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JMX Metric Scraper

Maven

This utility provides a way to query JMX metrics and export them to an OTLP endpoint. The JMX MBeans and their metric mappings are defined in YAML and reuse implementation from jmx-metrics instrumentation.

This is an alternative to the JMX Gatherer utility.

Release

This project is released as part of the OpenTelemetry Java Contrib project. The latest release is available from:

Usage

The general command to invoke JMX scraper is java -jar scraper.jar <config>, where scraper.jar is the packaged binary:

  • build/libs/opentelemetry-jmx-scraper-<version>.jar when building from sources
  • .jar file downloaded from Maven central or Release assets

Minimal configuration required

  • otel.jmx.service.url for example service:jmx:rmi:///jndi/rmi://server:9999/jmxrmi for server host on port 9999 with RMI JMX connector.
  • otel.jmx.target.system or otel.jmx.config

Configuration can be provided through:

  • command line arguments: java -jar scraper.jar -config otel.jmx.service.url=service:jmx:rmi:///jndi/rmi://tomcat:9010/jmxrmi otel.jmx.target.system=tomcat.
  • command line arguments JVM system properties: java -Dotel.jmx.service.url=service:jmx:rmi:///jndi/rmi://tomcat:9010/jmxrmi -Dotel.jmx.target.system=tomcat -jar scraper.jar.
  • java properties file: java -jar scraper.jar -config config.properties.
  • stdin: java -jar scraper.jar -config - where otel.jmx.target.system=tomcat and otel.jmx.service.url=service:jmx:rmi:///jndi/rmi://tomcat:9010/jmxrmi is written to stdin.
  • environment variables: OTEL_JMX_TARGET_SYSTEM=tomcat OTEL_JMX_SERVICE_URL=service:jmx:rmi:///jndi/rmi://tomcat:9010/jmxrmi java -jar scraper.jar

SDK autoconfiguration is being used, so all the configuration options can be set using the java properties syntax or the corresponding environment variables.

For example the otel.jmx.service.url option can be set with the OTEL_JMX_SERVICE_URL environment variable.

Configuration reference

config option default value description
otel.jmx.service.url - mandatory JMX URL to connect to the remote JVM
otel.jmx.target.system - comma-separated list of systems to monitor, mandatory unless otel.jmx.config is set
otel.jmx.target.source auto source of metrics definitions to use for otel.jmx.target.system, supported values are auto, instrumentation and legacy
otel.jmx.config empty comma-separated list of paths to custom YAML metrics definition, mandatory when otel.jmx.target.system is not set
otel.jmx.username - user name for JMX connection, mandatory when JMX authentication is set on target JVM withcom.sun.management.jmxremote.authenticate=true
otel.jmx.password - password for JMX connection, mandatory when JMX authentication is set on target JVM with com.sun.management.jmxremote.authenticate=true
otel.jmx.remote.registry.ssl false connect to an SSL-protected registry when enabled on target JVM with com.sun.management.jmxremote.registry.ssl=true
otel.jmx.remote.profile - SASL remote profile, supported values are SASL/PLAIN, SASL/DIGEST-MD5, SASL/CRAM-MD5, TLS SASL/PLAIN, TLS SASL/DIGEST-MD5 and TLS SASL/CRAM-MD5
otel.jmx.realm - Realm required by profile SASL/DIGEST-MD5 or TLS SASL/DIGEST-MD5

When both otel.jmx.target.system and otel.jmx.config configuration options are used at the same time:

  • otel.jmx.target.system provides ready-to-use metrics and otel.jmx.config allows to add custom definitions.
  • The metrics definitions will be the aggregation of both.
  • There is no guarantee on the priority or any ability to override the definitions.

If there is a need to override existing ready-to-use metrics or to keep control of the metrics definitions, using a custom YAML definition with otel.jmx.config is the recommended option.

Supported values for otel.jmx.target.system and support for otel.jmx.target.source and links to the metrics definitions:

otel.jmx.target.system description legacy instrumentation
activemq Apache ActiveMQ activemq.yaml activemq.yaml (doc)
cassandra Apache Cassandra cassandra.yaml
hbase Apache HBase hbase.yaml
hadoop Apache Hadoop hadoop.yaml hadoop.yaml (doc)
jetty Eclipse Jetty jetty.yaml jetty.yaml (doc)
jvm JVM runtime metrics jvm.yaml jvm.yaml (doc)
kafka Apache Kafka kafka.yaml
kafka-connect Kafka Connect kafka-connect.yaml
kafka-consumer Apache Kafka consumer kafka-consumer.yaml
kafka-producer Apache Kafka producer kafka-producer.yaml
solr Apache Solr solr.yaml
tomcat Apache Tomcat tomcat.yaml tomcat.yaml (doc)
wildfly Wildfly wildfly.yaml wildfly.yaml (doc)

The source of metrics definitions is controlled by otel.jmx.target.source:

  • auto (default): metrics definitions from instrumentation with fallback on legacy when not available.
  • legacy: metrics definitions embedded in jmx-scraper, almost equivalent to JMX Gatherer.
  • instrumentation: metrics definitions embedded in the instrumentation/jmx-metrics library.

