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JMX Metric Scraper

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 currently a work-in-progress component not ready to be used in production. The end goal is to provide an alternative to the JMX Gatherer utility.

Usage

The general command to invoke JMX scraper is java -jar scraper.jar <config>, where scraper.jar is the build/libs/opentelemetry-jmx-scraper-<version>.jar packaged binary when building this module.

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.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

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 on the metrics definitions, using a custom YAML definition with otel.jmx.config is the recommended option.

Supported values for otel.jmx.target.system:

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

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

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>

Component owners

Learn more about component owners in component_owners.yml.