193 files changed, 462 insertions, 418 deletions

diff --git a/bagel/src/main/scala/org/apache/spark/bagel/Bagel.scala b/bagel/src/main/scala/org/apache/spark/bagel/Bagel.scala
index fec8737fcd..44e26bbb9e 100644
--- a/bagel/src/main/scala/org/apache/spark/bagel/Bagel.scala
+++ b/bagel/src/main/scala/org/apache/spark/bagel/Bagel.scala
@@ -19,7 +19,7 @@ package org.apache.spark.bagel
 
 import org.apache.spark._
 import org.apache.spark.SparkContext._
-
+import org.apache.spark.rdd.RDD
 import org.apache.spark.storage.StorageLevel
 
 object Bagel extends Logging {
diff --git a/core/src/main/scala/org/apache/spark/Accumulators.scala b/core/src/main/scala/org/apache/spark/Accumulators.scala
index 5177ee58fa..6e922a612a 100644
--- a/core/src/main/scala/org/apache/spark/Accumulators.scala
+++ b/core/src/main/scala/org/apache/spark/Accumulators.scala
@@ -21,6 +21,7 @@ import java.io._
 
 import scala.collection.mutable.Map
 import scala.collection.generic.Growable
+import org.apache.spark.serializer.JavaSerializer
 
 /**
  * A datatype that can be accumulated, i.e. has an commutative and associative "add" operation,
diff --git a/core/src/main/scala/org/apache/spark/CacheManager.scala b/core/src/main/scala/org/apache/spark/CacheManager.scala
index 42e465b9d8..e299a106ee 100644
--- a/core/src/main/scala/org/apache/spark/CacheManager.scala
+++ b/core/src/main/scala/org/apache/spark/CacheManager.scala
@@ -19,6 +19,7 @@ package org.apache.spark
 
 import scala.collection.mutable.{ArrayBuffer, HashSet}
 import org.apache.spark.storage.{BlockManager, StorageLevel}
+import org.apache.spark.rdd.RDD
 
 
 /** Spark class responsible for passing RDDs split contents to the BlockManager and making
diff --git a/core/src/main/scala/org/apache/spark/Dependency.scala b/core/src/main/scala/org/apache/spark/Dependency.scala
index cc3c2474a6..cc30105940 100644
--- a/core/src/main/scala/org/apache/spark/Dependency.scala
+++ b/core/src/main/scala/org/apache/spark/Dependency.scala
@@ -17,6 +17,8 @@
 
 package org.apache.spark
 
+import org.apache.spark.rdd.RDD
+
 /**
  * Base class for dependencies.
  */
diff --git a/core/src/main/scala/org/apache/spark/HttpFileServer.scala b/core/src/main/scala/org/apache/spark/HttpFileServer.scala
index 9b3a896648..ad1ee20045 100644
--- a/core/src/main/scala/org/apache/spark/HttpFileServer.scala
+++ b/core/src/main/scala/org/apache/spark/HttpFileServer.scala
@@ -19,6 +19,7 @@ package org.apache.spark
 
 import java.io.{File}
 import com.google.common.io.Files
+import org.apache.spark.util.Utils
 
 private[spark] class HttpFileServer extends Logging {
   
diff --git a/core/src/main/scala/org/apache/spark/HttpServer.scala b/core/src/main/scala/org/apache/spark/HttpServer.scala
index db36c7c9dd..cdfc9dd54e 100644
--- a/core/src/main/scala/org/apache/spark/HttpServer.scala
+++ b/core/src/main/scala/org/apache/spark/HttpServer.scala
@@ -26,6 +26,7 @@ import org.eclipse.jetty.server.handler.DefaultHandler
 import org.eclipse.jetty.server.handler.HandlerList
 import org.eclipse.jetty.server.handler.ResourceHandler
 import org.eclipse.jetty.util.thread.QueuedThreadPool
+import org.apache.spark.util.Utils
 
 /**
  * Exception type thrown by HttpServer when it is in the wrong state for an operation.
diff --git a/core/src/main/scala/org/apache/spark/MapOutputTracker.scala b/core/src/main/scala/org/apache/spark/MapOutputTracker.scala
index 0f422d910a..ae7cf2a893 100644
--- a/core/src/main/scala/org/apache/spark/MapOutputTracker.scala
+++ b/core/src/main/scala/org/apache/spark/MapOutputTracker.scala
@@ -32,7 +32,7 @@ import akka.util.Duration
 
 import org.apache.spark.scheduler.MapStatus
 import org.apache.spark.storage.BlockManagerId
-import org.apache.spark.util.{MetadataCleaner, TimeStampedHashMap}
+import org.apache.spark.util.{Utils, MetadataCleaner, TimeStampedHashMap}
 
 
 private[spark] sealed trait MapOutputTrackerMessage
diff --git a/core/src/main/scala/org/apache/spark/Partitioner.scala b/core/src/main/scala/org/apache/spark/Partitioner.scala
index 4dce2607b0..0e2c987a59 100644
--- a/core/src/main/scala/org/apache/spark/Partitioner.scala
+++ b/core/src/main/scala/org/apache/spark/Partitioner.scala
@@ -17,6 +17,9 @@
 
 package org.apache.spark
 
+import org.apache.spark.util.Utils
+import org.apache.spark.rdd.RDD
+
 /**
  * An object that defines how the elements in a key-value pair RDD are partitioned by key.
  * Maps each key to a partition ID, from 0 to `numPartitions - 1`.
diff --git a/core/src/main/scala/org/apache/spark/SparkContext.scala b/core/src/main/scala/org/apache/spark/SparkContext.scala
index 1207b242bc..faf0c2362a 100644
--- a/core/src/main/scala/org/apache/spark/SparkContext.scala
+++ b/core/src/main/scala/org/apache/spark/SparkContext.scala
@@ -54,17 +54,15 @@ import org.apache.mesos.MesosNativeLibrary
 
