Akka/Scala example source code file (RemoteMetricsExtension.scala)

This example Akka source code file (RemoteMetricsExtension.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, akka, any, concurrenthashmap, event, extendedactorsystem, extensionid, int, remote, remotemetrics, remotemetricsextension, remotemetricsoff, remotemetricson, route, routing, unit

The RemoteMetricsExtension.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.remote

import java.util.concurrent.ConcurrentHashMap
import scala.annotation.tailrec
import akka.actor.ActorSelectionMessage
import akka.actor.ActorSystem
import akka.actor.ExtendedActorSystem
import akka.actor.Extension
import akka.actor.ExtensionId
import akka.actor.ExtensionIdProvider
import akka.event.Logging
import akka.routing.RouterEnvelope

/**
 * INTERNAL API
 * Extension that keeps track of remote metrics, such
 * as max size of different message types.
 */
private[akka] object RemoteMetricsExtension extends ExtensionId[RemoteMetrics] with ExtensionIdProvider {
  override def get(system: ActorSystem): RemoteMetrics = super.get(system)

  override def lookup = RemoteMetricsExtension

  override def createExtension(system: ExtendedActorSystem): RemoteMetrics =
    if (system.settings.config.getString("akka.remote.log-frame-size-exceeding").toLowerCase == "off")
      new RemoteMetricsOff
    else
      new RemoteMetricsOn(system)
}

/**
 * INTERNAL API
 */
private[akka] trait RemoteMetrics extends Extension {
  /**
   * Logging of the size of different message types.
   * Maximum detected size per message type is logged once, with
   * and increase threshold of 10%.
   */
  def logPayloadBytes(msg: Any, payloadBytes: Int): Unit
}

/**
 * INTERNAL API
 */
private[akka] class RemoteMetricsOff extends RemoteMetrics {
  override def logPayloadBytes(msg: Any, payloadBytes: Int): Unit = ()
}

/**
 * INTERNAL API
 */
private[akka] class RemoteMetricsOn(system: ExtendedActorSystem) extends RemoteMetrics {

  private val logFrameSizeExceeding: Int = system.settings.config.getBytes(
    "akka.remote.log-frame-size-exceeding").toInt
  private val log = Logging(system, this.getClass)
  private val maxPayloadBytes: ConcurrentHashMap[Class[_], Integer] = new ConcurrentHashMap

  override def logPayloadBytes(msg: Any, payloadBytes: Int): Unit =
    if (payloadBytes >= logFrameSizeExceeding) {
      val clazz = msg match {
        case x: ActorSelectionMessage ⇒ x.msg.getClass
        case x: RouterEnvelope        ⇒ x.message.getClass
        case _                        ⇒ msg.getClass
      }

      // 10% threshold until next log
      def newMax = (payloadBytes * 1.1).toInt

      @tailrec def check(): Unit = {
        val max = maxPayloadBytes.get(clazz)
        if (max eq null) {
          if (maxPayloadBytes.putIfAbsent(clazz, newMax) eq null)
            log.info("Payload size for [{}] is [{}] bytes", clazz.getName, payloadBytes)
          else check()
        } else if (payloadBytes > max) {
          if (maxPayloadBytes.replace(clazz, max, newMax))
            log.info("New maximum payload size for [{}] is [{}] bytes", clazz.getName, payloadBytes)
          else check()
        }
      }
      check()
    }
}