+ datadog: more tests and support for multiple metrics in the same package

4 files changed, 100 insertions, 34 deletions

diff --git a/kamon-datadog/src/main/resources/reference.conf b/kamon-datadog/src/main/resources/reference.conf
index c7400f53..231eaf7d 100644
--- a/kamon-datadog/src/main/resources/reference.conf
+++ b/kamon-datadog/src/main/resources/reference.conf
@@ -13,6 +13,9 @@ kamon {
     # kamon.metrics.tick-interval setting.
     flush-interval = 1 second
 
+    # Max packet size for UDP metrics data sent to Datadog.
+    max-packet-size = 1024 bytes
+
     # Subscription patterns used to select which metrics will be pushed to Datadog. Note that first, metrics
     # collection for your desired entities must be activated under the kamon.metrics.filters settings.
     includes {
diff --git a/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala b/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
index a323af78..15d5d3fe 100644
--- a/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
+++ b/kamon-datadog/src/main/scala/kamon/datadog/Datadog.scala
@@ -44,6 +44,7 @@ class DatadogExtension(system: ExtendedActorSystem) extends Kamon.Extension {
 
   val datadogHost = new InetSocketAddress(datadogConfig.getString("hostname"), datadogConfig.getInt("port"))
   val flushInterval = datadogConfig.getDuration("flush-interval", MILLISECONDS)
+  val maxPacketSizeInBytes = datadogConfig.getBytes("max-packet-size")
   val tickInterval = system.settings.config.getDuration("kamon.metrics.tick-interval", MILLISECONDS)
 
   val datadogMetricsListener = buildMetricsListener(tickInterval, flushInterval)
@@ -69,7 +70,7 @@ class DatadogExtension(system: ExtendedActorSystem) extends Kamon.Extension {
   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), "datadog-metrics-sender")
+    val metricsTranslator = 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
diff --git a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
index ec603b39..de4dc140 100644
--- a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
+++ b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
@@ -16,17 +16,18 @@
 
 package kamon.datadog
 
-import akka.actor.{ ActorSystem, Props, ActorRef, Actor }
-import akka.io.{ Udp, IO }
+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.metrics.InstrumentTypes.{Counter, Gauge, Histogram, InstrumentType}
 import java.text.DecimalFormat
-import kamon.metrics.{ MetricIdentity, MetricGroupIdentity }
+import kamon.metrics.{MetricIdentity, MetricGroupIdentity}
+
+class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long) extends Actor with UdpExtensionProvider {
 
-class DatadogMetricsSender(remote: InetSocketAddress) extends Actor with UdpExtensionProvider {
   import context.system
 
   val appName = context.system.settings.config.getString("kamon.datadog.application-name")
@@ -45,53 +46,82 @@ class DatadogMetricsSender(remote: InetSocketAddress) extends Actor with UdpExte
   }
 
   def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
-    def flushToUDP(data: String): Unit = udpSender ! Udp.Send(ByteString(data), remote)
+    val dataBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
 
-    for (
+    for {
       (groupIdentity, groupSnapshot) ← tick.metrics;
       (metricIdentity, metricSnapshot) ← groupSnapshot.metrics
-    ) {
+    } {
+
+      val key = buildMetricName(groupIdentity, metricIdentity)
 
       for (measurement ← metricSnapshot.measurements) {
         val measurementData = formatMeasurement(groupIdentity, metricIdentity, measurement, metricSnapshot.instrumentType)
-        flushToUDP(measurementData)
+        dataBuilder.appendMeasurement(key, measurementData)
       }
     }
+    dataBuilder.flush()
   }
 
   def formatMeasurement(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity, measurement: Measurement,
                         instrumentType: InstrumentType): String = {
 