Setting the value of otel.jmx.target.source allows to fit the following use-cases:

  • auto ensures that the latest metrics definitions in instrumentation (reference) are used when available, with fallback on legacy otherwise.
  • legacy keeps using definitions that are very close to JMX Gatherer. This is the recommended option if preserving compatibility is required.
  • instrumentation forces the use of metrics definitions from instrumentation, and supported otel.jmx.target.system values will update with that dependency.

The following SDK configuration options are also relevant

config option default value description
otel.metric.export.interval 1m (1 minute) metric export interval, also controls the JMX sampling interval
otel.metrics.exporter otlp comma-separated list of metrics exporters supported values are otlp and logging, additional values might be provided through extra libraries in the classpath
otel.service.name service name
otel.resource.attributes used to specify otel resource attributes, including service attributes. See the sdk configuration and service attributes

In addition to OpenTelemetry configuration, the following Java system properties can be provided through the command-line arguments, properties file or stdin and will be propagated to the JVM system properties:

  • javax.net.ssl.keyStore
  • javax.net.ssl.keyStorePassword
  • javax.net.ssl.trustStore
  • javax.net.ssl.trustStorePassword

Those JVM system properties can't be set through individual environment variables, but they can still be set through the standard JAVA_TOOL_OPTIONS environment variable using the -D prefix.

Troubleshooting

Exported metrics

In order to investigate when and what metrics are being captured and sent, setting the otel.metrics.exporter configuration option to include logging exporter provides log messages when metrics are being exported

JMX connection test

Connection to the remote JVM through the JMX can be tested by adding the -test argument. When doing so, the JMX Scraper will only test the connection to the remote JVM with provided configuration and exit.

  • Connection OK: JMX connection test OK message is written to standard output and exit status = 0
  • Connection ERROR: JMX connection test ERROR message is written to standard output and exit status = 1

Extra libraries in classpath

By default, only the RMI JMX connector is provided by the JVM, so it might be required to add extra libraries in the classpath when connecting to remote JVMs that are not directly accessible with RMI.

One known example of this is the Wildfly/Jboss HTTP management interface for which the jboss-client.jar needs to be used to support otel.jmx.service.url = service:jmx:remote+http://server:9999.

When doing so, the java -jar command can´t be used, we have to provide the classpath with -cp/--class-path/-classpath option and provide the main class file name:

java -cp scraper.jar:jboss-client.jar io.opentelemetry.contrib.jmxscraper.JmxScraper <config>

Migration from JMX Gatherer

The JMX Scraper aims to replace the JMX Gatherer tool and thus share most features and configuration with it.

Features not supported:

  • Define and capture metrics with custom Groovy definitions through otel.jmx.groovy.script; this is now replaced with YAML and the otel.jmx.config configuration option.
  • Ability to export to prometheus collector, only the OTLP exporter is included.

The YAML-based implementation is provided by java instrumentation and thus should be used for syntax details and documentation.

Like with the JMX Gatherer, the selection of provided metrics is still done with the otel.jmx.target.system configuration option.

However, there is now two distinct sets of metrics to select from using the otel.jmx.target.source configuration option:

In both cases, the metrics definitions themselves are embedded in the JMX Scraper binary, thus they will only change if the release version of the JMX Scraper binary changes.

By default, otel.jmx.target.source is auto, which means for each value of otel.jmx.target.system:

  • Metrics definitions from instrumentation will be used by default, if available.
  • Legacy metrics definitions equivalent to JMX Gatherer will be used as fallback.
  • Whenever new metrics definitions are being added or modified in instrumentation, those newer definitions will be used.

There are multiple possible strategies depending on the ability or willingness to embrace change in metrics definitions:

  • To preserve maximum compatibility, use legacy, though that means not benefiting from future updates and contributions.
  • To only get the most recent definitions, use instrumentation. This ensures only the reference definitions are used.
  • To embrace reference definitions whenever they become available, use auto, though the produced metrics may change when updating the JMX Scraper version.
  • For more complex migration strategies or tight control of metric definitions, use copies of the YAML metric definitions and provide them explicitly with otel.jmx.config.

When using otel.target.source=auto or otel.target.source=legacy, one or more legacy definitions might be used. If strict compatibility with metrics produced by JMX Gatherer is required, it is recommended to review the legacy metrics definitions YAML files, which contain comments on the minor differences from JMX Gatherer Groovy definitions.

Component owners

Learn more about component owners in component_owners.yml.