diff --git a/core/src/main/scala/org/apache/spark/Partitioner.scala b/core/src/main/scala/org/apache/spark/Partitioner.scala
index fc0a7498820b5039c54615044792207bf4ca276c..3081f927cc3cb2a66a148915fb10344bae228cfa 100644
--- a/core/src/main/scala/org/apache/spark/Partitioner.scala
+++ b/core/src/main/scala/org/apache/spark/Partitioner.scala
@@ -49,7 +49,7 @@ object Partitioner {
    */
   def defaultPartitioner(rdd: RDD[_], others: RDD[_]*): Partitioner = {
     val bySize = (Seq(rdd) ++ others).sortBy(_.partitions.size).reverse
-    for (r <- bySize if r.partitioner != None) {
+    for (r <- bySize if r.partitioner.isDefined) {
       return r.partitioner.get
     }
     if (rdd.context.conf.contains("spark.default.parallelism")) {
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
index 9485bfd89eb5797c21bdd06ea217c6cb0bb89508..f29a6ad2e7b92c9a876a7cf636929166718374c7 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
@@ -67,7 +67,7 @@ private[spark] class ApplicationPage(parent: MasterWebUI) {
               <li><strong>User:</strong> {app.desc.user}</li>
               <li><strong>Cores:</strong>
                 {
-                if (app.desc.maxCores == None) {
+                if (app.desc.maxCores.isEmpty) {
                   "Unlimited (%s granted)".format(app.coresGranted)
                 } else {
                   "%s (%s granted, %s left)".format(
diff --git a/core/src/main/scala/org/apache/spark/metrics/MetricsConfig.scala b/core/src/main/scala/org/apache/spark/metrics/MetricsConfig.scala
index 6f9f29969eaec85d315c964092c6c815516e75e8..e54ac0b332093b0306473c08d8871213105f7487 100644
--- a/core/src/main/scala/org/apache/spark/metrics/MetricsConfig.scala
+++ b/core/src/main/scala/org/apache/spark/metrics/MetricsConfig.scala
@@ -80,7 +80,7 @@ private[spark] class MetricsConfig(val configFile: Option[String]) extends Loggi
     val subProperties = new mutable.HashMap[String, Properties]
     import scala.collection.JavaConversions._
     prop.foreach { kv =>
-      if (regex.findPrefixOf(kv._1) != None) {
+      if (regex.findPrefixOf(kv._1).isDefined) {
         val regex(prefix, suffix) = kv._1
         subProperties.getOrElseUpdate(prefix, new Properties).setProperty(suffix, kv._2)
       }
diff --git a/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala b/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala
index d71069444a73f498eac40995755362f9afb4f9d9..423ff67a5fd43700e586b9e28930ef0f532090d8 100644
--- a/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala
+++ b/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala
@@ -71,7 +71,7 @@ private[spark] class ApproximateActionListener[T, U, R](
     val finishTime = startTime + timeout
     while (true) {
       val time = System.currentTimeMillis()
-      if (failure != None) {
+      if (failure.isDefined) {
         throw failure.get
       } else if (finishedTasks == totalTasks) {
         return new PartialResult(evaluator.currentResult(), true)
diff --git a/core/src/main/scala/org/apache/spark/partial/PartialResult.scala b/core/src/main/scala/org/apache/spark/partial/PartialResult.scala
index 5ce49b8100ee6ad42afa29b4add097c0bb3f3742..812368e04ac0d1115ee24e2f09ef4f790c3ff777 100644
--- a/core/src/main/scala/org/apache/spark/partial/PartialResult.scala
+++ b/core/src/main/scala/org/apache/spark/partial/PartialResult.scala
@@ -31,10 +31,10 @@ class PartialResult[R](initialVal: R, isFinal: Boolean) {
    * Blocking method to wait for and return the final value.
    */
   def getFinalValue(): R = synchronized {
-    while (finalValue == None && failure == None) {
+    while (finalValue.isEmpty && failure.isEmpty) {
       this.wait()
     }
-    if (finalValue != None) {
+    if (finalValue.isDefined) {
       return finalValue.get
     } else {
       throw failure.get
@@ -46,11 +46,11 @@ class PartialResult[R](initialVal: R, isFinal: Boolean) {
    * is supported per PartialResult.
    */
   def onComplete(handler: R => Unit): PartialResult[R] = synchronized {
-    if (completionHandler != None) {
+    if (completionHandler.isDefined) {
       throw new UnsupportedOperationException("onComplete cannot be called twice")
     }
     completionHandler = Some(handler)
-    if (finalValue != None) {
+    if (finalValue.isDefined) {
       // We already have a final value, so let's call the handler
       handler(finalValue.get)
     }
@@ -63,11 +63,11 @@ class PartialResult[R](initialVal: R, isFinal: Boolean) {
    */
   def onFail(handler: Exception => Unit) {
     synchronized {
-      if (failureHandler != None) {
+      if (failureHandler.isDefined) {
         throw new UnsupportedOperationException("onFail cannot be called twice")
       }
       failureHandler = Some(handler)
-      if (failure != None) {
+      if (failure.isDefined) {
         // We already have a failure, so let's call the handler
         handler(failure.get)
       }
@@ -102,7 +102,7 @@ class PartialResult[R](initialVal: R, isFinal: Boolean) {
 
