! kamon-system-metrics: introducing System and JVM metrics module

32 files changed, 1131 insertions, 0 deletions

diff --git a/kamon-system-metrics/src/main/resources/reference.conf b/kamon-system-metrics/src/main/resources/reference.conf
new file mode 100644
index 00000000..d6eb0576
--- /dev/null
+++ b/kamon-system-metrics/src/main/resources/reference.conf
@@ -0,0 +1,76 @@
+# ============================================ #
+# Kamon-System-Metrics Reference Configuration #
+# ============================================ #
+
+kamon {
+  metrics {
+    precision {
+      system {
+        process-cpu {
+          user =  {
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+          system =  {
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+        }
+
+        cpu {
+          user = {
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+          system = {
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+          wait = {
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+          idle ={
+            refresh-interval = 100 milliseconds
+            highest-trackable-value = 999999999
+            significant-value-digits = 2
+          }
+        }
+
+        network {
+          rx-bytes = ${kamon.metrics.precision.default-gauge-precision}
+          tx-bytes = ${kamon.metrics.precision.default-gauge-precision}
+          rx-errors = ${kamon.metrics.precision.default-gauge-precision}
+          tx-errors = ${kamon.metrics.precision.default-gauge-precision}
+        }
+
+        memory {
+          used = ${kamon.metrics.precision.default-gauge-precision}
+          free = ${kamon.metrics.precision.default-gauge-precision}
+          buffer = ${kamon.metrics.precision.default-gauge-precision}
+          cache = ${kamon.metrics.precision.default-gauge-precision}
+          swap-used = ${kamon.metrics.precision.default-gauge-precision}
+          swap-free = ${kamon.metrics.precision.default-gauge-precision}
+        }
+      }
+
+      jvm {
+        heap {
+          used = ${kamon.metrics.precision.default-gauge-precision}
+          max = ${kamon.metrics.precision.default-gauge-precision}
+          committed = ${kamon.metrics.precision.default-gauge-precision}
+        }
+
+        gc {
+          count = ${kamon.metrics.precision.default-gauge-precision}
+          time = ${kamon.metrics.precision.default-gauge-precision}
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/CPUMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/CPUMetrics.scala
new file mode 100644
index 00000000..c098d1e5
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/CPUMetrics.scala
@@ -0,0 +1,84 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric.instrument.{ Gauge, Histogram }
+import kamon.metric._
+import kamon.system.SigarExtensionProvider
+import org.hyperic.sigar.SigarProxy
+
+case class CPUMetrics(name: String) extends MetricGroupIdentity {
+  val category = CPUMetrics
+}
+
+object CPUMetrics extends MetricGroupCategory {
+  val name = "cpu"
+
+  case object User extends MetricIdentity { val name = "user" }
+  case object System extends MetricIdentity { val name = "system" }
+  case object Wait extends MetricIdentity { val name = "wait" }
+  case object Idle extends MetricIdentity { val name = "idle" }
+
+  case class CPUMetricRecorder(user: Gauge, system: Gauge, cpuWait: Gauge, idle: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      CPUMetricSnapshot(user.collect(context), system.collect(context), cpuWait.collect(context), idle.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class CPUMetricSnapshot(user: Histogram.Snapshot, system: Histogram.Snapshot, cpuWait: Histogram.Snapshot, idle: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = CPUMetricSnapshot
+
+    def merge(that: CPUMetricSnapshot, context: CollectionContext): GroupSnapshotType = {
+      CPUMetricSnapshot(user.merge(that.user, context), system.merge(that.system, context), cpuWait.merge(that.cpuWait, context), idle.merge(that.idle, context))
+    }
+
+    lazy val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      User -> user,
+      System -> system,
+      Wait -> cpuWait,
+      Idle -> idle)
+  }
+
+  val Factory = new MetricGroupFactory with SigarExtensionProvider {
+    def cpu = sigar.getCpu
+
+    type GroupRecorder = CPUMetricRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.system.cpu")
+
+      val userConfig = settings.getConfig("user")
+      val systemConfig = settings.getConfig("system")
+      val cpuWaitConfig = settings.getConfig("wait")
+      val idleConfig = settings.getConfig("idle")
+
+      new CPUMetricRecorder(
+        Gauge.fromConfig(userConfig, system)(() ⇒ cpu.getUser),
+        Gauge.fromConfig(systemConfig, system)(() ⇒ cpu.getSys),
+        Gauge.fromConfig(cpuWaitConfig, system)(() ⇒ cpu.getWait),
+        Gauge.fromConfig(idleConfig, system)(() ⇒ cpu.getIdle))