 import org.apache.spark.deploy.LocalSparkCluster
 import org.apache.spark.partial.{ApproximateEvaluator, PartialResult}
-import org.apache.spark.rdd.{CheckpointRDD, HadoopRDD, NewHadoopRDD, UnionRDD, ParallelCollectionRDD,
-  OrderedRDDFunctions}
+import org.apache.spark.rdd._
 import org.apache.spark.scheduler._
 import org.apache.spark.scheduler.cluster.{StandaloneSchedulerBackend, SparkDeploySchedulerBackend,
   ClusterScheduler, Schedulable, SchedulingMode}
 import org.apache.spark.scheduler.local.LocalScheduler
 import org.apache.spark.scheduler.mesos.{CoarseMesosSchedulerBackend, MesosSchedulerBackend}
-import org.apache.spark.storage.{StorageStatus, StorageUtils, RDDInfo, BlockManagerSource}
+import org.apache.spark.storage.{StorageUtils, BlockManagerSource}
 import org.apache.spark.ui.SparkUI
-import org.apache.spark.util.{MetadataCleaner, TimeStampedHashMap}
-import scala.Some
+import org.apache.spark.util.{ClosureCleaner, Utils, MetadataCleaner, TimeStampedHashMap}
 import org.apache.spark.scheduler.StageInfo
 import org.apache.spark.storage.RDDInfo
 import org.apache.spark.storage.StorageStatus
diff --git a/core/src/main/scala/org/apache/spark/SparkEnv.scala b/core/src/main/scala/org/apache/spark/SparkEnv.scala
index 6e6fe5df6b..478e5a0aaf 100644
--- a/core/src/main/scala/org/apache/spark/SparkEnv.scala
+++ b/core/src/main/scala/org/apache/spark/SparkEnv.scala
@@ -29,7 +29,7 @@ import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.storage.{BlockManagerMasterActor, BlockManager, BlockManagerMaster}
 import org.apache.spark.network.ConnectionManager
 import org.apache.spark.serializer.{Serializer, SerializerManager}
-import org.apache.spark.util.AkkaUtils
+import org.apache.spark.util.{Utils, AkkaUtils}
 import org.apache.spark.api.python.PythonWorkerFactory
 
 
@@ -155,10 +155,10 @@ object SparkEnv extends Logging {
     val serializerManager = new SerializerManager
 
     val serializer = serializerManager.setDefault(
-      System.getProperty("spark.serializer", "org.apache.spark.JavaSerializer"))
+      System.getProperty("spark.serializer", "org.apache.spark.serializer.JavaSerializer"))
 
     val closureSerializer = serializerManager.get(
-      System.getProperty("spark.closure.serializer", "org.apache.spark.JavaSerializer"))
+      System.getProperty("spark.closure.serializer", "org.apache.spark.serializer.JavaSerializer"))
 
     def registerOrLookup(name: String, newActor: => Actor): ActorRef = {
       if (isDriver) {
diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala b/core/src/main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala
index cb25ff728e..5fd1fab580 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.api.java
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext.doubleRDDToDoubleRDDFunctions
 import org.apache.spark.api.java.function.{Function => JFunction}
 import org.apache.spark.util.StatCounter
diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala b/core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala
index 09da35aee6..a6518abf45 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala
@@ -33,12 +33,12 @@ import org.apache.hadoop.conf.Configuration
 import org.apache.spark.HashPartitioner
 import org.apache.spark.Partitioner
 import org.apache.spark.Partitioner._
-import org.apache.spark.RDD
 import org.apache.spark.SparkContext.rddToPairRDDFunctions
 import org.apache.spark.api.java.function.{Function2 => JFunction2}
 import org.apache.spark.api.java.function.{Function => JFunction}
 import org.apache.spark.partial.BoundedDouble
 import org.apache.spark.partial.PartialResult
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.OrderedRDDFunctions
 import org.apache.spark.storage.StorageLevel
 
diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala b/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala
index 68cfcf5999..eec58abdd6 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala
@@ -18,6 +18,7 @@
 package org.apache.spark.api.java
 
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.api.java.function.{Function => JFunction}
 import org.apache.spark.storage.StorageLevel
 
diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala b/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala
index 1ad8514980..7e6e691f11 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala
@@ -21,13 +21,15 @@ import java.util.{List => JList, Comparator}
 import scala.Tuple2
 import scala.collection.JavaConversions._
 
+import com.google.common.base.Optional
 import org.apache.hadoop.io.compress.CompressionCodec
-import org.apache.spark.{SparkContext, Partition, RDD, TaskContext}
+
+import org.apache.spark.{SparkContext, Partition, TaskContext}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.api.java.JavaPairRDD._
 import org.apache.spark.api.java.function.{Function2 => JFunction2, Function => JFunction, _}
 import org.apache.spark.partial.{PartialResult, BoundedDouble}
 import org.apache.spark.storage.StorageLevel
-import com.google.common.base.Optional
 
 
 trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable {
diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaSparkContext.scala b/core/src/main/scala/org/apache/spark/api/java/JavaSparkContext.scala
index 618a7b3bf7..8869e072bf 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaSparkContext.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaSparkContext.scala
@@ -26,13 +26,13 @@ import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.mapred.InputFormat
 import org.apache.hadoop.mapred.JobConf
 import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
+import com.google.common.base.Optional
 
-import org.apache.spark.{Accumulable, AccumulableParam, Accumulator, AccumulatorParam, RDD, SparkContext}
+import org.apache.spark.{Accumulable, AccumulableParam, Accumulator, AccumulatorParam, SparkContext}
 import org.apache.spark.SparkContext.IntAccumulatorParam
 import org.apache.spark.SparkContext.DoubleAccumulatorParam
 import org.apache.spark.broadcast.Broadcast
-
-import com.google.common.base.Optional
+import org.apache.spark.rdd.RDD
 