   private[spark] def setFinalValue(value: R) {
     synchronized {
-      if (finalValue != None) {
+      if (finalValue.isDefined) {
         throw new UnsupportedOperationException("setFinalValue called twice on a PartialResult")
       }
       finalValue = Some(value)
@@ -117,7 +117,7 @@ class PartialResult[R](initialVal: R, isFinal: Boolean) {
 
   private[spark] def setFailure(exception: Exception) {
     synchronized {
-      if (failure != None) {
+      if (failure.isDefined) {
         throw new UnsupportedOperationException("setFailure called twice on a PartialResult")
       }
       failure = Some(exception)
diff --git a/core/src/main/scala/org/apache/spark/rdd/RDD.scala b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
index cd90a1561a975e4424690491188daf007ddbf2c9..1472c92b6031d8d9123d6fa0667e246572836acf 100644
--- a/core/src/main/scala/org/apache/spark/rdd/RDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
@@ -666,7 +666,7 @@ abstract class RDD[T: ClassTag](
     }
     var jobResult: Option[T] = None
     val mergeResult = (index: Int, taskResult: Option[T]) => {
-      if (taskResult != None) {
+      if (taskResult.isDefined) {
         jobResult = jobResult match {
           case Some(value) => Some(f(value, taskResult.get))
           case None => taskResult
diff --git a/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala b/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala
index 7046c06d2057d68e6e16f4d6bc2e15e5cbda42db..237cbf4c0c942c139f6405407ae24affa03e5c99 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala
@@ -877,7 +877,7 @@ class DAGScheduler(
               logInfo("running: " + running)
               logInfo("waiting: " + waiting)
               logInfo("failed: " + failed)
-              if (stage.shuffleDep != None) {
+              if (stage.shuffleDep.isDefined) {
                 // We supply true to increment the epoch number here in case this is a
                 // recomputation of the map outputs. In that case, some nodes may have cached
                 // locations with holes (from when we detected the error) and will need the
diff --git a/core/src/main/scala/org/apache/spark/scheduler/Stage.scala b/core/src/main/scala/org/apache/spark/scheduler/Stage.scala
index c60e9896dee4ffe0ef2254deed52fc157bbe7b3b..520c0b29e3536c4681d2d3710ec1d5a47e07cb58 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/Stage.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/Stage.scala
@@ -46,7 +46,7 @@ private[spark] class Stage(
     callSite: Option[String])
   extends Logging {
 