+    }
+  }
+}
+
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/GCMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/GCMetrics.scala
new file mode 100644
index 00000000..b5da600e
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/GCMetrics.scala
@@ -0,0 +1,75 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import java.lang.management.GarbageCollectorMXBean
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric._
+import kamon.metric.instrument.{ Gauge, Histogram }
+
+case class GCMetrics(name: String) extends MetricGroupIdentity {
+  val category = GCMetrics
+}
+
+object GCMetrics extends MetricGroupCategory {
+  val name = "gc"
+
+  case object CollectionCount extends MetricIdentity { val name = "collection-count" }
+  case object CollectionTime extends MetricIdentity { val name = "collection-time" }
+
+  case class GCMetricRecorder(count: Gauge, time: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      GCMetricSnapshot(count.collect(context), time.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class GCMetricSnapshot(count: Histogram.Snapshot, time: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = GCMetricSnapshot
+
+    def merge(that: GroupSnapshotType, context: CollectionContext): GroupSnapshotType = {
+      GCMetricSnapshot(count.merge(that.count, context), time.merge(that.time, context))
+    }
+
+    lazy val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      CollectionCount -> count,
+      CollectionTime -> time)
+  }
+
+  def Factory(gc: GarbageCollectorMXBean) = new MetricGroupFactory {
+
+    type GroupRecorder = GCMetricRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.jvm.gc")
+
+      val countConfig = settings.getConfig("count")
+      val timeConfig = settings.getConfig("time")
+
+      new GCMetricRecorder(
+        Gauge.fromConfig(countConfig, system)(() ⇒ gc.getCollectionCount),
+        Gauge.fromConfig(timeConfig, system, Scale.Milli)(() ⇒ gc.getCollectionTime))
+    }
+  }
+}
+
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/HeapMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/HeapMetrics.scala
new file mode 100644
index 00000000..09174f47
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/HeapMetrics.scala
@@ -0,0 +1,82 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import java.lang.management.ManagementFactory
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric._
+import kamon.metric.instrument.{ Gauge, Histogram }
+
+case class HeapMetrics(name: String) extends MetricGroupIdentity {
+  val category = HeapMetrics
+}
+
+object HeapMetrics extends MetricGroupCategory {
+  val name = "heap"
+
+  case object Used extends MetricIdentity { val name = "used-heap" }
+  case object Max extends MetricIdentity { val name = "max-heap" }
+  case object Committed extends MetricIdentity { val name = "committed-heap" }
+
+  case class HeapMetricRecorder(used: Gauge, max: Gauge, committed: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      HeapMetricSnapshot(used.collect(context), max.collect(context), committed.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class HeapMetricSnapshot(used: Histogram.Snapshot, max: Histogram.Snapshot, committed: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = HeapMetricSnapshot
+
+    def merge(that: GroupSnapshotType, context: CollectionContext): GroupSnapshotType = {
+      HeapMetricSnapshot(used.merge(that.used, context), max.merge(that.max, context), committed.merge(that.committed, context))
+    }
+
+    lazy val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      Used -> used,
+      Max -> max,
+      Committed -> committed)
+  }
+
+  val Factory = new MetricGroupFactory {
+
+    val memory = ManagementFactory.getMemoryMXBean
+    def heap = memory.getHeapMemoryUsage
+
+    type GroupRecorder = HeapMetricRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.jvm.heap")
+
+      val usedHeapConfig = settings.getConfig("used")
+      val maxHeapConfig = settings.getConfig("max")
+      val committedHeapConfig = settings.getConfig("committed")
+
+      new HeapMetricRecorder(
+        Gauge.fromConfig(usedHeapConfig, system)(() ⇒ heap.getUsed),
+        Gauge.fromConfig(maxHeapConfig, system)(() ⇒ heap.getMax),
+        Gauge.fromConfig(committedHeapConfig, system)(() ⇒ heap.getCommitted))
+    }
+  }
+}
+
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/MemoryMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/MemoryMetrics.scala
new file mode 100644
index 00000000..4f6cb1cd
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/MemoryMetrics.scala
@@ -0,0 +1,96 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric._
+import kamon.metric.instrument.Gauge.CurrentValueCollector
+import kamon.metric.instrument.{ Gauge, Histogram }
+import kamon.system.SigarExtensionProvider
+import org.hyperic.sigar.Mem
+