-    StringBuilder.newBuilder
-      .append(buildMetricName(groupIdentity, metricIdentity))
-      .append(":")
-      .append(buildMeasurementData(measurement, instrumentType))
+    StringBuilder.newBuilder.append(buildMeasurementData(measurement, instrumentType))
       .append(buildIdentificationTag(groupIdentity, metricIdentity))
       .result()
   }
 
   def buildMeasurementData(measurement: Measurement, instrumentType: InstrumentType): String = {
     def dataDogDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): String =
-      value + "|" + metricType + (if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")
+      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")
+      case Gauge ⇒ dataDogDMetricFormat(measurement.value.toString, "g")
+      case Counter ⇒ dataDogDMetricFormat(measurement.count.toString, "c")
     }
   }
 
   def buildMetricName(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
-    appName + "." + groupIdentity.category.name + "." + metricIdentity.name
+    s"$appName.${groupIdentity.category.name}.${metricIdentity.name}"
 
   def buildIdentificationTag(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
-    "|#" + groupIdentity.category.name + ":" + groupIdentity.name
+    s"|#${groupIdentity.category.name}:${groupIdentity.name}"
 }
 
 object DatadogMetricsSender {
-  def props(remote: InetSocketAddress): Props = Props(new DatadogMetricsSender(remote))
+  def props(remote: InetSocketAddress, maxPacketSize: Long): Props = Props(new DatadogMetricsSender(remote, maxPacketSize))
 }
 
 trait UdpExtensionProvider {
   def udpExtension(implicit system: ActorSystem): ActorRef = IO(Udp)
 }
+
+class MetricDataPacketBuilder(maxPacketSizeInBytes: Long, udpSender: ActorRef, remote: InetSocketAddress) {
+  val metricSeparator = "\n"
+  val measurementSeparator = ":"
+  var lastKey = ""
+  var buffer = new StringBuilder()
+
+  def appendMeasurement(key: String, measurementData: String): Unit = {
+    val data = key + measurementSeparator + measurementData
+
+    if (fitsOnBuffer(metricSeparator + data)) {
+      val mSeparator = if (buffer.length > 0) metricSeparator else ""
+      buffer.append(mSeparator).append(data)
+    } else {
+      flushToUDP(buffer.toString())
+      buffer.clear()
+      buffer.append(data)
+    }
+  }
+
+  def fitsOnBuffer(data: String): Boolean = (buffer.length + data.length) <= maxPacketSizeInBytes
+
+  private def flushToUDP(data: String): Unit = udpSender ! Udp.Send(ByteString(data), remote)
+
+  def flush(): Unit = {
+    flushToUDP(buffer.toString)
+    buffer.clear()
+  }
+}
diff --git a/kamon-datadog/src/test/scala/kamon/datadog/DatadogMetricSenderSpec.scala b/kamon-datadog/src/test/scala/kamon/datadog/DatadogMetricSenderSpec.scala
index c649a044..6a7191a1 100644
--- a/kamon-datadog/src/test/scala/kamon/datadog/DatadogMetricSenderSpec.scala
+++ b/kamon-datadog/src/test/scala/kamon/datadog/DatadogMetricSenderSpec.scala
@@ -16,10 +16,10 @@
 
 package kamon.datadog
 
-import akka.testkit.{ TestKitBase, TestProbe }
-import akka.actor.{ Props, ActorRef, ActorSystem }
+import akka.testkit.{TestKitBase, TestProbe}
+import akka.actor.{Props, ActorRef, ActorSystem}
 import kamon.metrics.instruments.CounterRecorder
-import org.scalatest.{ Matchers, WordSpecLike }
+import org.scalatest.{Matchers, WordSpecLike}
 import kamon.metrics._
 import akka.io.Udp
 import org.HdrHistogram.HdrRecorder
@@ -56,20 +56,52 @@ class DatadogMetricSenderSpec extends TestKitBase with WordSpecLike with Matcher
       data.utf8String should be(s"kamon.actor.processing-time:10|ms|@0.5|#actor:user/kamon")
     }
 