-  val isShuffleMap = shuffleDep != None
+  val isShuffleMap = shuffleDep.isDefined
   val numPartitions = rdd.partitions.size
   val outputLocs = Array.fill[List[MapStatus]](numPartitions)(Nil)
   var numAvailableOutputs = 0
diff --git a/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala b/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala
index 6cc608ea5bc690ab91a91fb482beddd817a95843..83ba5840155fb6a0a87cfec4b456e461b02fe937 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala
@@ -293,7 +293,7 @@ private[spark] class TaskSchedulerImpl(
       }
     }
     // Update the DAGScheduler without holding a lock on this, since that can deadlock
-    if (failedExecutor != None) {
+    if (failedExecutor.isDefined) {
       dagScheduler.executorLost(failedExecutor.get)
       backend.reviveOffers()
     }
@@ -387,7 +387,7 @@ private[spark] class TaskSchedulerImpl(
       }
     }
     // Call dagScheduler.executorLost without holding the lock on this to prevent deadlock
-    if (failedExecutor != None) {
+    if (failedExecutor.isDefined) {
       dagScheduler.executorLost(failedExecutor.get)
       backend.reviveOffers()
     }
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala b/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala
index 42f52d7b26a04b677a66e3d14a8f4a0cd797b598..3efe738a08f666a883c6cacb3f23a95873aeb441 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala
@@ -111,7 +111,7 @@ private[spark] object BlockManagerWorker extends Logging {
     val blockMessageArray = new BlockMessageArray(blockMessage)
     val resultMessage = connectionManager.sendMessageReliablySync(
         toConnManagerId, blockMessageArray.toBufferMessage)
-    resultMessage != None
+    resultMessage.isDefined
   }
 
   def syncGetBlock(msg: GetBlock, toConnManagerId: ConnectionManagerId): ByteBuffer = {
diff --git a/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala b/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala
index 27f057b9f22f4df42432acefb9efd8e4cab9e3aa..eb5a18521683e2be27d4ae0fbaa2eb499e945a50 100644
--- a/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala
@@ -214,7 +214,7 @@ private class MemoryStore(blockManager: BlockManager, maxMemory: Long)
         while (maxMemory - (currentMemory - selectedMemory) < space && iterator.hasNext) {
           val pair = iterator.next()
           val blockId = pair.getKey
-          if (rddToAdd != None && rddToAdd == getRddId(blockId)) {
+          if (rddToAdd.isDefined && rddToAdd == getRddId(blockId)) {
             logInfo("Will not store " + blockIdToAdd + " as it would require dropping another " +
               "block from the same RDD")
             return false
diff --git a/core/src/main/scala/org/apache/spark/util/Utils.scala b/core/src/main/scala/org/apache/spark/util/Utils.scala
index 64acfbd3526f3a36a0af4f22e5f635a3a87185ab..8447773343d25a8b8731f81a5d53ff4363d7a319 100644
--- a/core/src/main/scala/org/apache/spark/util/Utils.scala
+++ b/core/src/main/scala/org/apache/spark/util/Utils.scala
@@ -652,7 +652,7 @@ private[spark] object Utils extends Logging {
 