 /**
  * A Java-friendly version of [[org.apache.spark.SparkContext]] that returns [[org.apache.spark.api.java.JavaRDD]]s and
diff --git a/core/src/main/scala/org/apache/spark/api/python/PythonPartitioner.scala b/core/src/main/scala/org/apache/spark/api/python/PythonPartitioner.scala
index eea63d5a4e..b090c6edf3 100644
--- a/core/src/main/scala/org/apache/spark/api/python/PythonPartitioner.scala
+++ b/core/src/main/scala/org/apache/spark/api/python/PythonPartitioner.scala
@@ -18,8 +18,8 @@
 package org.apache.spark.api.python
 
 import org.apache.spark.Partitioner
-import org.apache.spark.Utils
 import java.util.Arrays
+import org.apache.spark.util.Utils
 
 /**
  * A [[org.apache.spark.Partitioner]] that performs handling of byte arrays, for use by the Python API.
diff --git a/core/src/main/scala/org/apache/spark/api/python/PythonRDD.scala b/core/src/main/scala/org/apache/spark/api/python/PythonRDD.scala
index 621f0fe8ee..ccd3833964 100644
--- a/core/src/main/scala/org/apache/spark/api/python/PythonRDD.scala
+++ b/core/src/main/scala/org/apache/spark/api/python/PythonRDD.scala
@@ -26,7 +26,9 @@ import scala.collection.JavaConversions._
 import org.apache.spark.api.java.{JavaSparkContext, JavaPairRDD, JavaRDD}
 import org.apache.spark.broadcast.Broadcast
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.PipedRDD
+import org.apache.spark.util.Utils
 
 
 private[spark] class PythonRDD[T: ClassManifest](
diff --git a/core/src/main/scala/org/apache/spark/broadcast/BitTorrentBroadcast.scala b/core/src/main/scala/org/apache/spark/broadcast/BitTorrentBroadcast.scala
index 99e86237fc..93e7815ab5 100644
--- a/core/src/main/scala/org/apache/spark/broadcast/BitTorrentBroadcast.scala
+++ b/core/src/main/scala/org/apache/spark/broadcast/BitTorrentBroadcast.scala
@@ -27,6 +27,7 @@ import scala.math
 
 import org.apache.spark._
 import org.apache.spark.storage.StorageLevel
+import org.apache.spark.util.Utils
 
 private[spark] class BitTorrentBroadcast[T](@transient var value_ : T, isLocal: Boolean, id: Long)
   extends Broadcast[T](id)
diff --git a/core/src/main/scala/org/apache/spark/broadcast/HttpBroadcast.scala b/core/src/main/scala/org/apache/spark/broadcast/HttpBroadcast.scala
index 7a52ff0769..9db26ae6de 100644
--- a/core/src/main/scala/org/apache/spark/broadcast/HttpBroadcast.scala
+++ b/core/src/main/scala/org/apache/spark/broadcast/HttpBroadcast.scala
@@ -23,10 +23,10 @@ import java.net.URL
 import it.unimi.dsi.fastutil.io.FastBufferedInputStream
 import it.unimi.dsi.fastutil.io.FastBufferedOutputStream
 
-import org.apache.spark.{HttpServer, Logging, SparkEnv, Utils}
+import org.apache.spark.{HttpServer, Logging, SparkEnv}
 import org.apache.spark.io.CompressionCodec
 import org.apache.spark.storage.StorageLevel
-import org.apache.spark.util.{MetadataCleaner, TimeStampedHashSet}
+import org.apache.spark.util.{Utils, MetadataCleaner, TimeStampedHashSet}
 
 
 private[spark] class HttpBroadcast[T](@transient var value_ : T, isLocal: Boolean, id: Long)
diff --git a/core/src/main/scala/org/apache/spark/broadcast/MultiTracker.scala b/core/src/main/scala/org/apache/spark/broadcast/MultiTracker.scala
index 10b910df87..21ec94659e 100644
--- a/core/src/main/scala/org/apache/spark/broadcast/MultiTracker.scala
+++ b/core/src/main/scala/org/apache/spark/broadcast/MultiTracker.scala
@@ -24,6 +24,7 @@ import java.util.Random
 import scala.collection.mutable.Map
 
 import org.apache.spark._
+import org.apache.spark.util.Utils
 
 private object MultiTracker
 extends Logging {
diff --git a/core/src/main/scala/org/apache/spark/broadcast/TreeBroadcast.scala b/core/src/main/scala/org/apache/spark/broadcast/TreeBroadcast.scala
index b5a4ccc0ee..80c97ca073 100644
--- a/core/src/main/scala/org/apache/spark/broadcast/TreeBroadcast.scala
+++ b/core/src/main/scala/org/apache/spark/broadcast/TreeBroadcast.scala
@@ -26,6 +26,7 @@ import scala.math
 
 import org.apache.spark._
 import org.apache.spark.storage.StorageLevel
+import org.apache.spark.util.Utils
 
 private[spark] class TreeBroadcast[T](@transient var value_ : T, isLocal: Boolean, id: Long)
 extends Broadcast[T](id) with Logging with Serializable {
diff --git a/core/src/main/scala/org/apache/spark/deploy/DeployMessage.scala b/core/src/main/scala/org/apache/spark/deploy/DeployMessage.scala
index 4dc6ada2d1..c31619db27 100644
--- a/core/src/main/scala/org/apache/spark/deploy/DeployMessage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/DeployMessage.scala
@@ -19,10 +19,10 @@ package org.apache.spark.deploy
 
 import scala.collection.immutable.List
 
-import org.apache.spark.Utils
 import org.apache.spark.deploy.ExecutorState.ExecutorState
 import org.apache.spark.deploy.master.{WorkerInfo, ApplicationInfo}
 import org.apache.spark.deploy.worker.ExecutorRunner
+import org.apache.spark.util.Utils
 
