Docs » Available host and application monitors » Configure application receivers for languages » GenericJMX

GenericJMX 🔗

Description 🔗

The Splunk Distribution of OpenTelemetry Collector provides this integration as the genericjmx monitor using the Smart Agent Receiver. For a more flexible alternative, use the JMX monitor.

Note

This monitor is not available on Windows as collectd plugins are only supported in Linux and Kubernetes.

The Generix JMX integration monitors Java services that expose metrics on Java Management Extensions (JMX) using the GenericJMX plugin. The GenericJMX plugin reads Managed Beans (mBeans) from an MBeanServer using JMX. The monitor uses an embedded Java runtime.

The JMX is a generic framework to provide and query management information. The interface is used by the Java Virtual Machine (JVM) to provide information about the memory used and threads. These basic performance values can therefore be collected for every Java process without any support in the Java process itself.

Advanced Java processes can use the JMX interface to provide performance information themselves. The Apache Tomcat application server, for example, provides information on the number of requests processed, the number of bytes sent, processing time, and thread counts.

Note: C-based collectd plugins like this one are not available on Windows.

Benefits 🔗

After you configure the integration, you can access these features:

  • View metrics. You can create your own custom dashboards, and most monitors provide built-in dashboards as well. For information about dashboards, see View dashboards in Observability Cloud.

  • View a data-driven visualization of the physical servers, virtual machines, AWS instances, and other resources in your environment that are visible to Infrastructure Monitoring. For information about navigators, see Splunk Infrastructure Monitoring navigators.

  • Access the Metric Finder and search for metrics sent by the monitor. For information, see Use the Metric Finder.

Installation 🔗

Follow these steps to deploy this integration:

  1. Deploy the Splunk Distribution of OpenTelemetry Collector to your host or container platform:

  2. Configure the monitor, as described in the Configuration section.

  3. Restart the Splunk Distribution of OpenTelemetry Collector.

Configuration 🔗

To use this Smart Agent monitor with the Collector, include the smartagent receiver and service pipeline in your configuration file. The Smart Agent receiver is fully supported only on x86_64/amd64 platforms.

See the examples below for more details.

receivers:
  smartagent/genericjmx:
    type: collectd/genericjmx
    ...  # Additional config

To complete the monitor activation, you must also include the smartagent/genericjmx receiver item in a metrics pipeline. To do this, add the receiver item to the service > pipelines > metrics > receivers section of your configuration file. For example:

service:
  pipelines:
    metrics:
      receivers: [smartagent/genericjmx]

See configuration examples for specific use cases that show how the Splunk Distribution of OpenTelemetry Collector can integrate and complement existing environments.

Configuration settings 🔗

The following table shows the configuration options for this monitor:

Option

Required

Type

Description

host

yes

string

The host to connect to. JMX must be configured for remote access and accessible from the agent.

port

yes

integer

JMX connection port (not the RMI port) on the application. This corresponds to the com.sun.management.jmxremote.port Java property that should be set on the JVM when running the application.

name

no

string

serviceName

no

string

This is how the service type is identified in the Splunk Observability Cloud UI so that you can get built-in content.

serviceURL

no

string

The JMX connection string. This is rendered as a Go template and has access to the other values in this config. Note: Do not set this string directly; setting the host and port as specified above is preferred. The default value is service:jmx:rmi:///jndi/rmi://{{.Host}}:{{.Port}}/jmxrmi.

instancePrefix

no

string

Prefixes the generated plugin instance with prefix. If a second instancePrefix is specified in a referenced MBean block, the prefix specified in the Connection block will appear at the beginning of the plugin instance, and the prefix specified in the MBean block will be appended to it.

username

no

string

Username to authenticate to the server

password

no

string

User password to authenticate to the server

customDimensions

no

map of strings

Takes in key-value pairs of custom dimensions at the connection level.

mBeansToCollect

no

list of strings

A list of the MBeans defined in mBeanDefinitions to actually collect. If not provided, then all defined MBeans will be collected.

mBeansToOmit

no

list of strings

A list of the MBeans to omit. This is useful when only a few MBeans need to be omitted from the default list.

mBeanDefinitions

no

map of objects (see the following table)

Specifies how to map JMX MBean values to metrics. Specific service monitors such as Cassandra, Kafka, or ActiveMQ are pre-loaded with a set of mappings, and any that you add in this option will be merged with those. See GenericJMX plugin for more details.

