. Therefore, you need to specify either hostPort or jmxUrl in config.yaml to tell the HTTP server where the JMX beans can be accessed.

A minimal config.yaml looks like this:

hostPort: localhost:9999
rules:
- pattern: ".*"

As stated above, it is recommended to run JMX exporter as a Java agent and not as a standalone HTTP server.

Building

./mvnw clean package to build.

Configuration

The configuration is in YAML. An example with all possible options:

---
startDelaySeconds: 0
hostPort: 127.0.0.1:1234
username: 
password: 
jmxUrl: service:jmx:rmi:///jndi/rmi://127.0.0.1:1234/jmxrmi
ssl: false
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"
    cache: false
    type: GAUGE
    attrNameSnakeCase: false

Metric names and label names are sanitized. All characters other than [a-zA-Z0-9:_] are replaced with underscores, and adjacent underscores are collapsed. There's no limitations on label values or the help text.

A minimal config is {}, which will connect to the local JVM and collect everything in the default format. Note that the scraper always processes all mBeans, even if they're not exported.

Example configurations for javaagents can be found at https://github.com/prometheus/jmx_exporter/tree/master/example_configs

Pattern input

The format of the input matches against the pattern is

domain<beanpropertyName1=beanPropertyValue1, beanpropertyName2=beanPropertyValue2, ...><key1, key2, ...>attrName: value

No escaping or other changes are made to these values, with the exception of if attrNameSnakeCase is set. The default help includes this string, except for the value.

Default format

The default format will transform beans in a way that should produce sane metrics in most cases. It is

domain_beanPropertyValue1_key1_key2_...keyN_attrName{beanpropertyName2="beanPropertyValue2", ...}: value

If a given part isn't set, it'll be excluded.

Integration Testing

The JMX exporter uses the AntuBLUE Test Engine and Testcontainers to run integration tests with different Java versions.

You need to have Docker installed to run these tests.

Build and run the integration tests:

./mvnw clean verify

Notes

• To run the integration tests in IntelliJ, you must build the project from the parent (root).

Debugging

You can start the JMX scraper in standalone mode in order to debug what is called

git clone https://github.com/prometheus/jmx_exporter.git
cd jmx_exporter
./mvnw package
java -cp collector/target/collector*.jar  io.prometheus.jmx.JmxScraper  service:jmx:rmi:your_url

To get finer logs (including the duration of each jmx call), create a file called logging.properties with this content:

handlers=java.util.logging.ConsoleHandler
java.util.logging.ConsoleHandler.level=ALL
io.prometheus.jmx.level=ALL
io.prometheus.jmx.shaded.io.prometheus.jmx.level=ALL

Add the following flag to your Java invocation:

-Djava.util.logging.config.file=/path/to/logging.properties

Installing

A Debian binary package is created as part of the build process and it can be used to install an executable into /usr/bin/jmx_exporter with configuration in /etc/jmx_exporter/jmx_exporter.yaml.