 
 private[deploy] sealed trait DeployMessage extends Serializable
diff --git a/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala b/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
index af5a4110b0..78e3747ad8 100644
--- a/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
@@ -21,8 +21,8 @@ import akka.actor.{ActorRef, Props, Actor, ActorSystem, Terminated}
 
 import org.apache.spark.deploy.worker.Worker
 import org.apache.spark.deploy.master.Master
-import org.apache.spark.util.AkkaUtils
-import org.apache.spark.{Logging, Utils}
+import org.apache.spark.util.{Utils, AkkaUtils}
+import org.apache.spark.{Logging}
 
 import scala.collection.mutable.ArrayBuffer
 
diff --git a/core/src/main/scala/org/apache/spark/deploy/client/TestClient.scala b/core/src/main/scala/org/apache/spark/deploy/client/TestClient.scala
index 0322029fbd..d5e9a0e095 100644
--- a/core/src/main/scala/org/apache/spark/deploy/client/TestClient.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/client/TestClient.scala
@@ -17,8 +17,8 @@
 
 package org.apache.spark.deploy.client
 
-import org.apache.spark.util.AkkaUtils
-import org.apache.spark.{Logging, Utils}
+import org.apache.spark.util.{Utils, AkkaUtils}
+import org.apache.spark.{Logging}
 import org.apache.spark.deploy.{Command, ApplicationDescription}
 
 private[spark] object TestClient {
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/Master.scala b/core/src/main/scala/org/apache/spark/deploy/master/Master.scala
index 869b2b2646..7cf0a7754f 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/Master.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/Master.scala
@@ -27,12 +27,12 @@ import akka.actor.Terminated
 import akka.remote.{RemoteClientLifeCycleEvent, RemoteClientDisconnected, RemoteClientShutdown}
 import akka.util.duration._
 
-import org.apache.spark.{Logging, SparkException, Utils}
+import org.apache.spark.{Logging, SparkException}
 import org.apache.spark.deploy.{ApplicationDescription, ExecutorState}
 import org.apache.spark.deploy.DeployMessages._
 import org.apache.spark.deploy.master.ui.MasterWebUI
 import org.apache.spark.metrics.MetricsSystem
-import org.apache.spark.util.AkkaUtils
+import org.apache.spark.util.{Utils, AkkaUtils}
 
 
 private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Actor with Logging {
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala b/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
index c86cca278d..9d89b455fb 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
@@ -17,8 +17,7 @@
 
 package org.apache.spark.deploy.master
 
-import org.apache.spark.util.IntParam
-import org.apache.spark.Utils
+import org.apache.spark.util.{Utils, IntParam}
 
 /**
  * Command-line parser for the master.
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/WorkerInfo.scala b/core/src/main/scala/org/apache/spark/deploy/master/WorkerInfo.scala
index 285e07a823..6219f11f2a 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/WorkerInfo.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/WorkerInfo.scala
@@ -19,7 +19,7 @@ package org.apache.spark.deploy.master
 
 import akka.actor.ActorRef
 import scala.collection.mutable
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 private[spark] class WorkerInfo(
   val id: String,
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 6435c7f917..f4e574d15d 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
@@ -31,7 +31,7 @@ import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, RequestMaste
 import org.apache.spark.deploy.JsonProtocol
 import org.apache.spark.deploy.master.ExecutorInfo
 import org.apache.spark.ui.UIUtils
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 private[spark] class ApplicationPage(parent: MasterWebUI) {
   val master = parent.masterActorRef
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
index 58d3863009..d7a57229b0 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
@@ -27,12 +27,12 @@ import akka.util.duration._
 
 import net.liftweb.json.JsonAST.JValue
 
-import org.apache.spark.Utils
 import org.apache.spark.deploy.DeployWebUI
 import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, RequestMasterState}
 import org.apache.spark.deploy.JsonProtocol
 import org.apache.spark.deploy.master.{ApplicationInfo, WorkerInfo}
 import org.apache.spark.ui.UIUtils
+import org.apache.spark.util.Utils
 
 private[spark] class IndexPage(parent: MasterWebUI) {
   val master = parent.masterActorRef
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
index 47b1e521f5..f4df729e87 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
@@ -23,10 +23,11 @@ import javax.servlet.http.HttpServletRequest
 
 import org.eclipse.jetty.server.{Handler, Server}
 
-import org.apache.spark.{Logging, Utils}
+import org.apache.spark.{Logging}
 import org.apache.spark.deploy.master.Master
 import org.apache.spark.ui.JettyUtils
 import org.apache.spark.ui.JettyUtils._
+import org.apache.spark.util.Utils
 
 /**
  * Web UI server for the standalone master.
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/ExecutorRunner.scala b/core/src/main/scala/org/apache/spark/deploy/worker/ExecutorRunner.scala
index 01ce4a6dea..e3dc30eefc 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/ExecutorRunner.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/ExecutorRunner.scala
@@ -25,9 +25,10 @@ import akka.actor.ActorRef
 import com.google.common.base.Charsets
 import com.google.common.io.Files
 
-import org.apache.spark.{Utils, Logging}
+import org.apache.spark.{Logging}
 import org.apache.spark.deploy.{ExecutorState, ApplicationDescription}
 import org.apache.spark.deploy.DeployMessages.ExecutorStateChanged
+import org.apache.spark.util.Utils
 
 /**
  * Manages the execution of one executor process.
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala b/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala
index 86e8e7543b..09530beb3b 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala
@@ -27,13 +27,13 @@ import akka.actor.{ActorRef, Props, Actor, ActorSystem, Terminated}
 import akka.remote.{RemoteClientLifeCycleEvent, RemoteClientShutdown, RemoteClientDisconnected}
 import akka.util.duration._
 
