DataDog and JMX
External
Internal
Concepts
JMX Attribute
JMX Attribute Alias
If an alias is specified, it will become the metric name when displayed by the DataDog UI. Camel case will be converted to snake case. Dots are acceptable.
JMX Attribute Type
The JMX attribute type is specified as "metric_type" in configuration.
Gauge
The actual value. The agent does not attempt to calculate the rate, as in the counter's case.
Counter
For a "counter", the rate per second will be computed for this metric.
Configuration
The JMX configuration is located in /etc/dd-agent/conf.d/jmx.yaml.example.
After modification and removal of the ".example" suffix, restart datadog as root:
service datadog-agent restart
JMX integration with JBoss
Server Preparation
JBoss instances have to be configured to allow JMX agent access. Details on how to configure JBoss various JBoss versions running in various modes are available here:
Agent Classpath and Startup Options
Working jmx.yaml configuration:
init_config: custom_jar_paths: - /opt/jdg/bin/client/jboss-cli-client.jar instances: - jmx_url: "service:jmx:remote://1.2.3.4:4447" user: jmx password: *** java_bin_path: /opt/jdk/bin/java name: jdg1 tags: env: stage newTag: test conf: [...]
The specific value for "jmx_url" depends on the JBoss version and the mode it is running in. More details can be found here:
- For Standalone EAP 6
- For EAP 6 Host Controller
- For EAP 6 Domain Mode Server Node
- For Standalone EAP 7
- For EAP 7 Host Controller
- For EAP 7 Domain Mode Server Node
Make sure the JMX user has been configured on target JBoss instances, for symptoms see "JMX User Has not Been Configured on the Target JBoss Instance" section.
JMX Metric Specification
The MBeans are grouped per their JMX domains. Each attribute is specified by name, with an alias and its type.
Troubleshooting
Agent Process Signature
ps -ef | grep java | grep datadog dd-agent 14889 14841 0 Oct15 ? 00:05:47 \ /opt/jdk/bin/java -Xms50m -Xmx200m \ -classpath /opt/jdk/lib/tools.jar:/opt/datadog-agent/agent/checks/libs/jmxfetch-0.11.0-jar-with-dependencies.jar org.datadog.jmxfetch.App \ --check jmx.yaml --check_period 15000 --conf_directory /etc/dd-agent/conf.d --log_level INFO \ --log_location /var/log/datadog/jmxfetch.log --reporter statsd:localhost:8125 --status_location /opt/datadog-agent/run/jmx_status.yaml collect
Agent Reinitialization
service datadog-agent restart
Metric List
sudo /etc/init.d/datadog-agent jmx list_not_matching_attributes
Errors
JMX User Has Not Been Configured on the target JBoss Instance
2016-10-19 15:34:53,433 | ERROR| App | Cannot connect to instance service:jmx:remoting-jmx://1.2.3.4:4447 javax.security.sasl.SaslException: Authentication failed: all available authentication mechanisms failed: DIGEST-MD5: Server rejected authentication