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

This example Akka source code file (ClusterSettings.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, boolean, cluster, collection, concurrent, config, duration, finiteduration, int, metricsgossipinterval, minnrofmembersofrole, periodictasksinitialdelay, reducegossipdifferentviewprobability, string, time

The ClusterSettings.scala Akka example source code

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

import scala.collection.immutable
import com.typesafe.config.Config
import com.typesafe.config.ConfigObject
import scala.concurrent.duration.Duration
import java.util.concurrent.TimeUnit.MILLISECONDS
import akka.actor.Address
import akka.actor.AddressFromURIString
import akka.dispatch.Dispatchers
import akka.util.Helpers.Requiring
import akka.util.Helpers.ConfigOps
import scala.concurrent.duration.FiniteDuration
import akka.japi.Util.immutableSeq

final class ClusterSettings(val config: Config, val systemName: String) {

  private val cc = config.getConfig("akka.cluster")

  val LogInfo: Boolean = cc.getBoolean("log-info")
  val FailureDetectorConfig: Config = cc.getConfig("failure-detector")
  val FailureDetectorImplementationClass: String = FailureDetectorConfig.getString("implementation-class")
  val HeartbeatInterval: FiniteDuration = {
    FailureDetectorConfig.getMillisDuration("heartbeat-interval")
  } requiring (_ > Duration.Zero, "failure-detector.heartbeat-interval must be > 0")
  val HeartbeatExpectedResponseAfter: FiniteDuration = {
    FailureDetectorConfig.getMillisDuration("expected-response-after")
  } requiring (_ > Duration.Zero, "failure-detector.expected-response-after > 0")
  val MonitoredByNrOfMembers: Int = {
    FailureDetectorConfig.getInt("monitored-by-nr-of-members")
  } requiring (_ > 0, "failure-detector.monitored-by-nr-of-members must be > 0")

  val SeedNodes: immutable.IndexedSeq[Address] =
    immutableSeq(cc.getStringList("seed-nodes")).map { case AddressFromURIString(addr) ⇒ addr }.toVector
  val SeedNodeTimeout: FiniteDuration = cc.getMillisDuration("seed-node-timeout")
  val RetryUnsuccessfulJoinAfter: Duration = {
    val key = "retry-unsuccessful-join-after"
    cc.getString(key).toLowerCase match {
      case "off" ⇒ Duration.Undefined
      case _     ⇒ cc.getMillisDuration(key) requiring (_ > Duration.Zero, key + " > 0s, or off")
    }
  }
  val PeriodicTasksInitialDelay: FiniteDuration = cc.getMillisDuration("periodic-tasks-initial-delay")
  val GossipInterval: FiniteDuration = cc.getMillisDuration("gossip-interval")
  val GossipTimeToLive: FiniteDuration = {
    cc.getMillisDuration("gossip-time-to-live")
  } requiring (_ > Duration.Zero, "gossip-time-to-live must be > 0")
  val LeaderActionsInterval: FiniteDuration = cc.getMillisDuration("leader-actions-interval")
  val UnreachableNodesReaperInterval: FiniteDuration = cc.getMillisDuration("unreachable-nodes-reaper-interval")
  val PublishStatsInterval: Duration = {
    val key = "publish-stats-interval"
    cc.getString(key).toLowerCase match {
      case "off" ⇒ Duration.Undefined
      case _     ⇒ cc.getMillisDuration(key) requiring (_ >= Duration.Zero, key + " >= 0s, or off")
    }
  }

  val AutoDownUnreachableAfter: Duration = {
    val key = "auto-down-unreachable-after"
    cc.getString(key).toLowerCase match {
      case "off" ⇒ Duration.Undefined
      case _     ⇒ cc.getMillisDuration(key) requiring (_ >= Duration.Zero, key + " >= 0s, or off")
    }
  }

  val Roles: Set[String] = immutableSeq(cc.getStringList("roles")).toSet
  val MinNrOfMembers: Int = {
    cc.getInt("min-nr-of-members")
  } requiring (_ > 0, "min-nr-of-members must be > 0")
  val MinNrOfMembersOfRole: Map[String, Int] = {
    import scala.collection.JavaConverters._
    cc.getConfig("role").root.asScala.collect {
      case (key, value: ConfigObject) ⇒ (key -> value.toConfig.getInt("min-nr-of-members"))
    }.toMap
  }
  val JmxEnabled: Boolean = cc.getBoolean("jmx.enabled")
  val UseDispatcher: String = cc.getString("use-dispatcher") match {
    case "" ⇒ Dispatchers.DefaultDispatcherId
    case id ⇒ id
  }
  val GossipDifferentViewProbability: Double = cc.getDouble("gossip-different-view-probability")
  val ReduceGossipDifferentViewProbability: Int = cc.getInt("reduce-gossip-different-view-probability")
  val SchedulerTickDuration: FiniteDuration = cc.getMillisDuration("scheduler.tick-duration")
  val SchedulerTicksPerWheel: Int = cc.getInt("scheduler.ticks-per-wheel")
  val MetricsEnabled: Boolean = cc.getBoolean("metrics.enabled")
  val MetricsCollectorClass: String = cc.getString("metrics.collector-class")
  val MetricsInterval: FiniteDuration = {
    cc.getMillisDuration("metrics.collect-interval")
  } requiring (_ > Duration.Zero, "metrics.collect-interval must be > 0")
  val MetricsGossipInterval: FiniteDuration = cc.getMillisDuration("metrics.gossip-interval")
  val MetricsMovingAverageHalfLife: FiniteDuration = {
    cc.getMillisDuration("metrics.moving-average-half-life")
  } requiring (_ > Duration.Zero, "metrics.moving-average-half-life must be > 0")

}