+case class MemoryMetrics(name: String) extends MetricGroupIdentity {
+  val category = MemoryMetrics
+}
+
+object MemoryMetrics extends MetricGroupCategory {
+  val name = "memory"
+
+  case object Used extends MetricIdentity { val name = "used" }
+  case object Free extends MetricIdentity { val name = "free" }
+  case object Buffer extends MetricIdentity { val name = "buffer" }
+  case object Cache extends MetricIdentity { val name = "cache" }
+  case object SwapUsed extends MetricIdentity { val name = "swap-used" }
+  case object SwapFree extends MetricIdentity { val name = "swap-free" }
+
+  case class MemoryMetricRecorder(used: Gauge, free: Gauge, buffer: Gauge, cache: Gauge, swapUsed: Gauge, swapFree: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      MemoryMetricSnapshot(used.collect(context), free.collect(context), buffer.collect(context), cache.collect(context), swapUsed.collect(context), swapFree.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class MemoryMetricSnapshot(used: Histogram.Snapshot, free: Histogram.Snapshot, buffer: Histogram.Snapshot, cache: Histogram.Snapshot, swapUsed: Histogram.Snapshot, swapFree: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = MemoryMetricSnapshot
+
+    def merge(that: GroupSnapshotType, context: CollectionContext): GroupSnapshotType = {
+      MemoryMetricSnapshot(used.merge(that.used, context), free.merge(that.free, context), buffer.merge(that.buffer, context), cache.merge(that.cache, context), swapUsed.merge(that.swapUsed, context), swapFree.merge(that.swapFree, context))
+    }
+
+    lazy val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      Used -> used,
+      Free -> free,
+      Buffer -> buffer,
+      Cache -> cache,
+      SwapUsed -> swapUsed,
+      SwapFree -> swapFree)
+  }
+
+  val Factory = new MetricGroupFactory with SigarExtensionProvider {
+    def mem = sigar.getMem
+    def swap = sigar.getSwap
+
+    type GroupRecorder = MemoryMetricRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.system.memory")
+
+      val usedConfig = settings.getConfig("used")
+      val freeConfig = settings.getConfig("free")
+      val bufferConfig = settings.getConfig("buffer")
+      val cacheConfig = settings.getConfig("cache")
+      val swapUsedConfig = settings.getConfig("swap-used")
+      val swapFreeConfig = settings.getConfig("swap-free")
+
+      new MemoryMetricRecorder(
+        Gauge.fromConfig(usedConfig, system)(() ⇒ mem.getUsed),
+        Gauge.fromConfig(freeConfig, system)(() ⇒ mem.getFree),
+        Gauge.fromConfig(bufferConfig, system)(() ⇒ swap.getUsed),
+        Gauge.fromConfig(cacheConfig, system)(() ⇒ swap.getFree),
+        Gauge.fromConfig(swapUsedConfig, system)(collectBuffer(mem)),
+        Gauge.fromConfig(swapFreeConfig, system)(collectCache(mem)))
+    }
+
+    private def collectBuffer(mem: Mem) = () ⇒ if (mem.getUsed() != mem.getActualUsed()) mem.getActualUsed() else 0L
+    private def collectCache(mem: Mem) = () ⇒ if (mem.getFree() != mem.getActualFree()) mem.getActualFree() else 0L
+  }
+}
\ No newline at end of file
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/NetworkMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/NetworkMetrics.scala
new file mode 100644
index 00000000..62fc3fcd
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/NetworkMetrics.scala
@@ -0,0 +1,94 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric._
+import kamon.metric.instrument.Gauge.CurrentValueCollector
+import kamon.metric.instrument.{ Gauge, Histogram }
+import kamon.system.SigarExtensionProvider
+import org.hyperic.sigar.{ NetInterfaceStat, SigarProxy }
+
+case class NetworkMetrics(name: String) extends MetricGroupIdentity {
+  val category = NetworkMetrics
+}
+
+object NetworkMetrics extends MetricGroupCategory {
+  val name = "network"
+
+  case object RxBytes extends MetricIdentity { val name = "rx-bytes" }
+  case object TxBytes extends MetricIdentity { val name = "tx-bytes" }
+  case object RxErrors extends MetricIdentity { val name = "rx-errors" }
+  case object TxErrors extends MetricIdentity { val name = "tx-errors" }
+
+  case class NetworkMetricRecorder(rxBytes: Gauge, txBytes: Gauge, rxErrors: Gauge, txErrors: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      NetworkMetricSnapshot(rxBytes.collect(context), txBytes.collect(context), rxErrors.collect(context), txErrors.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class NetworkMetricSnapshot(rxBytes: Histogram.Snapshot, txBytes: Histogram.Snapshot, rxErrors: Histogram.Snapshot, txErrors: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = NetworkMetricSnapshot
+
+    def merge(that: GroupSnapshotType, context: CollectionContext): GroupSnapshotType = {
+      NetworkMetricSnapshot(rxBytes.merge(that.rxBytes, context), txBytes.merge(that.txBytes, context), rxErrors.merge(that.rxErrors, context), txErrors.merge(that.txErrors, context))
