1 files changed, 34 insertions, 0 deletions
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/jmx/GarbageCollectionMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/system/jmx/GarbageCollectionMetrics.scala
new file mode 100644
index 00000000..b7d2fe6a
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/jmx/GarbageCollectionMetrics.scala
@@ -0,0 +1,34 @@
+package kamon.system.jmx
+
+import java.lang.management.{ GarbageCollectorMXBean, ManagementFactory }
+
+import kamon.metric.{ Entity, MetricsExtension, GenericEntityRecorder }
+import kamon.metric.instrument.{ DifferentialValueCollector, Time, InstrumentFactory }
+import scala.collection.JavaConverters._
+
+class GarbageCollectionMetrics(gc: GarbageCollectorMXBean, instrumentFactory: InstrumentFactory) extends GenericEntityRecorder(instrumentFactory) {
+
+  gauge("garbage-collection-count", DifferentialValueCollector(() ⇒ {
+    gc.getCollectionCount
+  }))
+
+  gauge("garbage-collection-time", Time.Milliseconds, DifferentialValueCollector(() ⇒ {
+    gc.getCollectionTime
+  }))
+
+}
+
+object GarbageCollectionMetrics {
+
+  def sanitizeCollectorName(name: String): String =
+    name.replaceAll("""[^\w]""", "-").toLowerCase
+
+  def register(metricsExtension: MetricsExtension): Unit = {
+
+    val instrumentFactory = metricsExtension.instrumentFactory("system-metric")
+    ManagementFactory.getGarbageCollectorMXBeans.asScala.filter(_.isValid) map { gc ⇒
+      val gcName = sanitizeCollectorName(gc.getName)
+      metricsExtension.register(Entity(s"$gcName-garbage-collector", "system-metric"), new GarbageCollectionMetrics(gc, instrumentFactory))
+    }
+  }
+}