package io.prometheus.client.hotspot;
import io.prometheus.client.Collector;
import io.prometheus.client.CounterMetricFamily;
import io.prometheus.client.GaugeMetricFamily;
import java.lang.management.ManagementFactory;
import java.lang.management.ClassLoadingMXBean;
import java.util.ArrayList;
import java.util.List;
/**
* Exports metrics about JVM classloading.
* <p>
* Example usage:
* <pre>
* {@code
* new ClassLoadingExports().register();
* }
* </pre>
* Example metrics being exported:
* <pre>
* jvm_classes_loaded{} 1000
* jvm_classes_loaded_total{} 2000
* jvm_classes_unloaded_total{} 500
* </pre>
*/
public class ClassLoadingExports extends Collector {
private final ClassLoadingMXBean clBean;
public ClassLoadingExports() {
this(ManagementFactory.getClassLoadingMXBean());
}
public ClassLoadingExports(ClassLoadingMXBean clBean) {
this.clBean = clBean;
}
void addClassLoadingMetrics(List<MetricFamilySamples> sampleFamilies) {
sampleFamilies.add(new GaugeMetricFamily(
"jvm_classes_loaded",
"The number of classes that are currently loaded in the JVM",
clBean.getLoadedClassCount()));
sampleFamilies.add(new CounterMetricFamily(
"jvm_classes_loaded_total",
"The total number of classes that have been loaded since the JVM has started execution",
clBean.getTotalLoadedClassCount()));
sampleFamilies.add(new CounterMetricFamily(
"jvm_classes_unloaded_total",
"The total number of classes that have been unloaded since the JVM has started execution",
clBean.getUnloadedClassCount()));
}
public List<MetricFamilySamples> collect() {
List<MetricFamilySamples> mfs = new ArrayList<MetricFamilySamples>();
addClassLoadingMetrics(mfs);
return mfs;
}
}