fey-core/src/main/scala/org/apache/iota/fey/GlobalPerformer.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.iota.fey

import akka.actor.SupervisorStrategy.Restart
import akka.actor.{Actor, ActorLogging, ActorRef, OneForOneStrategy, Props, Terminated}
import akka.routing._
import play.api.libs.json.JsObject

import scala.collection.mutable.HashMap
import scala.concurrent.duration._

protected class GlobalPerformer(val orchestrationID: String,
                                val orchestrationName: String,
                                val globalPerformers: List[JsObject],
                                val ensemblesSpec :  List[JsObject]) extends Actor with ActorLogging{

  val monitoring_actor = FEY_MONITOR.actorRef
  var global_metadata: Map[String, Performer] = Map.empty[String, Performer]

  override def receive: Receive = {

    case GlobalPerformer.PRINT_GLOBAL =>
      context.actorSelection(s"*") ! FeyGenericActor.PRINT_PATH

    case Terminated(actor) =>
      monitoring_actor  ! Monitor.TERMINATE(actor.path.toString, Utils.getTimestamp)
      log.error(s"DEAD Global Performers ${actor.path.name}")
      context.children.foreach{ child =>
        context.unwatch(child)
        context.stop(child)
      }
      throw new RestartGlobalPerformers(s"DEAD Global Performer ${actor.path.name}")

    case GetRoutees => //Discard

    case x => log.warning(s"Message $x not treated by Global Performers")
  }

  /**
    * If any of the global performer dies, it tries to restart it.
    * If we could not be restarted, then the terminated message will be received
    * and Global Performer is going to throw an Exception to its orchestration
    * asking it to Restart all the entire orchestration. The restart will then stop all of its
    * children when call the preStart.
    */
  override val supervisorStrategy =
  OneForOneStrategy(maxNrOfRetries = 3, withinTimeRange = 1 minute) {
    case e: Exception => Restart
  }

  /**
    * Uses the json spec to create the performers
    */
  override def preStart() : Unit = {

    monitoring_actor ! Monitor.START(Utils.getTimestamp)

    global_metadata = Ensemble.extractPerformers(globalPerformers)

    createGlobalPerformers()

  }

  override def postStop() : Unit = {
    monitoring_actor  ! Monitor.STOP(Utils.getTimestamp)
  }

  override def postRestart(reason: Throwable): Unit = {
    monitoring_actor  ! Monitor.RESTART(reason, Utils.getTimestamp)
    preStart()
  }

  private def createGlobalPerformers() = {
    try {
      global_metadata.foreach((global_performer) => {
        createFeyActor(global_performer._1, global_performer._2)
      })
      context.parent ! Orchestration.CREATE_ENSEMBLES(ensemblesSpec)
    } catch {
      /* if the creation fails, it will stop the orchestration */
      case e: Exception =>
        log.error(e,"During Global Manager creation")
        throw new RestartGlobalPerformers("Could not create global performer")
    }
  }

  private def createFeyActor(performerID: String, performerInfo: Performer) = {
    val actor: ActorRef = {
      val actorProps = getPerformer(performerInfo)
      if (performerInfo.autoScale) {

        val resizer = DefaultResizer(lowerBound = performerInfo.lowerBound, upperBound = performerInfo.upperBound,
          messagesPerResize = CONFIG.MESSAGES_PER_RESIZE, backoffThreshold = performerInfo.backoffThreshold, backoffRate = 0.1)

        val strategy =
          if (performerInfo.isRoundRobin) {
            log.info(s"Using Round Robin for performer ${performerID}")
            RoundRobinPool(1, Some(resizer))
          } else {
            log.info(s"Using Smallest mailbox for performer ${performerID}")
            SmallestMailboxPool(1, Some(resizer))
          }

        context.actorOf(strategy.props(actorProps), name = performerID)
      } else {
        context.actorOf(actorProps, name = performerID)
      }
    }

    context.watch(actor)
    GlobalPerformer.activeGlobalPerformers.get(orchestrationID) match {
      case Some(globals) => GlobalPerformer.activeGlobalPerformers.put(orchestrationID, (globals ++ Map(performerID -> actor)))
      case None => GlobalPerformer.activeGlobalPerformers.put(orchestrationID, Map(performerID -> actor))
    }
  }

  /**
    * Creates actor props based on JSON configuration
    *
    * @param performerInfo Performer object
    * @return Props of actor based on JSON config
    */
  private def getPerformer(performerInfo: Performer): Props = {
    var clazz:Option[Class[FeyGenericActor]] = None

    Utils.loadedJars.synchronized {
      clazz = Some(loadClazzFromJar(performerInfo.classPath, s"${performerInfo.jarLocation}/${performerInfo.jarName}", performerInfo.jarName))
    }

    if(clazz.isDefined) {
      val dispatcher = if (performerInfo.dispatcher != "") s"fey-custom-dispatchers.${performerInfo.dispatcher}" else ""

      val actorProps = Props(clazz.get,
        performerInfo.parameters, performerInfo.backoff, Map.empty, performerInfo.schedule, orchestrationName, orchestrationID, performerInfo.autoScale)

      // dispatcher has higher priority than controlAware. That means that if both are defined
      // then the custom dispatcher will be used
      if (dispatcher != "") {
        log.info(s"Using dispatcher: $dispatcher")
        actorProps.withDispatcher(dispatcher)
      }
      else if (performerInfo.controlAware) {
        actorProps.withDispatcher(CONFIG.CONTROL_AWARE_MAILBOX)
      } else {
        actorProps
      }
    }else{
      log.error(s"Could not load class for performer ${performerInfo.uid}")
      throw new ClassNotFoundException(s"${performerInfo.jarName} -- ${performerInfo.jarLocation}")
    }
  }

  /**
    * Load a clazz instance of FeyGenericActor from a jar
    *
    * @param classPath class path
    * @param jarLocation Full path where to load the jar from
    * @return clazz instance of FeyGenericActor
    */
  private def loadClazzFromJar(classPath: String, jarLocation: String, jarName: String):Class[FeyGenericActor] = {
    try {
      Utils.loadActorClassFromJar(jarLocation,classPath,jarName)
    }catch {
      case e: Exception =>
        log.error(e,s"Could not load class $classPath from jar $jarLocation. Please, check the Jar repository path as well the jar name")
        throw e
    }
  }

}

object GlobalPerformer{

  val activeGlobalPerformers:HashMap[String, Map[String, ActorRef]] = HashMap.empty[String, Map[String, ActorRef]]

  case object PRINT_GLOBAL
}