+    }
+
+    val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      RxBytes -> rxBytes,
+      TxBytes -> txBytes,
+      RxErrors -> rxErrors,
+      TxErrors -> txErrors)
+  }
+
+  val Factory = new MetricGroupFactory with SigarExtensionProvider {
+
+    val interfaces: Set[String] = sigar.getNetInterfaceList.toSet
+
+    type GroupRecorder = NetworkMetricRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.system.network")
+
+      val rxBytesConfig = settings.getConfig("rx-bytes")
+      val txBytesConfig = settings.getConfig("tx-bytes")
+      val rxErrorsConfig = settings.getConfig("rx-errors")
+      val txErrorsConfig = settings.getConfig("tx-errors")
+
+      new NetworkMetricRecorder(
+        Gauge.fromConfig(rxBytesConfig, system)(collect(sigar, interfaces)(net ⇒ net.getRxBytes)),
+        Gauge.fromConfig(txBytesConfig, system)(collect(sigar, interfaces)(net ⇒ net.getTxBytes)),
+        Gauge.fromConfig(rxErrorsConfig, system)(collect(sigar, interfaces)(net ⇒ net.getRxErrors)),
+        Gauge.fromConfig(txErrorsConfig, system)(collect(sigar, interfaces)(net ⇒ net.getTxErrors)))
+    }
+
+    private def collect(sigar: SigarProxy, interfaces: Set[String])(block: NetInterfaceStat ⇒ Long) = () ⇒ {
+      interfaces.foldLeft(0L) { (totalBytes, interface) ⇒
+        {
+          val net = sigar.getNetInterfaceStat(interface)
+          totalBytes + block(net)
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/kamon-system-metrics/src/main/scala/kamon/metrics/ProcessCPUMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/metrics/ProcessCPUMetrics.scala
new file mode 100644
index 00000000..356504b7
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/metrics/ProcessCPUMetrics.scala
@@ -0,0 +1,76 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.metrics
+
+import akka.actor.ActorSystem
+import com.typesafe.config.Config
+import kamon.metric.instrument.{ Gauge, Histogram }
+import kamon.metric._
+import kamon.system.SigarExtensionProvider
+
+case class ProcessCPUMetrics(name: String) extends MetricGroupIdentity {
+  val category = ProcessCPUMetrics
+}
+
+object ProcessCPUMetrics extends MetricGroupCategory {
+  val name = "proc-cpu"
+
+  case object User extends MetricIdentity { val name = "user" }
+  case object System extends MetricIdentity { val name = "system" }
+
+  case class ProcessCPUMetricsRecorder(user: Gauge, system: Gauge)
+      extends MetricGroupRecorder {
+
+    def collect(context: CollectionContext): MetricGroupSnapshot = {
+      ProcessCPUMetricsSnapshot(user.collect(context), system.collect(context))
+    }
+
+    def cleanup: Unit = {}
+  }
+
+  case class ProcessCPUMetricsSnapshot(user: Histogram.Snapshot, system: Histogram.Snapshot)
+      extends MetricGroupSnapshot {
+
+    type GroupSnapshotType = ProcessCPUMetricsSnapshot
+
+    def merge(that: ProcessCPUMetricsSnapshot, context: CollectionContext): GroupSnapshotType = {
+      ProcessCPUMetricsSnapshot(user.merge(that.user, context), system.merge(that.system, context))
+    }
+
+    lazy val metrics: Map[MetricIdentity, MetricSnapshot] = Map(
+      User -> user,
+      System -> system)
+  }
+
+  val Factory = new MetricGroupFactory with SigarExtensionProvider {
+    def pid = sigar.getPid
+    def cpu = sigar.getProcCpu(pid)
+
+    type GroupRecorder = ProcessCPUMetricsRecorder
+
+    def create(config: Config, system: ActorSystem): GroupRecorder = {
+      val settings = config.getConfig("precision.system.process-cpu")
+
+      val userConfig = settings.getConfig("user")
+      val systemConfig = settings.getConfig("system")
+
+      new ProcessCPUMetricsRecorder(
+        Gauge.fromConfig(userConfig, system)(() ⇒ cpu.getUser),
+        Gauge.fromConfig(systemConfig, system)(() ⇒ cpu.getSys))
+    }
+  }
+}
+
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/SystemMetrics.scala b/kamon-system-metrics/src/main/scala/kamon/system/SystemMetrics.scala
new file mode 100644
index 00000000..e46fca24
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/SystemMetrics.scala
@@ -0,0 +1,64 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.system
+
+import java.lang.management.ManagementFactory
+
+import akka.actor._
+import akka.event.Logging
+import kamon.Kamon
+import kamon.metric.Metrics
+import kamon.metrics._
+import kamon.system.native.SigarLoader
+import scala.collection.JavaConverters._
+
+object SystemMetrics extends ExtensionId[SystemMetricsExtension] with ExtensionIdProvider {
+  override def lookup(): ExtensionId[_ <: Extension] = SystemMetrics
+
+  override def createExtension(system: ExtendedActorSystem): SystemMetricsExtension = new SystemMetricsExtension(system)
+}
+
+class SystemMetricsExtension(private val system: ExtendedActorSystem) extends Kamon.Extension {
+  import kamon.system.SystemMetricsExtension._
+
+  val log = Logging(system, classOf[SystemMetricsExtension])