-import org.apache.spark.{Logging, Utils}
+import org.apache.spark.{Logging}
 import org.apache.spark.deploy.ExecutorState
 import org.apache.spark.deploy.DeployMessages._
 import org.apache.spark.deploy.master.Master
 import org.apache.spark.deploy.worker.ui.WorkerWebUI
 import org.apache.spark.metrics.MetricsSystem
-import org.apache.spark.util.AkkaUtils
+import org.apache.spark.util.{Utils, AkkaUtils}
 
 
 private[spark] class Worker(
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala b/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
index 6d91223413..0ae89a864f 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
@@ -17,9 +17,7 @@
 
 package org.apache.spark.deploy.worker
 
-import org.apache.spark.util.IntParam
-import org.apache.spark.util.MemoryParam
-import org.apache.spark.Utils
+import org.apache.spark.util.{Utils, IntParam, MemoryParam}
 import java.lang.management.ManagementFactory
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala b/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
index 6192c2324b..d2d3617498 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
@@ -27,11 +27,11 @@ import akka.util.duration._
 
 import net.liftweb.json.JsonAST.JValue
 
-import org.apache.spark.Utils
 import org.apache.spark.deploy.JsonProtocol
 import org.apache.spark.deploy.DeployMessages.{RequestWorkerState, WorkerStateResponse}
 import org.apache.spark.deploy.worker.ExecutorRunner
 import org.apache.spark.ui.UIUtils
+import org.apache.spark.util.Utils
 
 
 private[spark] class IndexPage(parent: WorkerWebUI) {
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/ui/WorkerWebUI.scala b/core/src/main/scala/org/apache/spark/deploy/worker/ui/WorkerWebUI.scala
index bb8165ac09..95d6007f3b 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/ui/WorkerWebUI.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/ui/WorkerWebUI.scala
@@ -26,10 +26,11 @@ import javax.servlet.http.HttpServletRequest
 import org.eclipse.jetty.server.{Handler, Server}
 
 import org.apache.spark.deploy.worker.Worker
-import org.apache.spark.{Utils, Logging}
+import org.apache.spark.{Logging}
 import org.apache.spark.ui.JettyUtils
 import org.apache.spark.ui.JettyUtils._
 import org.apache.spark.ui.UIUtils
+import org.apache.spark.util.Utils
 
 /**
  * Web UI server for the standalone worker.
diff --git a/core/src/main/scala/org/apache/spark/executor/Executor.scala b/core/src/main/scala/org/apache/spark/executor/Executor.scala
index 5446a3fca9..d365804994 100644
--- a/core/src/main/scala/org/apache/spark/executor/Executor.scala
+++ b/core/src/main/scala/org/apache/spark/executor/Executor.scala
@@ -27,6 +27,7 @@ import scala.collection.mutable.HashMap
 
 import org.apache.spark.scheduler._
 import org.apache.spark._
+import org.apache.spark.util.Utils
 
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
index 410a94df6b..da62091980 100644
--- a/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
+++ b/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
@@ -22,8 +22,9 @@ import org.apache.mesos.{Executor => MesosExecutor, MesosExecutorDriver, MesosNa
 import org.apache.mesos.Protos.{TaskState => MesosTaskState, TaskStatus => MesosTaskStatus, _}
 import org.apache.spark.TaskState.TaskState
 import com.google.protobuf.ByteString
-import org.apache.spark.{Utils, Logging}
+import org.apache.spark.{Logging}
 import org.apache.spark.TaskState
+import org.apache.spark.util.Utils
 
 private[spark] class MesosExecutorBackend
   extends MesosExecutor
diff --git a/core/src/main/scala/org/apache/spark/executor/StandaloneExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/StandaloneExecutorBackend.scala
index 65801f75b7..7839023868 100644
--- a/core/src/main/scala/org/apache/spark/executor/StandaloneExecutorBackend.scala
+++ b/core/src/main/scala/org/apache/spark/executor/StandaloneExecutorBackend.scala
@@ -22,10 +22,10 @@ import java.nio.ByteBuffer
 import akka.actor.{ActorRef, Actor, Props, Terminated}
 import akka.remote.{RemoteClientLifeCycleEvent, RemoteClientShutdown, RemoteClientDisconnected}
 
-import org.apache.spark.{Logging, Utils, SparkEnv}
+import org.apache.spark.{Logging, SparkEnv}
 import org.apache.spark.TaskState.TaskState
 import org.apache.spark.scheduler.cluster.StandaloneClusterMessages._
-import org.apache.spark.util.AkkaUtils
+import org.apache.spark.util.{Utils, AkkaUtils}
 
 
 private[spark] class StandaloneExecutorBackend(
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
index 9e2233c07b..e15a839c4e 100644
--- a/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
+++ b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
@@ -34,6 +34,7 @@ import scala.collection.mutable.ArrayBuffer
 import akka.dispatch.{Await, Promise, ExecutionContext, Future}
 import akka.util.Duration
 import akka.util.duration._
+import org.apache.spark.util.Utils
 
 
 private[spark] class ConnectionManager(port: Int) extends Logging {
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
index 0839c011b8..50dd9bc2d1 100644
--- a/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
+++ b/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
@@ -19,7 +19,7 @@ package org.apache.spark.network
 
 import java.net.InetSocketAddress
 
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 
 private[spark] case class ConnectionManagerId(host: String, port: Int) {
diff --git a/core/src/main/scala/org/apache/spark/package.scala b/core/src/main/scala/org/apache/spark/package.scala
index 1126480689..c0ec527339 100644
--- a/core/src/main/scala/org/apache/spark/package.scala
+++ b/core/src/main/scala/org/apache/spark/package.scala
@@ -1,3 +1,5 @@
+import org.apache.spark.rdd.{SequenceFileRDDFunctions, DoubleRDDFunctions, PairRDDFunctions}
+
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -16,16 +18,17 @@
  */
 
