Expose metrics via JMX
Expose metrics via JMX

This allows Jenkins to work easily with other monitoring tools &
services that have ready-made JMX connectivity, such as:

1. DataDog: http://docs.datadoghq.com/integrations/java/
2. NewRelic: https://docs.newrelic.com/docs/agents/java-agent/custom-instrumentation/custom-jmx-instrumentation-yaml
3. Prometheus: https://github.com/prometheus/jmx_exporter
4. CollectD: https://collectd.org/wiki/index.php/Plugin:GenericJMX
5. IBM Tivoli: https://www.ibm.com/support/knowledgecenter/SSTFXA_6.3.0/com.ibm.itm.doc_6.3/builder/ab_ds_jmx_config.htm
6. Nagios: https://exchange.nagios.org/directory/Plugins/Java-Applications-and-Servers/check_jmx/details

jenkinsci/metrics-plugin,jenkinsci/metrics-plugin,jenkinsci/metrics-plugin