+
+  log.info(s"Starting the Kamon(SystemMetrics) extension")
+
+  val systemMetricsExtension = Kamon(Metrics)(system)
+
+  systemMetricsExtension.register(CPUMetrics(CPU), CPUMetrics.Factory)
+  systemMetricsExtension.register(ProcessCPUMetrics(ProcessCPU), ProcessCPUMetrics.Factory)
+  systemMetricsExtension.register(NetworkMetrics(Network), NetworkMetrics.Factory)
+  systemMetricsExtension.register(MemoryMetrics(Memory), MemoryMetrics.Factory)
+  systemMetricsExtension.register(HeapMetrics(Heap), HeapMetrics.Factory)
+
+  garbageCollectors.map { gc ⇒ systemMetricsExtension.register(GCMetrics(gc.getName), GCMetrics.Factory(gc)) }
+}
+
+object SystemMetricsExtension {
+  val CPU = "cpu"
+  val ProcessCPU = "process-cpu"
+  val Network = "network"
+  val Memory = "memory"
+  val Heap = "heap"
+
+  val garbageCollectors = ManagementFactory.getGarbageCollectorMXBeans.asScala.filter(_.isValid)
+}
+
+trait SigarExtensionProvider {
+  lazy val sigar = SigarLoader.sigarProxy
+}
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/SigarLoader.scala b/kamon-system-metrics/src/main/scala/kamon/system/native/SigarLoader.scala
new file mode 100644
index 00000000..6af0a6d2
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/SigarLoader.scala
@@ -0,0 +1,131 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+
+package kamon.system.native
+
+import java.io._
+import java.util
+import java.util.logging.Logger
+import java.util.{ ArrayList, List }
+
+import org.hyperic.sigar.{ SigarProxy, SigarProxyCache }
+
+import scala.annotation.tailrec
+import scala.collection.JavaConversions._
+import scala.io.Source
+
+object SigarLoader {
+
+  val Version = "1.6.4"
+  val JavaLibraryPath = "java.library.path"
+  val TmpDir = "java.io.tmpdir"
+  val IndexFile = "/kamon/system/native/index"
+  val UsrPathField = "usr_paths"
+
+  private val log = Logger.getLogger("SigarLoader")
+
+  def sigarProxy = init(new File(System.getProperty(TmpDir)))
+
+  private[native] def init(baseTmp: File): SigarProxy = {
+    val tmpDir = createTmpDir(baseTmp)
+    for (lib ← loadIndex) copy(lib, tmpDir)
+
+    attachToLibraryPath(tmpDir)
+
+    try {
+      val sigar = SigarProxyCache.newInstance()
+      sigar.getPid
+      sigar
+    } catch {
+      case t: Throwable ⇒ {
+        log.severe("Failed to load sigar")
+        throw new RuntimeException(t)
+      }
+    }
+  }
+
+  private[native] val usrPathField = {
+    val usrPathField = classOf[ClassLoader].getDeclaredField(UsrPathField)
+    usrPathField.setAccessible(true)
+    usrPathField
+  }
+
+  private[native] def attachToLibraryPath(dir: File): Unit = {
+    val dirAbsolute = dir.getAbsolutePath
+    System.setProperty(JavaLibraryPath, newLibraryPath(dirAbsolute))
+    var paths = usrPathField.get(null).asInstanceOf[Array[String]]
+    if (paths == null) paths = new Array[String](0)
+    for (path ← paths) if (path == dirAbsolute) return
+    val newPaths = util.Arrays.copyOf(paths, paths.length + 1)
+    newPaths(newPaths.length - 1) = dirAbsolute
+    usrPathField.set(null, newPaths)
+  }
+
+  private[native] def newLibraryPath(dirAbsolutePath: String): String = {
+    Option(System.getProperty(JavaLibraryPath)).fold(dirAbsolutePath)(oldValue ⇒ s"$dirAbsolutePath${File.pathSeparator}$oldValue")
+  }
+
+  private[native] def copy(lib: String, tmpDir: File) {
+    val target = new File(tmpDir, lib)
+    if (target.exists()) return
+    write(classOf[Loader].getResourceAsStream(lib), target)
+  }
+
+  private[native] def createTmpDir(baseTmp: File): File = {
+    val tmpDir = new File(baseTmp, s"sigar-$Version")
+    if (!tmpDir.exists()) {
+      if (!tmpDir.mkdirs()) throw new RuntimeException(s"Could not create temp sigar directory: ${tmpDir.getAbsolutePath}")
+    }
+    if (!tmpDir.isDirectory) throw new RuntimeException(s"sigar temp directory path is not a directory: ${tmpDir.getAbsolutePath}")
+    if (!tmpDir.canWrite()) throw new RuntimeException(s"sigar temp directory not writeable: ${tmpDir.getAbsolutePath}")
+    tmpDir
+  }
+
+  private[native] def loadIndex(): List[String] = {
+    val libs = new ArrayList[String]()
+    val is = classOf[Loader].getResourceAsStream(IndexFile)
+
+    for (line ← Source.fromInputStream(is).getLines()) {
+      val currentLine = line.trim()
+      libs add currentLine
+    }
+    libs
+  }
+
+  private[native] def write(input: InputStream, to: File) {
+    val out = new FileOutputStream(to)
+    try {
+      transfer(input, out)
+    } finally {
+      out.close()
+    }
+  }
+
+  private[native] def transfer(input: InputStream, out: OutputStream) {
+    val buffer = new Array[Byte](8192)
+
+    @tailrec def transfer() {
+      val read = input.read(buffer)
+      if (read >= 0) {
+        out.write(buffer, 0, read)
+        transfer()
+      }
+    }
+    transfer()
+  }
+
+  class Loader private[native]
+}