 /**
- * Core Spark functionality. [[org.apache.spark.SparkContext]] serves as the main entry point to Spark, while
- * [[org.apache.spark.RDD]] is the data type representing a distributed collection, and provides most
- * parallel operations. 
+ * Core Spark functionality. [[org.apache.spark.SparkContext]] serves as the main entry point to
+ * Spark, while [[org.apache.spark.rdd.RDD]] is the data type representing a distributed collection,
+ * and provides most parallel operations.
  *
- * In addition, [[org.apache.spark.PairRDDFunctions]] contains operations available only on RDDs of key-value
- * pairs, such as `groupByKey` and `join`; [[org.apache.spark.DoubleRDDFunctions]] contains operations
- * available only on RDDs of Doubles; and [[org.apache.spark.SequenceFileRDDFunctions]] contains operations
- * available on RDDs that can be saved as SequenceFiles. These operations are automatically
- * available on any RDD of the right type (e.g. RDD[(Int, Int)] through implicit conversions when
- * you `import org.apache.spark.SparkContext._`.
+ * In addition, [[org.apache.spark.rdd.PairRDDFunctions]] contains operations available only on RDDs
+ * of key-value pairs, such as `groupByKey` and `join`; [[org.apache.spark.rdd.DoubleRDDFunctions]]
+ * contains operations available only on RDDs of Doubles; and
+ * [[org.apache.spark.rdd.SequenceFileRDDFunctions]] contains operations available on RDDs that can
+ * be saved as SequenceFiles. These operations are automatically available on any RDD of the right
+ * type (e.g. RDD[(Int, Int)] through implicit conversions when you
+ * `import org.apache.spark.SparkContext._`.
  */
 package object spark { 
   // For package docs only
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 c5d51bee50..d71069444a 100644
--- a/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala
+++ b/core/src/main/scala/org/apache/spark/partial/ApproximateActionListener.scala
@@ -19,6 +19,7 @@ package org.apache.spark.partial
 
 import org.apache.spark._
 import org.apache.spark.scheduler.JobListener
+import org.apache.spark.rdd.RDD
 
 /**
  * A JobListener for an approximate single-result action, such as count() or non-parallel reduce().
diff --git a/core/src/main/scala/org/apache/spark/rdd/BlockRDD.scala b/core/src/main/scala/org/apache/spark/rdd/BlockRDD.scala
index 4bb01efa86..bca6956a18 100644
--- a/core/src/main/scala/org/apache/spark/rdd/BlockRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/BlockRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, SparkContext, SparkEnv, Partition, TaskContext}
+import org.apache.spark.{SparkContext, SparkEnv, Partition, TaskContext}
 import org.apache.spark.storage.BlockManager
 
 private[spark] class BlockRDDPartition(val blockId: String, idx: Int) extends Partition {
diff --git a/core/src/main/scala/org/apache/spark/rdd/CoGroupedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/CoGroupedRDD.scala
index dcc35e8d0e..0187256a8e 100644
--- a/core/src/main/scala/org/apache/spark/rdd/CoGroupedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/CoGroupedRDD.scala
@@ -23,7 +23,7 @@ import java.util.{HashMap => JHashMap}
 import scala.collection.JavaConversions
 import scala.collection.mutable.ArrayBuffer
 
-import org.apache.spark.{Partition, Partitioner, RDD, SparkEnv, TaskContext}
+import org.apache.spark.{Partition, Partitioner, SparkEnv, TaskContext}
 import org.apache.spark.{Dependency, OneToOneDependency, ShuffleDependency}
 
 
diff --git a/core/src/main/scala/org/apache/spark/DoubleRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/DoubleRDDFunctions.scala
index dd344491b8..a4bec41752 100644
--- a/core/src/main/scala/org/apache/spark/DoubleRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/DoubleRDDFunctions.scala
@@ -15,17 +15,18 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import org.apache.spark.partial.BoundedDouble
 import org.apache.spark.partial.MeanEvaluator
 import org.apache.spark.partial.PartialResult
 import org.apache.spark.partial.SumEvaluator
 import org.apache.spark.util.StatCounter
+import org.apache.spark.{TaskContext, Logging}
 
 /**
  * Extra functions available on RDDs of Doubles through an implicit conversion.
- * Import `spark.SparkContext._` at the top of your program to use these functions.
+ * Import `org.apache.spark.SparkContext._` at the top of your program to use these functions.
  */
 class DoubleRDDFunctions(self: RDD[Double]) extends Logging with Serializable {
   /** Add up the elements in this RDD. */
diff --git a/core/src/main/scala/org/apache/spark/rdd/EmptyRDD.scala b/core/src/main/scala/org/apache/spark/rdd/EmptyRDD.scala
index 24ce4abbc4..c8900d1a93 100644
--- a/core/src/main/scala/org/apache/spark/rdd/EmptyRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/EmptyRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, SparkContext, SparkEnv, Partition, TaskContext}
+import org.apache.spark.{SparkContext, SparkEnv, Partition, TaskContext}
 
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/rdd/FilteredRDD.scala b/core/src/main/scala/org/apache/spark/rdd/FilteredRDD.scala
index 4df8ceb58b..5312dc0b59 100644
--- a/core/src/main/scala/org/apache/spark/rdd/FilteredRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/FilteredRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{OneToOneDependency, RDD, Partition, TaskContext}
+import org.apache.spark.{OneToOneDependency, Partition, TaskContext}
 
 private[spark] class FilteredRDD[T: ClassManifest](
     prev: RDD[T],
diff --git a/core/src/main/scala/org/apache/spark/rdd/FlatMappedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/FlatMappedRDD.scala
index 2bf7653af1..cbdf6d84c0 100644
--- a/core/src/main/scala/org/apache/spark/rdd/FlatMappedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/FlatMappedRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 
 private[spark]
diff --git a/core/src/main/scala/org/apache/spark/rdd/FlatMappedValuesRDD.scala b/core/src/main/scala/org/apache/spark/rdd/FlatMappedValuesRDD.scala
index e544720b05..82000bac09 100644
--- a/core/src/main/scala/org/apache/spark/rdd/FlatMappedValuesRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/FlatMappedValuesRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{TaskContext, Partition, RDD}
+import org.apache.spark.{TaskContext, Partition}
 
