JMX Exporter

JMX to Prometheus exporter: a collector that can configurable 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 strongly encouraged.

Running the Java Agent

• jmx_prometheus_javaagent-0.19.0.jar

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

java -javaagent:./jmx_prometheus_javaagent-0.19.0.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

• jmx_prometheus_httpserver-0.19.0.jar

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

java -jar jmx_prometheus_httpserver-0.19.0.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
includeObjectNames: ["org.apache.cassandra.metrics:*"]
excludeObjectNames: ["org.apache.cassandra.metrics:type=ColumnFamily,*"]
autoExcludeObjectNameAttributes: true
excludeObjectNameAttributes:
  "java.lang:type=OperatingSystem":
    - "ObjectName"
  "java.lang:type=Runtime":
    - "ClassPath"
    - "SystemProperties"
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

Name	Description
startDelaySeconds	start delay before serving requests. Any requests within the delay period will result in an empty metrics set.
hostPort	The host and port to connect to via remote JMX. If neither this nor jmxUrl is specified, will talk to the local JVM.
username	The username to be used in remote JMX password authentication.
password	The password to be used in remote JMX password authentication.
jmxUrl	A full JMX URL to connect to. Should not be specified if hostPort is.
ssl	Whether JMX connection should be done over SSL. To configure certificates you have to set following system properties: -Djavax.net.ssl.keyStore=/home/user/.keystore -Djavax.net.ssl.keyStorePassword=changeit -Djavax.net.ssl.trustStore=/home/user/.truststore -Djavax.net.ssl.trustStorePassword=changeit
lowercaseOutputName	Lowercase the output metric name. Applies to default format and name. Defaults to false.
lowercaseOutputLabelNames	Lowercase the output metric label names. Applies to default format and labels. Defaults to false.
includeObjectNames	A list of ObjectNames to query. Defaults to all mBeans.
excludeObjectNames	A list of ObjectNames to not query. Takes precedence over includeObjectNames. Defaults to none.
autoExcludeObjectNameAttributes	Whether to use auto add ObjectName attributes that can't be converted to standard metrics types. Defaults to true.
excludeObjectNameAttributes	Optional a map of ObjectNames with a list of attribute names.
rules	A list of rules to apply in order, processing stops at the first matching rule. Attributes that aren't matched aren't collected. If not specified, defaults to collecting everything in the default format.
pattern	Regex pattern to match against each bean attribute. The pattern is not anchored. Capture groups can be used in other options. Defaults to matching everything.
attrNameSnakeCase	Converts the attribute name to snake case. This is seen in the names matched by the pattern and the default format. For example, anAttrName to an_attr_name. Defaults to false.
name	The metric name to set. Capture groups from the pattern can be used. If not specified, the default format will be used. If it evaluates to empty, processing of this attribute stops with no output.
value	Value for the metric. Static values and capture groups from the pattern can be used. If not specified the scraped mBean value will be used.
valueFactor	Optional number that value (or the scraped mBean value if value is not specified) is multiplied by, mainly used to convert mBean values from milliseconds to seconds.
labels	A map of label name to label value pairs. Capture groups from pattern can be used in each. name must be set to use this. Empty names and values are ignored. If not specified and the default format is not being used, no labels are set.
help	Help text for the metric. Capture groups from pattern can be used. name must be set to use this. Defaults to the mBean attribute description, domain, and name of the attribute.
cache	Whether to cache bean name expressions to rule computation (match and mismatch). Not recommended for rules matching on bean value, as only the value from the first scrape will be cached and re-used. This can increase performance when collecting a lot of mbeans. Defaults to false.
type	The type of the metric, can be GAUGE, COUNTER or UNTYPED. name must be set to use this. Defaults to UNTYPED.

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

NOTE

Both whitelistObjectNames and blacklistObjectNames are still supported for backward compatibility, but should be considered deprecated.

Pattern input

The format of the input matches against the pattern is

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

Part	Description
domain	Bean name. This is the part before the colon in the JMX object name.
beanPropertyName/Value	Bean properties. These are the key/values after the colon in the JMX object name.
keyN	If composite or tabular data is encountered, the name of the attribute is added to this list.
attrName	The name of the attribute. For tabular data, this will be the name of the column. If attrNameSnakeCase is set, this will be converted to snake case.
value	The value of the attribute.

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.

Examples

java.lang<type=Memory><HeapMemoryUsage>used: 914251736
java.lang<type=Memory><HeapMemoryUsage>max: 1610612736
java.lang<type=Threading><>thread_count: 140
java.lang<type=Threading><>peak_thread_count: 158
java.lang<name=G1 Old Generation, type=GarbageCollector><>CollectionTime: 0
java.lang<name=G1 Young Generation, type=GarbageCollector, key=CodeHeap 'profiled nmethods'><LastGcInfo, memoryUsageAfterGc>used: 26476672

To help us identity these, Numero added a patternMatchingString= to the HELP string of metrics. It contains the string that JMX Exporter matches our patterns againts.

