/*
* =========================================================================================
* 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.statsd
import akka.actor.{ActorSystem, Props, ActorRef, Actor}
import akka.io.{ Udp, IO }
import java.net.InetSocketAddress
import akka.util.ByteString
import kamon.Kamon
import kamon.metrics.Subscriptions.TickMetricSnapshot
import kamon.metrics.MetricSnapshot.Measurement
import kamon.metrics.InstrumentTypes.{Counter, Gauge, Histogram, InstrumentType}
class StatsDMetricsSender extends Actor with UdpExtensionProvider {
import context.system
val statsDExtension = Kamon(StatsD)
val remote = new InetSocketAddress(statsDExtension.hostname, statsDExtension.port)
val metricKeyGenerator = new SimpleMetricKeyGenerator(context.system.settings.config)
udpExtension ! Udp.SimpleSender
def receive = {
case Udp.SimpleSenderReady ⇒
context.become(ready(sender))
}
def ready(udpSender: ActorRef): Receive = {
case tick: TickMetricSnapshot => writeMetricsToRemote(tick, udpSender)
}
def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
val dataBuilder = new MetricDataPacketBuilder(statsDExtension.maxPacketSize, udpSender, remote)
for((groupIdentity, groupSnapshot) <- tick.metrics;
(metricIdentity, metricSnapshot) <- groupSnapshot.metrics) {
val key = ByteString(metricKeyGenerator.generateKey(groupIdentity, metricIdentity))
for(measurement <- metricSnapshot.measurements) {
val measurementData = encodeMeasurement(measurement, metricSnapshot.instrumentType)
dataBuilder.appendMeasurement(key, measurementData)
}
}
dataBuilder.flush()
}
def encodeMeasurement(measurement: Measurement, instrumentType: InstrumentType): ByteString = {
def statsDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): ByteString =
ByteString(value + "|" + metricType + (if (samplingRate != 1D) "|@" + samplingRate else ""))
instrumentType match {
case Histogram => statsDMetricFormat(measurement.value.toString, "ms", (1D / measurement.count))
case Gauge => statsDMetricFormat(measurement.value.toString, "g")
case Counter => ByteString.empty // TODO: Need to decide how to report counters, when we have them!
}
}
}
object StatsDMetricsSender {
def props: Props = Props[StatsDMetricsSender]
}
trait UdpExtensionProvider {
def udpExtension(implicit system: ActorSystem): ActorRef = IO(Udp)
}
class MetricDataPacketBuilder(maxPacketSize: Int, udpSender: ActorRef, remote: InetSocketAddress) {
val metricSeparator = ByteString("\n")
val measurementSeparator = ByteString(":")
var lastKey= ByteString.empty
var buffer = ByteString.empty
def appendMeasurement(key: ByteString, measurementData: ByteString): Unit = {
val appendData =
if(key == lastKey)
measurementSeparator ++ measurementData
else {
lastKey = key
val keySeparator = if(buffer.length == 0) ByteString.empty else metricSeparator
keySeparator ++ key ++ measurementSeparator ++ measurementData
}
if(buffer.length + appendData.length >= maxPacketSize) {
flushToUDP(buffer)
buffer = appendData
} else
buffer = buffer ++ appendData
}
private def flushToUDP(bytes: ByteString): Unit = udpSender ! Udp.Send(bytes, remote)
def flush(): Unit = {
flushToUDP(buffer)
buffer = ByteString.empty
}
}