Simplify test + make access to akka frame size more modular

core/src/main/scala/org/apache/spark/MapOutputTracker.scala

@@ -37,7 +37,7 @@ private[spark] case object StopMapOutputTracker extends MapOutputTrackerMessage
 
 private[spark] class MapOutputTrackerMasterActor(tracker: MapOutputTrackerMaster, conf: SparkConf)
   extends Actor with Logging {
-  val maxAkkaFrameSize = conf.getInt("spark.akka.frameSize", 10) * 1024 * 1024 // MB
+  val maxAkkaFrameSize = AkkaUtils.maxFrameSize(conf) * 1024 * 1024 // MB
 
   def receive = {
     case GetMapOutputStatuses(shuffleId: Int) =>

core/src/main/scala/org/apache/spark/util/AkkaUtils.scala

@@ -49,7 +49,7 @@ private[spark] object AkkaUtils extends Logging {
 
     val akkaTimeout = conf.getInt("spark.akka.timeout", 100)
 
-    val akkaFrameSize = conf.getInt("spark.akka.frameSize", 10)
+    val akkaFrameSize = maxFrameSize(conf)
     val akkaLogLifecycleEvents = conf.getBoolean("spark.akka.logLifecycleEvents", false)
     val lifecycleEvents = if (akkaLogLifecycleEvents) "on" else "off"
     if (!akkaLogLifecycleEvents) {
@@ -121,4 +121,9 @@ private[spark] object AkkaUtils extends Logging {
   def lookupTimeout(conf: SparkConf): FiniteDuration = {
     Duration.create(conf.get("spark.akka.lookupTimeout", "30").toLong, "seconds")
   }
+
+  /** Returns the default max frame size for Akka messages in MB. */
+  def maxFrameSize(conf: SparkConf): Int = {
+    conf.getInt("spark.akka.frameSize", 10)
+  }
 }

core/src/test/scala/org/apache/spark/MapOutputTrackerSuite.scala

@@ -20,6 +20,7 @@ package org.apache.spark
 import scala.concurrent.Await
 
 import akka.actor._
+import akka.testkit.TestActorRef
 import org.scalatest.FunSuite
 
 import org.apache.spark.scheduler.MapStatus
@@ -100,7 +101,25 @@ class MapOutputTrackerSuite extends FunSuite with LocalSparkContext {
   }
 
   test("remote fetch") {
-    val (masterTracker, slaveTracker) = setUpMasterSlaveSystem(conf)
+    val hostname = "localhost"
+    val (actorSystem, boundPort) = AkkaUtils.createActorSystem("spark", hostname, 0, conf = conf,
+      securityManager = new SecurityManager(conf))
+
+    // Will be cleared by LocalSparkContext
+    System.setProperty("spark.driver.port", boundPort.toString)
+
+    val masterTracker = new MapOutputTrackerMaster(conf)
+    masterTracker.trackerActor = actorSystem.actorOf(
+      Props(new MapOutputTrackerMasterActor(masterTracker, conf)), "MapOutputTracker")
+
+    val (slaveSystem, _) = AkkaUtils.createActorSystem("spark-slave", hostname, 0, conf = conf,
+      securityManager = new SecurityManager(conf))
+    val slaveTracker = new MapOutputTracker(conf)
+    val selection = slaveSystem.actorSelection(
+      s"akka.tcp://spark@localhost:$boundPort/user/MapOutputTracker")
+    val timeout = AkkaUtils.lookupTimeout(conf)
+    slaveTracker.trackerActor = Await.result(selection.resolveOne(timeout), timeout)
+
     masterTracker.registerShuffle(10, 1)
     masterTracker.incrementEpoch()
     slaveTracker.updateEpoch(masterTracker.getEpoch)
@@ -113,7 +132,7 @@ class MapOutputTrackerSuite extends FunSuite with LocalSparkContext {
     masterTracker.incrementEpoch()
     slaveTracker.updateEpoch(masterTracker.getEpoch)
     assert(slaveTracker.getServerStatuses(10, 0).toSeq ===
-           Seq((BlockManagerId("a", "hostA", 1000, 0), size1000)))
+      Seq((BlockManagerId("a", "hostA", 1000, 0), size1000)))
 
     masterTracker.unregisterMapOutput(10, 0, BlockManagerId("a", "hostA", 1000, 0))
     masterTracker.incrementEpoch()
@@ -128,42 +147,25 @@ class MapOutputTrackerSuite extends FunSuite with LocalSparkContext {
     val newConf = new SparkConf
     newConf.set("spark.akka.frameSize", "1")
     newConf.set("spark.akka.askTimeout", "1") // Fail fast
-    val (masterTracker, slaveTracker) = setUpMasterSlaveSystem(newConf)
+
+    val masterTracker = new MapOutputTrackerMaster(conf)
+    val actorSystem = ActorSystem("test")
+    val actorRef = TestActorRef[MapOutputTrackerMasterActor](
+      new MapOutputTrackerMasterActor(masterTracker, newConf))(actorSystem)
+    val masterActor = actorRef.underlyingActor
 
     // Frame size should be ~123B, and no exception should be thrown
     masterTracker.registerShuffle(10, 1)
     masterTracker.registerMapOutput(10, 0, new MapStatus(
       BlockManagerId("88", "mph", 1000, 0), Array.fill[Byte](10)(0)))
-    slaveTracker.getServerStatuses(10, 0)
+    masterActor.receive(GetMapOutputStatuses(10))
 
     // Frame size should be ~1.1MB, and MapOutputTrackerMasterActor should throw exception
     masterTracker.registerShuffle(20, 100)
     (0 until 100).foreach { i =>
       masterTracker.registerMapOutput(20, i, new MapStatus(
         BlockManagerId("999", "mps", 1000, 0), Array.fill[Byte](4000000)(0)))
     }
-    intercept[SparkException] { slaveTracker.getServerStatuses(20, 0) }
-  }
-
-  private def setUpMasterSlaveSystem(conf: SparkConf) = {
-    val hostname = "localhost"
-    val (actorSystem, boundPort) = AkkaUtils.createActorSystem("spark", hostname, 0, conf = conf,
-      securityManager = new SecurityManager(conf))
-
-    // Will be cleared by LocalSparkContext
-    System.setProperty("spark.driver.port", boundPort.toString)
-
-    val masterTracker = new MapOutputTrackerMaster(conf)
-    masterTracker.trackerActor = actorSystem.actorOf(
-      Props(new MapOutputTrackerMasterActor(masterTracker, conf)), "MapOutputTracker")
-
-    val (slaveSystem, _) = AkkaUtils.createActorSystem("spark-slave", hostname, 0, conf = conf,
-      securityManager = new SecurityManager(conf))
-    val slaveTracker = new MapOutputTracker(conf)
-    val selection = slaveSystem.actorSelection(
-      s"akka.tcp://spark@localhost:$boundPort/user/MapOutputTracker")
-    val timeout = AkkaUtils.lookupTimeout(conf)
-    slaveTracker.trackerActor = Await.result(selection.resolveOne(timeout), timeout)
-    (masterTracker, slaveTracker)
+    intercept[SparkException] { masterActor.receive(GetMapOutputStatuses(20)) }
   }
 }