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.

HTTP Authentication (optional)

HTTP BASIC authentication supports using the following configuration algorithms:

• plaintext - plaintext password
• SHA-1 - SHA-1(<salt>:<password>)
• SHA-256 - SHA-256(<salt>:<password>)
• SHA-512 - SHA-512(<salt>:<password>)
• PBKDF2WithHmacSHA1
• PBKDF2WithHmacSHA256
• PBKDF2WithHmacSHA512

---

Plaintext example:

httpServer:
  authentication:
    basic:
      username: Prometheus
      password: secret

---

SHA-256 example using a salted password SHA-256(<salt>:<password>) with a password of secret

httpServer:
  authentication:
    basic:
      username: Prometheus
      passwordHash: 2bf7ed4906ac065bde39f7508d6102a6cdd7153a929ea883ff6cd04442772c99
      algorithm: SHA-256
      salt: U9i%=N+m]#i9yvUV:bA/3n4X9JdPXf=n

---

PBKDF2WithHmacSHA256 example with a password of secret

httpServer:
  authentication:
    basic:
      username: Prometheus
      passwordHash: A1:0E:4E:62:F7:1E:0B:59:0A:32:EA:CC:7C:65:37:1F:6D:A6:F1:F1:ED:3F:73:ED:C9:65:19:37:21:5B:6D:4E:9D:C6:61:DF:B5:BF:BB:16:B8:9A:50:14:57:CE:3D:14:67:73:A3:71:1B:87:3B:C4:B1:0E:DC:2D:0B:10:65:D6:F5:B6:DA:07:DD:EE:DA:AC:9C:60:CD:B4:59:0C:C9:CB:A7:3D:7E:30:3E:43:83:E9:E4:13:34:A1:F1:87:5C:24:46:8E:13:90:A6:66:E1:A6:F3:0B:5A:E7:14:8A:98:6A:81:2B:B6:F8:EF:95:D4:82:7E:FB:5E:2D:D3:24:FE:96
      algorithm: PBKDF2WithHmacSHA256
      salt: U9i%=N+m]#i9yvUV:bA/3n4X9JdPXf=n

• iterations = 600000 (default value for PBKDF2WithHmacSHA256 )
• keyLength = 128 bits (default value)

Notes

• PBKDF2WithHmacSHA1 default iterations = 1300000
• PBKDF2WithHmacSHA256 default iterations = 600000
• PBKDF2WithHmacSHA256 default iterations = 210000
• default keyLength = 128 (bits)

Generation of passwordHash

• sha1sum, sha256sum, and sha512sum can be used to generate the passwordHash
• openssl can be used to generate a PBKDF2WithHmac based algorithm passwordHash

---

HTTPS support (optional)

HTTPS support can be configured using either a JKS or PKCS12 format keystore via two possible methods:

• Exporter YAML configuration

• System properties

Notes

• Keystore type is dependent on the Java version

• Exporter YAML configuration overrides System properties

Configuration (using Exporter YAML)

1. Add configuration to your exporter YAML file

httpServer:
  ssl:
    keyStore:
      filename: localhost.jks
      password: changeit
    certificate:
      alias: localhost

2. Create a keystore and add your certificate

Configuration (using System properties)

1. Add configuration to your exporter YAML file

httpServer:
  ssl:
    certificate:
      alias: localhost

2. Add your certificate to the application's Java keystore

The exporter YAML file alias should match the certificate alias of the certificate you want to use for the HTTPS server.

3. Define the application system properties for the Java keystore

-Djavax.net.ssl.keyStore=<keystore file> -Djavax.net.ssl.keyStorePassword=<keystore password>

---

HTTP Thread Pool Configuration (optional)

The exporter thread pool can be configured via the exporter YAML file.

By default, a maximum of 10 threads is used.

Configuration

httpServer:
  threads:
    minimum: 1
    maximum: 10
    keepAliveTime: 120 # seconds

• minimum - minimum number of threads
• maximum - maximum number of threads
• keepAliveTime - thread keep-alive time in seconds

Notes

• If the work queue is full, the request will be blocked until space is available in the work queue for the request.

Integration Test Suite

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 the integration test suite.

Build and run the integration test suite:

./mvnw clean verify

Notes

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

  • The Maven build copies the core artifacts as resources to the integration_tests project

• Additional information can be found in the Integration Test Suite readme.

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.