     for (el <- trace) {
       if (!finished) {
-        if (SPARK_CLASS_REGEX.findFirstIn(el.getClassName) != None) {
+        if (SPARK_CLASS_REGEX.findFirstIn(el.getClassName).isDefined) {
           lastSparkMethod = if (el.getMethodName == "<init>") {
             // Spark method is a constructor; get its class name
             el.getClassName.substring(el.getClassName.lastIndexOf('.') + 1)
diff --git a/core/src/test/scala/org/apache/spark/scheduler/TaskSetManagerSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/TaskSetManagerSuite.scala
index c9f6cc5d079b5909459ec4fb843c57c9d0354aef..ecac2f79a25e26b7f62cabebeca4cd28695e7f3b 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/TaskSetManagerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/TaskSetManagerSuite.scala
@@ -287,7 +287,7 @@ class TaskSetManagerSuite extends FunSuite with LocalSparkContext with Logging {
     // after the last failure.
     (1 to manager.maxTaskFailures).foreach { index =>
       val offerResult = manager.resourceOffer("exec1", "host1", 1, ANY)
-      assert(offerResult != None,
+      assert(offerResult.isDefined,
         "Expect resource offer on iteration %s to return a task".format(index))
       assert(offerResult.get.index === 0)
       manager.handleFailedTask(offerResult.get.taskId, TaskState.FINISHED, Some(TaskResultLost))
diff --git a/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala b/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala
index 18aa587662d245b9444ddbb9d68c2c6bc1c1046f..85011c6451777ef6b5e72a0128e0bd7fc38beafe 100644
--- a/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala
@@ -137,9 +137,9 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a3", a3, StorageLevel.MEMORY_ONLY, tellMaster = false)
 
     // Checking whether blocks are in memory
-    assert(store.getSingle("a1") != None, "a1 was not in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
 
     // Checking whether master knows about the blocks or not
     assert(master.getLocations("a1").size > 0, "master was not told about a1")
@@ -186,9 +186,9 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     val memStatus = master.getMemoryStatus.head._2
     assert(memStatus._1 == 2000L, "total memory " + memStatus._1 + " should equal 2000")
     assert(memStatus._2 <= 1200L, "remaining memory " + memStatus._2 + " should <= 1200")
-    assert(store.getSingle("a1-to-remove") != None, "a1 was not in store")
-    assert(store.getSingle("a2-to-remove") != None, "a2 was not in store")
-    assert(store.getSingle("a3-to-remove") != None, "a3 was not in store")
+    assert(store.getSingle("a1-to-remove").isDefined, "a1 was not in store")
+    assert(store.getSingle("a2-to-remove").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3-to-remove").isDefined, "a3 was not in store")
 
     // Checking whether master knows about the blocks or not
     assert(master.getLocations("a1-to-remove").size > 0, "master was not told about a1")
@@ -259,7 +259,7 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
 
     store.putSingle("a1", a1, StorageLevel.MEMORY_ONLY)
 
-    assert(store.getSingle("a1") != None, "a1 was not in store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
     assert(master.getLocations("a1").size > 0, "master was not told about a1")
 
     master.removeExecutor(store.blockManagerId.executorId)
@@ -333,14 +333,14 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_ONLY)
     store.putSingle("a2", a2, StorageLevel.MEMORY_ONLY)
     store.putSingle("a3", a3, StorageLevel.MEMORY_ONLY)
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
     assert(store.getSingle("a1") === None, "a1 was in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
     // At this point a2 was gotten last, so LRU will getSingle rid of a3
     store.putSingle("a1", a1, StorageLevel.MEMORY_ONLY)
-    assert(store.getSingle("a1") != None, "a1 was not in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
     assert(store.getSingle("a3") === None, "a3 was in store")
   }
 
@@ -352,14 +352,14 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_ONLY_SER)
     store.putSingle("a2", a2, StorageLevel.MEMORY_ONLY_SER)
     store.putSingle("a3", a3, StorageLevel.MEMORY_ONLY_SER)
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
     assert(store.getSingle("a1") === None, "a1 was in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
     // At this point a2 was gotten last, so LRU will getSingle rid of a3
     store.putSingle("a1", a1, StorageLevel.MEMORY_ONLY_SER)
-    assert(store.getSingle("a1") != None, "a1 was not in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
     assert(store.getSingle("a3") === None, "a3 was in store")
   }
 