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/index b/kamon-system-metrics/src/main/scala/kamon/system/native/index
new file mode 100644
index 00000000..ebc7f952
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/index
@@ -0,0 +1,22 @@
+libsigar-amd64-freebsd-6.so
+libsigar-amd64-linux.so
+libsigar-amd64-solaris.so
+libsigar-ia64-hpux-11.sl
+libsigar-ia64-linux.so
+libsigar-pa-hpux-11.sl
+libsigar-ppc64-aix-5.so
+libsigar-ppc64-linux.so
+libsigar-ppc-aix-5.so
+libsigar-ppc-linux.so
+libsigar-s390x-linux.so
+libsigar-sparc64-solaris.so
+libsigar-sparc-solaris.so
+libsigar-universal64-macosx.dylib
+libsigar-universal-macosx.dylib
+libsigar-x86-freebsd-5.so
+libsigar-x86-freebsd-6.so
+libsigar-x86-linux.so
+libsigar-x86-solaris.so
+sigar-amd64-winnt.dll
+sigar-x86-winnt.dll
+
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-freebsd-6.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-freebsd-6.so
new file mode 100644
index 00000000..3e94f0d2
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-freebsd-6.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-linux.so
new file mode 100644
index 00000000..5a2e4c24
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-solaris.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-solaris.so
new file mode 100644
index 00000000..6396482a
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-amd64-solaris.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-hpux-11.sl b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-hpux-11.sl
new file mode 100644
index 00000000..d92ea4a9
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-hpux-11.sl
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-linux.so
new file mode 100644
index 00000000..2bd2fc8e
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ia64-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-pa-hpux-11.sl b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-pa-hpux-11.sl
new file mode 100644
index 00000000..0dfd8a11
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-pa-hpux-11.sl
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-aix-5.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-aix-5.so
new file mode 100644
index 00000000..7d4b5199
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-aix-5.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-linux.so
new file mode 100644
index 00000000..4394b1b0
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-aix-5.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-aix-5.so
new file mode 100644
index 00000000..35fd8288
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-aix-5.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-linux.so
new file mode 100644
index 00000000..a1ba2529
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-ppc64-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-s390x-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-s390x-linux.so
new file mode 100644
index 00000000..c275f4ac
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-s390x-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc-solaris.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc-solaris.so
new file mode 100644
index 00000000..aa847d2b
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc-solaris.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc64-solaris.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc64-solaris.so
new file mode 100644
index 00000000..6c4fe809
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-sparc64-solaris.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal-macosx.dylib b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal-macosx.dylib
new file mode 100644
index 00000000..27ab1071
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal-macosx.dylib
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal64-macosx.dylib b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal64-macosx.dylib
new file mode 100644
index 00000000..0c721fec
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-universal64-macosx.dylib
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-5.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-5.so
new file mode 100644
index 00000000..8c50c611
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-5.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-6.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-6.so
new file mode 100644
index 00000000..f0800274
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-freebsd-6.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-linux.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-linux.so
new file mode 100644
index 00000000..a0b64edd
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-linux.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-solaris.so b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-solaris.so
new file mode 100644
index 00000000..c6452e56
