Address review comments

core/src/main/scala/org/apache/spark/deploy/ApplicationDescription.scala

@@ -19,7 +19,7 @@ package org.apache.spark.deploy
 
 private[spark] class ApplicationDescription(
     val name: String,
-    val maxCores: Int, /* Integer.MAX_VALUE denotes an unlimited number of cores */
+    val maxCores: Option[Int],
     val memoryPerSlave: Int,
     val command: Command,
     val sparkHome: String,

core/src/main/scala/org/apache/spark/deploy/client/TestClient.scala

@@ -48,7 +48,7 @@ private[spark] object TestClient {
     val (actorSystem, port) = AkkaUtils.createActorSystem("spark", Utils.localIpAddress, 0,
       conf = new SparkConf)
     val desc = new ApplicationDescription(
-      "TestClient", 1, 512, Command("spark.deploy.client.TestExecutor", Seq(), Map()),
+      "TestClient", Some(1), 512, Command("spark.deploy.client.TestExecutor", Seq(), Map()),
       "dummy-spark-home", "ignored")
     val listener = new TestListener
     val client = new Client(actorSystem, Array(url), desc, listener, new SparkConf)

core/src/main/scala/org/apache/spark/deploy/master/ApplicationInfo.scala

@@ -82,7 +82,7 @@ private[spark] class ApplicationInfo(
     }
   }
 
-  private val myMaxCores = if (desc.maxCores == Int.MaxValue) defaultCores else desc.maxCores
+  private val myMaxCores = desc.maxCores.getOrElse(defaultCores)
 
   def coresLeft: Int = myMaxCores - coresGranted
 

core/src/main/scala/org/apache/spark/deploy/master/Master.scala

@@ -92,6 +92,9 @@ private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Act
 
   // Default maxCores for applications that don't specify it (i.e. pass Int.MaxValue)
   val defaultCores = conf.getInt("spark.deploy.defaultCores", Int.MaxValue)
+  if (defaultCores < 1) {
+    throw new SparkException("spark.deploy.defaultCores must be positive")
+  }
 
   override def preStart() {
     logInfo("Starting Spark master at " + masterUrl)

core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala

@@ -38,7 +38,7 @@ private[spark] class SparkDeploySchedulerBackend(
   var stopping = false
   var shutdownCallback : (SparkDeploySchedulerBackend) => Unit = _
 
-  val maxCores = conf.get("spark.cores.max",  Int.MaxValue.toString).toInt
+  val maxCores = conf.getOption("spark.cores.max").map(_.toInt)
 
   override def start() {
     super.start()

core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala

@@ -70,7 +70,7 @@ class JsonProtocolSuite extends FunSuite {
 
   def createAppDesc() : ApplicationDescription = {
     val cmd = new Command("mainClass", List("arg1", "arg2"), Map())
-    new ApplicationDescription("name", 4, 1234, cmd, "sparkHome", "appUiUrl")
+    new ApplicationDescription("name", Some(4), 1234, cmd, "sparkHome", "appUiUrl")
   }
   def createAppInfo() : ApplicationInfo = {
     new ApplicationInfo(

core/src/test/scala/org/apache/spark/deploy/worker/ExecutorRunnerTest.scala

@@ -27,7 +27,7 @@ class ExecutorRunnerTest extends FunSuite {
   test("command includes appId") {
     def f(s:String) = new File(s)
     val sparkHome = sys.env.get("SPARK_HOME").orElse(sys.props.get("spark.home")).get
-    val appDesc = new ApplicationDescription("app name", 8, 500, Command("foo", Seq(),Map()),
+    val appDesc = new ApplicationDescription("app name", Some(8), 500, Command("foo", Seq(),Map()),
       sparkHome, "appUiUrl")
     val appId = "12345-worker321-9876"
     val er = new ExecutorRunner(appId, 1, appDesc, 8, 500, null, "blah", "worker321", f(sparkHome),

docs/configuration.md

@@ -418,7 +418,7 @@ Apart from these, the following properties are also available, and may be useful
     Whether the standalone cluster manager should spread applications out across nodes or try
     to consolidate them onto as few nodes as possible. Spreading out is usually better for
     data locality in HDFS, but consolidating is more efficient for compute-intensive workloads. <br/>
-    <b>Note:</b> this setting needs to be configured in the cluster master, not in individual
+    <b>Note:</b> this setting needs to be configured in the standalone cluster master, not in individual
     applications; you can set it through <code>SPARK_JAVA_OPTS</code> in <code>spark-env.sh</code>.
   </td>
 </tr>
@@ -431,7 +431,7 @@ Apart from these, the following properties are also available, and may be useful
     cores unless they configure <code>spark.cores.max</code> themselves.
     Set this lower on a shared cluster to prevent users from grabbing
     the whole cluster by default. <br/>
-    <b>Note:</b> this setting needs to be configured in the cluster master, not in individual
+    <b>Note:</b> this setting needs to be configured in the standalone cluster master, not in individual
     applications; you can set it through <code>SPARK_JAVA_OPTS</code> in <code>spark-env.sh</code>.
   </td>
 </tr>