@@ -374,8 +374,8 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     // Even though we accessed rdd_0_3 last, it should not have replaced partitions 1 and 2
     // from the same RDD
     assert(store.getSingle(rdd(0, 3)) === None, "rdd_0_3 was in store")
-    assert(store.getSingle(rdd(0, 2)) != None, "rdd_0_2 was not in store")
-    assert(store.getSingle(rdd(0, 1)) != None, "rdd_0_1 was not in store")
+    assert(store.getSingle(rdd(0, 2)).isDefined, "rdd_0_2 was not in store")
+    assert(store.getSingle(rdd(0, 1)).isDefined, "rdd_0_1 was not in store")
     // Check that rdd_0_3 doesn't replace them even after further accesses
     assert(store.getSingle(rdd(0, 3)) === None, "rdd_0_3 was in store")
     assert(store.getSingle(rdd(0, 3)) === None, "rdd_0_3 was in store")
@@ -392,7 +392,7 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     assert(!store.memoryStore.contains(rdd(0, 1)), "rdd_0_1 was in store")
     assert(store.memoryStore.contains(rdd(0, 2)), "rdd_0_2 was not in store")
     // Do a get() on rdd_0_2 so that it is the most recently used item
-    assert(store.getSingle(rdd(0, 2)) != None, "rdd_0_2 was not in store")
+    assert(store.getSingle(rdd(0, 2)).isDefined, "rdd_0_2 was not in store")
     // Put in more partitions from RDD 0; they should replace rdd_1_1
     store.putSingle(rdd(0, 3), new Array[Byte](400), StorageLevel.MEMORY_ONLY)
     store.putSingle(rdd(0, 4), new Array[Byte](400), StorageLevel.MEMORY_ONLY)
@@ -413,9 +413,9 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.DISK_ONLY)
     store.putSingle("a2", a2, StorageLevel.DISK_ONLY)
     store.putSingle("a3", a3, StorageLevel.DISK_ONLY)
-    assert(store.getSingle("a2") != None, "a2 was in store")
-    assert(store.getSingle("a3") != None, "a3 was in store")
-    assert(store.getSingle("a1") != None, "a1 was in store")
+    assert(store.getSingle("a2").isDefined, "a2 was in store")
+    assert(store.getSingle("a3").isDefined, "a3 was in store")
+    assert(store.getSingle("a1").isDefined, "a1 was in store")
   }
 
   test("disk and memory storage") {
@@ -426,11 +426,11 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_AND_DISK)
     store.putSingle("a2", a2, StorageLevel.MEMORY_AND_DISK)
     store.putSingle("a3", a3, StorageLevel.MEMORY_AND_DISK)
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
     assert(store.memoryStore.getValues("a1") == None, "a1 was in memory store")
-    assert(store.getSingle("a1") != None, "a1 was not in store")
-    assert(store.memoryStore.getValues("a1") != None, "a1 was not in memory store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
+    assert(store.memoryStore.getValues("a1").isDefined, "a1 was not in memory store")
   }
 
   test("disk and memory storage with getLocalBytes") {
@@ -441,11 +441,11 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_AND_DISK)
     store.putSingle("a2", a2, StorageLevel.MEMORY_AND_DISK)
     store.putSingle("a3", a3, StorageLevel.MEMORY_AND_DISK)
-    assert(store.getLocalBytes("a2") != None, "a2 was not in store")
-    assert(store.getLocalBytes("a3") != None, "a3 was not in store")
+    assert(store.getLocalBytes("a2").isDefined, "a2 was not in store")
+    assert(store.getLocalBytes("a3").isDefined, "a3 was not in store")
     assert(store.memoryStore.getValues("a1") == None, "a1 was in memory store")
-    assert(store.getLocalBytes("a1") != None, "a1 was not in store")
-    assert(store.memoryStore.getValues("a1") != None, "a1 was not in memory store")
+    assert(store.getLocalBytes("a1").isDefined, "a1 was not in store")
+    assert(store.memoryStore.getValues("a1").isDefined, "a1 was not in memory store")
   }
 