The nested mBeanDefinitions configuration object has the following fields:

Option

Required

Type

Description

objectName

no

string

Sets the pattern which is used to retrieve MBeans from the MBeanServer. If more than one MBean is returned, you should use the instanceFrom option to make the identifiers unique.

instancePrefix

no

string

Prefixes the generated plugin instance with prefix.

instanceFrom

no

list of strings

The object names used by JMX to identify MBeans include “properties”, which are basically key-value pairs. If the given object name is not unique and multiple MBeans are returned, the values of those properties usually differ. You can use this option to build the plugin instance from the appropriate property values. This is optional and can be repeated to generate the plugin instance from multiple property values.

values

no

list of objects (see the following table)

The value blocks map one or more attributes of an MBean to a value list. There must be at least one value block within each MBean block.

dimensions

no

list of strings


The nested values configuration object has the following fields:

Option

Required

Type

Description

type

no

string

Sets the data set being used to handle the values of the MBean attribute.

table

no

bool

Set to true if the returned attribute is a composite type. If set to true, the keys within the composite type are appended to the type instance. The default value is false.

instancePrefix

no

string

Works like the option of the same name directly beneath the MBean block, but sets the type instance instead.

instanceFrom

no

list of strings

Works like the option of the same name directly beneath the MBean block, but sets the type instance instead.

attribute

no

string

Sets the name of the attribute from which to read the value. You can access the keys of composite types by using a dot to concatenate the key name to the attribute name. For example, “attrib0.key42”. If table is set to true, path must point to a composite type, otherwise it must point to a numeric type.

attributes

no

list of strings

The plural form of the attribute config above. Used to derive multiple metrics from a single MBean.

Example Configuration 🔗

This example configuration gets the thread count from a standard JMX MBean available on all Java JMX applications:

monitors:
 - type: collectd/genericjmx
   host: my-java-app
   port: 7099
   mBeanDefinitions:
     threading:
       objectName: java.lang:type=Threading
       values:
       - type: gauge
         table: false
         instancePrefix: jvm.threads.count
         attribute: ThreadCount

Metrics 🔗

Troubleshooting 🔗

The following Java properties show how to expose JMX ports to inbound connections. For more information, see Monitoring and Management Using JMX Technology in the Java documentation.

java \
  -Dcom.sun.management.jmxremote.port=5000 \
  -Dcom.sun.management.jmxremote.authenticate=false \
  -Dcom.sun.management.jmxremote.ssl=false \
  -Dcom.sun.management.jmxremote.rmi.port=5000 \
  ...

This works as long as the agent is allowed to access port 5000 on the Java app host. Note that this does not turn on authentication or encryption, but these can be added.

The following error messages assume the host config is set to 172.17.0.3 and the port set to 5000. Your host config and port settings might be different. The following sections show errors you might receive and their meanings:

Connection Refused 🔗

java \
  -Dcom.sun.management.jmxremote.port=5000 \
  -Dcom.sun.management.jmxremote.authenticate=false \
  -Dcom.sun.management.jmxremote.ssl=false \
  -Dcom.sun.management.jmxremote.rmi.port=5000 \
  ...

This error indicates that the JMX connect port is not open on the specified host. Confirm, using netstat/ss or some other tool, that this port is indeed open on the configured host and is listening on an appropriate address. If the agent is running on a remote server, JMX might not be listening on localhost only.

RMI Connection Issues 🔗

Creating MBean server connection failed: java.rmi.ConnectException: Connection refused to host: 172.17.0.3; nested exception is:
     java.net.ConnectException: Connection timed out (Connection timed out)

This indicates that the JMX connect port was reached successfully, but the RMI port that it was directed to is being blocked, probably by a firewall. Make sure the com.sun.management.jmxremote.rmi.port property in your Java app is set to the same port as the JMX connect port. There might be other variations of the error message that say Connection reset or Connection refused which indicate a similar cause.

Get help 🔗

If you are not able to see your data in Splunk Observability Cloud, try these tips:

To learn about even more support options, see Splunk Customer Success.