 
 private[spark]
diff --git a/core/src/main/scala/org/apache/spark/rdd/GlommedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/GlommedRDD.scala
index 2ce94199f2..829545d7b0 100644
--- a/core/src/main/scala/org/apache/spark/rdd/GlommedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/GlommedRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 private[spark] class GlommedRDD[T: ClassManifest](prev: RDD[T])
   extends RDD[Array[T]](prev) {
diff --git a/core/src/main/scala/org/apache/spark/rdd/HadoopRDD.scala b/core/src/main/scala/org/apache/spark/rdd/HadoopRDD.scala
index 08e6154bb9..2cb6734e41 100644
--- a/core/src/main/scala/org/apache/spark/rdd/HadoopRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/HadoopRDD.scala
@@ -18,21 +18,15 @@
 package org.apache.spark.rdd
 
 import java.io.EOFException
-import java.util.NoSuchElementException
 
-import org.apache.hadoop.io.LongWritable
-import org.apache.hadoop.io.NullWritable
-import org.apache.hadoop.io.Text
-import org.apache.hadoop.mapred.FileInputFormat
 import org.apache.hadoop.mapred.InputFormat
 import org.apache.hadoop.mapred.InputSplit
 import org.apache.hadoop.mapred.JobConf
-import org.apache.hadoop.mapred.TextInputFormat
 import org.apache.hadoop.mapred.RecordReader
 import org.apache.hadoop.mapred.Reporter
 import org.apache.hadoop.util.ReflectionUtils
 
-import org.apache.spark.{Dependency, Logging, Partition, RDD, SerializableWritable, SparkContext, SparkEnv, TaskContext}
+import org.apache.spark.{Logging, Partition, SerializableWritable, SparkContext, SparkEnv, TaskContext}
 import org.apache.spark.util.NextIterator
 import org.apache.hadoop.conf.{Configuration, Configurable}
 
diff --git a/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala b/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala
index 3db460b3ce..aca0146884 100644
--- a/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala
@@ -19,7 +19,7 @@ package org.apache.spark.rdd
 
 import java.sql.{Connection, ResultSet}
 
-import org.apache.spark.{Logging, Partition, RDD, SparkContext, TaskContext}
+import org.apache.spark.{Logging, Partition, SparkContext, TaskContext}
 import org.apache.spark.util.NextIterator
 
 private[spark] class JdbcPartition(idx: Int, val lower: Long, val upper: Long) extends Partition {
diff --git a/core/src/main/scala/org/apache/spark/rdd/MapPartitionsRDD.scala b/core/src/main/scala/org/apache/spark/rdd/MapPartitionsRDD.scala
index 13009d3e17..203179c4ea 100644
--- a/core/src/main/scala/org/apache/spark/rdd/MapPartitionsRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/MapPartitionsRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 
 private[spark]
diff --git a/core/src/main/scala/org/apache/spark/rdd/MapPartitionsWithIndexRDD.scala b/core/src/main/scala/org/apache/spark/rdd/MapPartitionsWithIndexRDD.scala
index 1683050b86..3ed8339010 100644
--- a/core/src/main/scala/org/apache/spark/rdd/MapPartitionsWithIndexRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/MapPartitionsWithIndexRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/rdd/MappedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/MappedRDD.scala
index 26d4806edb..e8be1c4816 100644
--- a/core/src/main/scala/org/apache/spark/rdd/MappedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/MappedRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 private[spark]
 class MappedRDD[U: ClassManifest, T: ClassManifest](prev: RDD[T], f: T => U)
diff --git a/core/src/main/scala/org/apache/spark/rdd/MappedValuesRDD.scala b/core/src/main/scala/org/apache/spark/rdd/MappedValuesRDD.scala
index a405e9acdd..d33c1af581 100644
--- a/core/src/main/scala/org/apache/spark/rdd/MappedValuesRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/MappedValuesRDD.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.rdd
 
 
-import org.apache.spark.{TaskContext, Partition, RDD}
+import org.apache.spark.{TaskContext, Partition}
 
 private[spark]
 class MappedValuesRDD[K, V, U](prev: RDD[_ <: Product2[K, V]], f: V => U)
diff --git a/core/src/main/scala/org/apache/spark/rdd/NewHadoopRDD.scala b/core/src/main/scala/org/apache/spark/rdd/NewHadoopRDD.scala
index 114b504486..7b3a89f7e0 100644
--- a/core/src/main/scala/org/apache/spark/rdd/NewHadoopRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/NewHadoopRDD.scala
@@ -24,7 +24,7 @@ import org.apache.hadoop.conf.{Configurable, Configuration}
 import org.apache.hadoop.io.Writable
 import org.apache.hadoop.mapreduce._
 
-import org.apache.spark.{Dependency, Logging, Partition, RDD, SerializableWritable, SparkContext, TaskContext}
+import org.apache.spark.{Dependency, Logging, Partition, SerializableWritable, SparkContext, TaskContext}
 
 
 private[spark]
diff --git a/core/src/main/scala/org/apache/spark/rdd/OrderedRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/OrderedRDDFunctions.scala
index 4c3df0eaf4..697be8b997 100644
--- a/core/src/main/scala/org/apache/spark/rdd/OrderedRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/OrderedRDDFunctions.scala
@@ -17,12 +17,13 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{RangePartitioner, Logging, RDD}
+import org.apache.spark.{RangePartitioner, Logging}
 