   test("disk and memory storage with serialization") {
@@ -456,11 +456,11 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_AND_DISK_SER)
     store.putSingle("a2", a2, StorageLevel.MEMORY_AND_DISK_SER)
     store.putSingle("a3", a3, StorageLevel.MEMORY_AND_DISK_SER)
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
     assert(store.memoryStore.getValues("a1") == None, "a1 was in memory store")
-    assert(store.getSingle("a1") != None, "a1 was not in store")
-    assert(store.memoryStore.getValues("a1") != None, "a1 was not in memory store")
+    assert(store.getSingle("a1").isDefined, "a1 was not in store")
+    assert(store.memoryStore.getValues("a1").isDefined, "a1 was not in memory store")
   }
 
   test("disk and memory storage with serialization and getLocalBytes") {
@@ -471,11 +471,11 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a1", a1, StorageLevel.MEMORY_AND_DISK_SER)
     store.putSingle("a2", a2, StorageLevel.MEMORY_AND_DISK_SER)
     store.putSingle("a3", a3, StorageLevel.MEMORY_AND_DISK_SER)
-    assert(store.getLocalBytes("a2") != None, "a2 was not in store")
-    assert(store.getLocalBytes("a3") != None, "a3 was not in store")
+    assert(store.getLocalBytes("a2").isDefined, "a2 was not in store")
+    assert(store.getLocalBytes("a3").isDefined, "a3 was not in store")
     assert(store.memoryStore.getValues("a1") == None, "a1 was in memory store")
-    assert(store.getLocalBytes("a1") != None, "a1 was not in store")
-    assert(store.memoryStore.getValues("a1") != None, "a1 was not in memory store")
+    assert(store.getLocalBytes("a1").isDefined, "a1 was not in store")
+    assert(store.memoryStore.getValues("a1").isDefined, "a1 was not in memory store")
   }
 
   test("LRU with mixed storage levels") {
@@ -489,18 +489,18 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.putSingle("a2", a2, StorageLevel.MEMORY_ONLY_SER)
     store.putSingle("a3", a3, StorageLevel.DISK_ONLY)
     // At this point LRU should not kick in because a3 is only on disk
-    assert(store.getSingle("a1") != None, "a2 was not in store")
-    assert(store.getSingle("a2") != None, "a3 was not in store")
-    assert(store.getSingle("a3") != None, "a1 was not in store")
-    assert(store.getSingle("a1") != None, "a2 was not in store")
-    assert(store.getSingle("a2") != None, "a3 was not in store")
-    assert(store.getSingle("a3") != None, "a1 was not in store")
+    assert(store.getSingle("a1").isDefined, "a2 was not in store")
+    assert(store.getSingle("a2").isDefined, "a3 was not in store")
+    assert(store.getSingle("a3").isDefined, "a1 was not in store")
+    assert(store.getSingle("a1").isDefined, "a2 was not in store")
+    assert(store.getSingle("a2").isDefined, "a3 was not in store")
+    assert(store.getSingle("a3").isDefined, "a1 was not in store")
     // Now let's add in a4, which uses both disk and memory; a1 should drop out
     store.putSingle("a4", a4, StorageLevel.MEMORY_AND_DISK_SER)
     assert(store.getSingle("a1") == None, "a1 was in store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
-    assert(store.getSingle("a3") != None, "a3 was not in store")
-    assert(store.getSingle("a4") != None, "a4 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
+    assert(store.getSingle("a3").isDefined, "a3 was not in store")
+    assert(store.getSingle("a4").isDefined, "a4 was not in store")
   }
 