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/libsigar-x86-solaris.so
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-amd64-winnt.dll b/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-amd64-winnt.dll
new file mode 100644
index 00000000..1ec8a035
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-amd64-winnt.dll
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-x86-winnt.dll b/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-x86-winnt.dll
new file mode 100644
index 00000000..6afdc016
--- /dev/null
+++ b/kamon-system-metrics/src/main/scala/kamon/system/native/sigar-x86-winnt.dll
diff --git a/kamon-system-metrics/src/test/scala/kamon/metrics/SystemMetricsSpec.scala b/kamon-system-metrics/src/test/scala/kamon/metrics/SystemMetricsSpec.scala
new file mode 100644
index 00000000..ed10903f
--- /dev/null
+++ b/kamon-system-metrics/src/test/scala/kamon/metrics/SystemMetricsSpec.scala
@@ -0,0 +1,331 @@
+/* =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+
+package kamon.metric
+
+import akka.actor.ActorSystem
+import akka.testkit.{ TestKitBase, TestProbe }
+import com.typesafe.config.ConfigFactory
+import kamon.Kamon
+import kamon.metric.Subscriptions.TickMetricSnapshot
+import kamon.metrics.HeapMetrics.HeapMetricSnapshot
+import kamon.metrics.MemoryMetrics.MemoryMetricSnapshot
+import kamon.metrics.NetworkMetrics.NetworkMetricSnapshot
+import kamon.metrics.ProcessCPUMetrics.ProcessCPUMetricsSnapshot
+import kamon.metrics._
+import kamon.metrics.CPUMetrics.CPUMetricSnapshot
+import kamon.metrics.GCMetrics.GCMetricSnapshot
+import kamon.system.SystemMetricsExtension
+import org.scalatest.{ Matchers, WordSpecLike }
+
+import scala.concurrent.duration._
+
+class SystemMetricsSpec extends TestKitBase with WordSpecLike with Matchers {
+  implicit lazy val system: ActorSystem = ActorSystem("system-metrics-spec", ConfigFactory.parseString(
+    """
+      |akka {
+      |  extensions = ["kamon.system.SystemMetrics"]
+      |}
+      |
+      |kamon.metrics {
+      |
+      |  disable-aspectj-weaver-missing-error = true
+      |
+      |  tick-interval = 1 second
+      |
+      |  system {
+      |     cpu {
+      |        user {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |        system {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |        wait {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |        idle {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |     }
+      |     process-cpu {
+      |        user {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |        system {
+      |            highest-trackable-value = 999999999
+      |            significant-value-digits = 2
+      |        }
+      |     }
+      |     memory {
+      |        used {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |        free {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |        buffer {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |        cache {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |        swap-used {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |        swap-free {
+      |          highest-trackable-value = 3600000000000
+      |          significant-value-digits = 2
+      |        }
+      |     }
+      |     network {
+      |        rx-bytes {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        tx-bytes {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        rx-errors {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        tx-errors {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |     }
+      |     heap {
+      |        used {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        max {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        committed {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |     }
+      |     gc {
+      |        count {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |        time {
+      |            highest-trackable-value = 3600000000000
+      |            significant-value-digits = 2
+      |        }
+      |     }
+      |  }
+      |}
+    """.stripMargin))
+
+  "the Kamon  CPU Metrics" should {
+    "record user, system, wait, idle metrics" in new CPUMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val CPUMetrics = expectCPUMetrics(metricsListener, 3 seconds)
+      CPUMetrics.user.max should be > 0L
+      CPUMetrics.system.max should be > 0L
+      CPUMetrics.cpuWait.max should be > 0L
+      CPUMetrics.idle.max should be > 0L
+    }
+  }
+  "the Kamon GC Metrics" should {
+    "record count, time metrics" in new GCMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val GCMetrics = expectGCMetrics(metricsListener, 3 seconds)
+      GCMetrics.count.max should be > 0L
+      GCMetrics.time.max should be > 0L
+    }
+  }
+
+  "the Kamon Heap Metrics" should {
