Merge branch 'master' into release-0.2

Conflicts:
	kamon-core/src/main/scala/kamon/metrics/Subscriptions.scala
	kamon-core/src/test/scala/kamon/instrumentation/akka/ActorCellInstrumentationSpec.scala
	kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
	kamon-play/src/main/scala/kamon/play/instrumentation/WSInstrumentation.scala
	kamon-play/src/test/scala/kamon/play/RequestInstrumentationSpec.scala
	kamon-play/src/test/scala/kamon/play/WSInstrumentationSpec.scala
	kamon-playground/src/main/scala/test/SimpleRequestProcessor.scala
	kamon-statsd/src/main/scala/kamon/statsd/StatsD.scala
	project/Projects.scala
	version.sbt

2 files changed, 42 insertions, 28 deletions

diff --git a/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala b/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
index 1eb2e8a6..63557781 100644
--- a/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
+++ b/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
@@ -18,7 +18,9 @@ package kamon.datadog
 
 import akka.actor._
 import kamon.Kamon
+import kamon.metric._
 import kamon.metrics._
+import kamon.metrics.CPUMetrics
 import scala.concurrent.duration._
 import scala.collection.JavaConverters._
 import akka.event.Logging
@@ -64,15 +66,23 @@ class DatadogExtension(system: ExtendedActorSystem) extends Kamon.Extension {
     Kamon(Metrics)(system).subscribe(DispatcherMetrics, dispatcherPathPattern, datadogMetricsListener, permanently = true)
   }
 
+  // Subscribe to SystemMetrics
+  val includeSystemMetrics = datadogConfig.getBoolean("report-system-metrics")
+  if (includeSystemMetrics) {
+    List(CPUMetrics, ProcessCPUMetrics, MemoryMetrics, NetworkMetrics, GCMetrics, HeapMetrics) foreach { metric ⇒
+      Kamon(Metrics)(system).subscribe(metric, "*", datadogMetricsListener, permanently = true)
+    }
+  }
+
   def buildMetricsListener(tickInterval: Long, flushInterval: Long): ActorRef = {
     assert(flushInterval >= tickInterval, "Datadog flush-interval needs to be equal or greater to the tick-interval")
 
-    val metricsTranslator = system.actorOf(DatadogMetricsSender.props(datadogHost, maxPacketSizeInBytes), "datadog-metrics-sender")
+    val metricsSender = system.actorOf(DatadogMetricsSender.props(datadogHost, maxPacketSizeInBytes), "datadog-metrics-sender")
     if (flushInterval == tickInterval) {
       // No need to buffer the metrics, let's go straight to the metrics sender.
-      metricsTranslator
+      metricsSender
     } else {
-      system.actorOf(TickMetricSnapshotBuffer.props(flushInterval.toInt.millis, metricsTranslator), "datadog-metrics-buffer")
+      system.actorOf(TickMetricSnapshotBuffer.props(flushInterval.toInt.millis, metricsSender), "datadog-metrics-buffer")
     }
   }
 }
diff --git a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
index 028e9608..0f67cc34 100644
--- a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
+++ b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
@@ -20,11 +20,10 @@ import akka.actor.{ ActorSystem, Props, ActorRef, Actor }
 import akka.io.{ Udp, IO }
 import java.net.InetSocketAddress
 import akka.util.ByteString
-import kamon.metrics.Subscriptions.TickMetricSnapshot
-import kamon.metrics.MetricSnapshot.Measurement
-import kamon.metrics.InstrumentTypes.{ Counter, Gauge, Histogram, InstrumentType }
+import kamon.metric.Subscriptions.TickMetricSnapshot
 import java.text.{ DecimalFormatSymbols, DecimalFormat }
-import kamon.metrics.{ MetricIdentity, MetricGroupIdentity }
+import kamon.metric.instrument.{ Counter, Histogram }
+import kamon.metric.{ MetricIdentity, MetricGroupIdentity }
 import java.util.Locale
 
 class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long) extends Actor with UdpExtensionProvider {
@@ -50,7 +49,7 @@ class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long
   }
 
   def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
-    val dataBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
+    val packetBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
 
     for {
       (groupIdentity, groupSnapshot) ← tick.metrics
@@ -59,38 +58,43 @@ class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long
 
       val key = buildMetricName(groupIdentity, metricIdentity)
 
-      for (measurement ← metricSnapshot.measurements) {
-        val measurementData = formatMeasurement(groupIdentity, metricIdentity, measurement, metricSnapshot.instrumentType)
-        dataBuilder.appendMeasurement(key, measurementData)
+      metricSnapshot match {
+        case hs: Histogram.Snapshot ⇒
+          hs.recordsIterator.foreach { record ⇒
+            val measurementData = formatMeasurement(groupIdentity, metricIdentity, encodeStatsDTimer(record.level, record.count))
+            packetBuilder.appendMeasurement(key, measurementData)
+
+          }
+
+        case cs: Counter.Snapshot ⇒
+          val measurementData = formatMeasurement(groupIdentity, metricIdentity, encodeStatsDCounter(cs.count))
+          packetBuilder.appendMeasurement(key, measurementData)
       }
     }
-    dataBuilder.flush()
+    packetBuilder.flush()
   }
 
-  def formatMeasurement(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity, measurement: Measurement,
-                        instrumentType: InstrumentType): String = {
-
-    StringBuilder.newBuilder.append(buildMeasurementData(measurement, instrumentType))
+  def formatMeasurement(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity, measurementData: String): String =
+    StringBuilder.newBuilder
+      .append(measurementData)
       .append(buildIdentificationTag(groupIdentity, metricIdentity))
       .result()
-  }
 
-  def buildMeasurementData(measurement: Measurement, instrumentType: InstrumentType): String = {
-    def dataDogDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): String =
-      s"$value|$metricType${(if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")}"
-
-    instrumentType match {
-      case Histogram ⇒ dataDogDMetricFormat(measurement.value.toString, "ms", (1D / measurement.count))
-      case Gauge     ⇒ dataDogDMetricFormat(measurement.value.toString, "g")
-      case Counter   ⇒ dataDogDMetricFormat(measurement.count.toString, "c")
-    }
+  def encodeStatsDTimer(level: Long, count: Long): String = {
+    val samplingRate: Double = 1D / count
+    level.toString + "|ms" + (if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")
   }
 
+  def encodeStatsDCounter(count: Long): String = count.toString + "|c"
+
   def buildMetricName(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
     s"$appName.${groupIdentity.category.name}.${metricIdentity.name}"
 
-  def buildIdentificationTag(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
-    s"|#${groupIdentity.category.name}:${groupIdentity.name}"
+  def buildIdentificationTag(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String = {
+    // Make the automatic HTTP trace names a bit more friendly
+    val normalizedEntityName = groupIdentity.name.replace(": ", ":")
+    s"|#${groupIdentity.category.name}:${normalizedEntityName}"
+  }
 }
 
 object DatadogMetricsSender {