   test("in-memory LRU with streams") {
@@ -511,18 +511,18 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.put("list1", list1.iterator, StorageLevel.MEMORY_ONLY, tellMaster = true)
     store.put("list2", list2.iterator, StorageLevel.MEMORY_ONLY, tellMaster = true)
     store.put("list3", list3.iterator, StorageLevel.MEMORY_ONLY, tellMaster = true)
-    assert(store.get("list2") != None, "list2 was not in store")
+    assert(store.get("list2").isDefined, "list2 was not in store")
     assert(store.get("list2").get.size == 2)
-    assert(store.get("list3") != None, "list3 was not in store")
+    assert(store.get("list3").isDefined, "list3 was not in store")
     assert(store.get("list3").get.size == 2)
     assert(store.get("list1") === None, "list1 was in store")
-    assert(store.get("list2") != None, "list2 was not in store")
+    assert(store.get("list2").isDefined, "list2 was not in store")
     assert(store.get("list2").get.size == 2)
     // At this point list2 was gotten last, so LRU will getSingle rid of list3
     store.put("list1", list1.iterator, StorageLevel.MEMORY_ONLY, tellMaster = true)
-    assert(store.get("list1") != None, "list1 was not in store")
+    assert(store.get("list1").isDefined, "list1 was not in store")
     assert(store.get("list1").get.size == 2)
-    assert(store.get("list2") != None, "list2 was not in store")
+    assert(store.get("list2").isDefined, "list2 was not in store")
     assert(store.get("list2").get.size == 2)
     assert(store.get("list3") === None, "list1 was in store")
   }
@@ -538,26 +538,26 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     store.put("list2", list2.iterator, StorageLevel.MEMORY_ONLY_SER, tellMaster = true)
     store.put("list3", list3.iterator, StorageLevel.DISK_ONLY, tellMaster = true)
     // At this point LRU should not kick in because list3 is only on disk
-    assert(store.get("list1") != None, "list2 was not in store")
+    assert(store.get("list1").isDefined, "list2 was not in store")
     assert(store.get("list1").get.size === 2)
-    assert(store.get("list2") != None, "list3 was not in store")
+    assert(store.get("list2").isDefined, "list3 was not in store")
     assert(store.get("list2").get.size === 2)
-    assert(store.get("list3") != None, "list1 was not in store")
+    assert(store.get("list3").isDefined, "list1 was not in store")
     assert(store.get("list3").get.size === 2)
-    assert(store.get("list1") != None, "list2 was not in store")
+    assert(store.get("list1").isDefined, "list2 was not in store")
     assert(store.get("list1").get.size === 2)
-    assert(store.get("list2") != None, "list3 was not in store")
+    assert(store.get("list2").isDefined, "list3 was not in store")
     assert(store.get("list2").get.size === 2)
-    assert(store.get("list3") != None, "list1 was not in store")
+    assert(store.get("list3").isDefined, "list1 was not in store")
     assert(store.get("list3").get.size === 2)
     // Now let's add in list4, which uses both disk and memory; list1 should drop out
     store.put("list4", list4.iterator, StorageLevel.MEMORY_AND_DISK_SER, tellMaster = true)
     assert(store.get("list1") === None, "list1 was in store")
-    assert(store.get("list2") != None, "list3 was not in store")
+    assert(store.get("list2").isDefined, "list3 was not in store")
     assert(store.get("list2").get.size === 2)
-    assert(store.get("list3") != None, "list1 was not in store")
+    assert(store.get("list3").isDefined, "list1 was not in store")
     assert(store.get("list3").get.size === 2)
-    assert(store.get("list4") != None, "list4 was not in store")
+    assert(store.get("list4").isDefined, "list4 was not in store")
     assert(store.get("list4").get.size === 2)
   }
 
@@ -579,7 +579,7 @@ class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodT
     assert(store.getSingle("a1") === None, "a1 was in store")
     store.putSingle("a2", new Array[Byte](1000), StorageLevel.MEMORY_AND_DISK)
     assert(store.memoryStore.getValues("a2") === None, "a2 was in memory store")
-    assert(store.getSingle("a2") != None, "a2 was not in store")
+    assert(store.getSingle("a2").isDefined, "a2 was not in store")
   }
 
   test("block compression") {