-    "send only one packet per measurement" in new UdpListenerFixture {
+    "flush the packet when the max-packet-size is reached" in new UdpListenerFixture {
       val testMetricName = "processing-time"
-      val testRecorder = HdrRecorder(1000L, 2, Scale.Unit)
-      testRecorder.record(10L)
-      testRecorder.record(10L)
-      testRecorder.record(20L)
+      val testRecorder = HdrRecorder(testMaxPacketSize, 3, Scale.Unit)
+
+      var bytes = 0
+      var level = 0
+
+      while (bytes <= testMaxPacketSize) {
+        level += 1
+        testRecorder.record(level)
+        bytes += s"kamon.actor.$testMetricName:$level|ms|#actor:user/kamon".length
+      }
 
       val udp = setup(Map(testMetricName -> testRecorder.collect()))
+      udp.expectMsgType[Udp.Send]// let the first flush pass
+
+      val Udp.Send(data, _, _) = udp.expectMsgType[Udp.Send]
+      data.utf8String should be(s"kamon.actor.$testMetricName:$level|ms|#actor:user/kamon")
+    }
 
-      val Udp.Send(data1, _, _) = udp.expectMsgType[Udp.Send]
-      data1.utf8String should be(s"kamon.actor.processing-time:10|ms|@0.5|#actor:user/kamon")
+    "render multiple keys in the same packet using newline as separator" in new UdpListenerFixture {
+      val firstTestMetricName = "processing-time-1"
+      val secondTestMetricName = "processing-time-2"
+      val thirdTestMetricName = "counter"
 
-      val Udp.Send(data2, _, _) = udp.expectMsgType[Udp.Send]
-      data2.utf8String should be(s"kamon.actor.processing-time:20|ms|#actor:user/kamon")
+      val firstTestRecorder = HdrRecorder(1000L, 2, Scale.Unit)
+      val secondTestRecorder = HdrRecorder(1000L, 2, Scale.Unit)
+      val thirdTestRecorder = CounterRecorder()
+
+      firstTestRecorder.record(10L)
+      firstTestRecorder.record(10L)
+
+      secondTestRecorder.record(21L)
+
+      thirdTestRecorder.record(1L)
+      thirdTestRecorder.record(1L)
+      thirdTestRecorder.record(1L)
+      thirdTestRecorder.record(1L)
+
+      val udp = setup(Map(
+        firstTestMetricName -> firstTestRecorder.collect(),
+        secondTestMetricName -> secondTestRecorder.collect(),
+        thirdTestMetricName -> thirdTestRecorder.collect()))
+      val Udp.Send(data, _, _) = udp.expectMsgType[Udp.Send]
+
+      data.utf8String should be("kamon.actor.processing-time-1:10|ms|@0.5|#actor:user/kamon\nkamon.actor.processing-time-2:21|ms|#actor:user/kamon\nkamon.actor.counter:4|c|#actor:user/kamon")
     }
   }
 
@@ -79,7 +111,7 @@ class DatadogMetricSenderSpec extends TestKitBase with WordSpecLike with Matcher
 
     def setup(metrics: Map[String, MetricSnapshotLike]): TestProbe = {
       val udp = TestProbe()
-      val metricsSender = system.actorOf(Props(new DatadogMetricsSender(new InetSocketAddress(localhostName, 0)) {
+      val metricsSender = system.actorOf(Props(new DatadogMetricsSender(new InetSocketAddress(localhostName, 0), testMaxPacketSize) {
         override def udpExtension(implicit system: ActorSystem): ActorRef = udp.ref
       }))
 
@@ -107,8 +139,8 @@ class DatadogMetricSenderSpec extends TestKitBase with WordSpecLike with Matcher
       metricsSender ! TickMetricSnapshot(0, 0, Map(testGroupIdentity -> new MetricGroupSnapshot {
         val metrics: Map[MetricIdentity, MetricSnapshotLike] = testMetrics.toMap
       }))
-
       udp
     }
   }
+
 }