Background:

We monitor Jenkins with Prometheus and scrape the metrics produced by the metrics-plugin with the jmx-exporter (https://github.com/prometheus/jmx_exporter).

Furthermore, our slaves are ephemeral resulting in different slaves for different builds.

Motivation:

Exposed as mBeans and visible via JMX, we see metrics for our slaves denoted by e.g.

metrics_jenkins_node_scaler_int_i_192_168_148_102_java_4966cfa5_builds_98thPercentile 0.0

To make maximal use of this metric, Prometheus needs it so scrape in a form like

metrics_jenkins_node_builds{name="scaler_int_i_192_168_148_102_java_4966cfa5", quantile="0.98"} 0.0

Such a rewriting can be done with help of rules in the configuration of the JMX-Exporter: https://github.com/prometheus/jmx_exporter#configuration

Problem:

To generate rules, we need to apply a regex on the mBean. The prefix "node" would fit perfectly to file for. Unfortunately, the same prefix is used for the following, global node staticstic:

• jenkins.node.count.*
• jenkins.node.offline.*
• jenkins.node.online.*

This prohibits a filtering on node-specifics metrics.

Proposal:

Renaming of 

• jenkins.node.count.*
• jenkins.node.offline.*
• jenkins.node.online.*

to 

• jenkins.allnodes.count.*
• jenkins.allnodes.offline.*
• jenkins.allnodes.online.*

The affected Lines are marked over https://github.com/jenkinsci/metrics-plugin/blob/d94a4547b11263c094b2f713b37f7f0610882878/src/main/java/jenkins/metrics/impl/JenkinsMetricProviderImpl.java#L305,L319