+    "record used, max, commited metrics" in new HeapMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val HeapMetrics = expectHeapMetrics(metricsListener, 3 seconds)
+      HeapMetrics.used.max should be >= 0L
+      HeapMetrics.max.max should be >= 0L
+      HeapMetrics.committed.max should be >= 0L
+    }
+  }
+
+  "the Kamon Memory Metrics" should {
+    "record used, free, buffer, cache, swap used, swap free metrics" in new MemoryMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val MemoryMetrics = expectMemoryMetrics(metricsListener, 3 seconds)
+      MemoryMetrics.used.max should be >= 0L
+      MemoryMetrics.free.max should be >= 0L
+      MemoryMetrics.buffer.max should be >= 0L
+      MemoryMetrics.cache.max should be >= 0L
+      MemoryMetrics.swapUsed.max should be >= 0L
+      MemoryMetrics.swapFree.max should be >= 0L
+    }
+  }
+
+  "the Kamon Network Metrics" should {
+    "record rxBytes, txBytes, rxErrors, txErrors metrics" in new NetworkMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val NetworkMetrics = expectNetworkMetrics(metricsListener, 3 seconds)
+      NetworkMetrics.rxBytes.max should be >= 0L
+      NetworkMetrics.txBytes.max should be >= 0L
+      NetworkMetrics.rxErrors.max should be >= 0L
+      NetworkMetrics.txErrors.max should be >= 0L
+    }
+  }
+
+  "the Kamon Process CPU Metrics" should {
+    "record user, system metrics" in new ProcessCPUMetricsListenerFixture {
+      val metricsListener = subscribeToMetrics()
+
+      val ProcessCPUMetrics = expectProcessCPUMetrics(metricsListener, 3 seconds)
+      ProcessCPUMetrics.user.max should be > 0L
+      ProcessCPUMetrics.system.max should be > 0L
+    }
+  }
+
+  def expectCPUMetrics(listener: TestProbe, waitTime: FiniteDuration): CPUMetricSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+    val cpuMetricsOption = tickSnapshot.metrics.get(CPUMetrics(SystemMetricsExtension.CPU))
+    cpuMetricsOption should not be empty
+    cpuMetricsOption.get.asInstanceOf[CPUMetricSnapshot]
+  }
+
+  trait CPUMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(CPUMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+
+  def expectGCMetrics(listener: TestProbe, waitTime: FiniteDuration): GCMetricSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+
+    val gcMetricsOption = tickSnapshot.metrics.get(GCMetrics(SystemMetricsExtension.garbageCollectors(0).getName))
+    gcMetricsOption should not be empty
+    gcMetricsOption.get.asInstanceOf[GCMetricSnapshot]
+  }
+
+  trait GCMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(GCMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+
+  def expectHeapMetrics(listener: TestProbe, waitTime: FiniteDuration): HeapMetricSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+    val heapMetricsOption = tickSnapshot.metrics.get(HeapMetrics(SystemMetricsExtension.Heap))
+    heapMetricsOption should not be empty
+    heapMetricsOption.get.asInstanceOf[HeapMetricSnapshot]
+  }
+
+  trait HeapMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(HeapMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+
+  def expectMemoryMetrics(listener: TestProbe, waitTime: FiniteDuration): MemoryMetricSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+    val memoryMetricsOption = tickSnapshot.metrics.get(MemoryMetrics(SystemMetricsExtension.Memory))
+    memoryMetricsOption should not be empty
+    memoryMetricsOption.get.asInstanceOf[MemoryMetricSnapshot]
+  }
+
+  trait MemoryMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(MemoryMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+
+  def expectNetworkMetrics(listener: TestProbe, waitTime: FiniteDuration): NetworkMetricSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+    val networkMetricsOption = tickSnapshot.metrics.get(NetworkMetrics(SystemMetricsExtension.Network))
+    networkMetricsOption should not be empty
+    networkMetricsOption.get.asInstanceOf[NetworkMetricSnapshot]
+  }
+
+  trait NetworkMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(NetworkMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+
+  def expectProcessCPUMetrics(listener: TestProbe, waitTime: FiniteDuration): ProcessCPUMetricsSnapshot = {
+    val tickSnapshot = within(waitTime) {
+      listener.expectMsgType[TickMetricSnapshot]
+    }
+    val processCPUMetricsOption = tickSnapshot.metrics.get(ProcessCPUMetrics(SystemMetricsExtension.ProcessCPU))
+    processCPUMetricsOption should not be empty
+    processCPUMetricsOption.get.asInstanceOf[ProcessCPUMetricsSnapshot]
+  }
+
+  trait ProcessCPUMetricsListenerFixture {
+    def subscribeToMetrics(): TestProbe = {
+      val metricsListener = TestProbe()
+      Kamon(Metrics).subscribe(ProcessCPUMetrics, "*", metricsListener.ref, permanently = true)
+      // Wait for one empty snapshot before proceeding to the test.
+      metricsListener.expectMsgType[TickMetricSnapshot]
+      metricsListener
+    }
+  }
+}