 /**
  * Extra functions available on RDDs of (key, value) pairs where the key is sortable through
- * an implicit conversion. Import `spark.SparkContext._` at the top of your program to use these
- * functions. They will work with any key type that has a `scala.math.Ordered` implementation.
+ * an implicit conversion. Import `org.apache.spark.SparkContext._` at the top of your program to
+ * use these functions. They will work with any key type that has a `scala.math.Ordered`
+ * implementation.
  */
 class OrderedRDDFunctions[K <% Ordered[K]: ClassManifest,
                           V: ClassManifest,
diff --git a/core/src/main/scala/org/apache/spark/PairRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
index d046e7c1a4..a47c512275 100644
--- a/core/src/main/scala/org/apache/spark/PairRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
@@ -15,40 +15,40 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import java.nio.ByteBuffer
-import java.util.{Date, HashMap => JHashMap}
+import java.util.Date
 import java.text.SimpleDateFormat
+import java.util.{HashMap => JHashMap}
 
 import scala.collection.{mutable, Map}
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.JavaConversions._
 
+import org.apache.hadoop.mapred._
+import org.apache.hadoop.io.compress.CompressionCodec
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.Path
-import org.apache.hadoop.io.compress.CompressionCodec
 import org.apache.hadoop.io.SequenceFile.CompressionType
-import org.apache.hadoop.mapred.FileOutputCommitter
 import org.apache.hadoop.mapred.FileOutputFormat
-import org.apache.hadoop.mapred.SparkHadoopWriter
-import org.apache.hadoop.mapred.JobConf
 import org.apache.hadoop.mapred.OutputFormat
-
+import org.apache.hadoop.mapreduce.{OutputFormat => NewOutputFormat}
 import org.apache.hadoop.mapreduce.lib.output.{FileOutputFormat => NewFileOutputFormat}
-import org.apache.hadoop.mapreduce.{OutputFormat => NewOutputFormat,
-    RecordWriter => NewRecordWriter, Job => NewAPIHadoopJob, SparkHadoopMapReduceUtil}
-import org.apache.hadoop.security.UserGroupInformation
+import org.apache.hadoop.mapreduce.SparkHadoopMapReduceUtil
+import org.apache.hadoop.mapreduce.{Job => NewAPIHadoopJob}
+import org.apache.hadoop.mapreduce.{RecordWriter => NewRecordWriter}
 
-import org.apache.spark.partial.BoundedDouble
-import org.apache.spark.partial.PartialResult
-import org.apache.spark.rdd._
+import org.apache.spark._
 import org.apache.spark.SparkContext._
-import org.apache.spark.Partitioner._
+import org.apache.spark.partial.{BoundedDouble, PartialResult}
+import org.apache.spark.Aggregator
+import org.apache.spark.Partitioner
+import org.apache.spark.Partitioner.defaultPartitioner
 
 /**
  * Extra functions available on RDDs of (key, value) pairs through an implicit conversion.
- * Import `spark.SparkContext._` at the top of your program to use these functions.
+ * Import `org.apache.spark.SparkContext._` at the top of your program to use these functions.
  */
 class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
   extends Logging
@@ -697,7 +697,6 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
   private[spark] def getValueClass() = implicitly[ClassManifest[V]].erasure
 }
 
-
 private[spark] object Manifests {
   val seqSeqManifest = classManifest[Seq[Seq[_]]]
 }
diff --git a/core/src/main/scala/org/apache/spark/rdd/ParallelCollectionRDD.scala b/core/src/main/scala/org/apache/spark/rdd/ParallelCollectionRDD.scala
index 8db3611054..6dbd4309aa 100644
--- a/core/src/main/scala/org/apache/spark/rdd/ParallelCollectionRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/ParallelCollectionRDD.scala
@@ -23,6 +23,8 @@ import scala.collection.Map
 import org.apache.spark._
 import java.io._
 import scala.Serializable
+import org.apache.spark.serializer.JavaSerializer
+import org.apache.spark.util.Utils
 
 private[spark] class ParallelCollectionPartition[T: ClassManifest](
     var rddId: Long,
diff --git a/core/src/main/scala/org/apache/spark/rdd/PartitionPruningRDD.scala b/core/src/main/scala/org/apache/spark/rdd/PartitionPruningRDD.scala
index 8e79a5c874..165cd412fc 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PartitionPruningRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PartitionPruningRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{NarrowDependency, RDD, SparkEnv, Partition, TaskContext}
+import org.apache.spark.{NarrowDependency, SparkEnv, Partition, TaskContext}
 
 
 class PartitionPruningRDDPartition(idx: Int, val parentSplit: Partition) extends Partition {
diff --git a/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
index 98498d5ddf..d5304ab0ae 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
@@ -25,7 +25,7 @@ import scala.collection.JavaConversions._
 import scala.collection.mutable.ArrayBuffer
 import scala.io.Source
 
-import org.apache.spark.{RDD, SparkEnv, Partition, TaskContext}
+import org.apache.spark.{SparkEnv, Partition, TaskContext}
 import org.apache.spark.broadcast.Broadcast
 
 
diff --git a/core/src/main/scala/org/apache/spark/RDD.scala b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
index 0d1f07f76c..e143ecd096 100644
--- a/core/src/main/scala/org/apache/spark/RDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import java.util.Random
 
@@ -37,37 +37,22 @@ import org.apache.spark.partial.BoundedDouble
 import org.apache.spark.partial.CountEvaluator
 import org.apache.spark.partial.GroupedCountEvaluator
 import org.apache.spark.partial.PartialResult
-import org.apache.spark.rdd.CoalescedRDD
-import org.apache.spark.rdd.CartesianRDD
-import org.apache.spark.rdd.FilteredRDD
-import org.apache.spark.rdd.FlatMappedRDD
-import org.apache.spark.rdd.GlommedRDD
-import org.apache.spark.rdd.MappedRDD
-import org.apache.spark.rdd.MapPartitionsRDD
-import org.apache.spark.rdd.MapPartitionsWithIndexRDD
-import org.apache.spark.rdd.PipedRDD
-import org.apache.spark.rdd.SampledRDD
-import org.apache.spark.rdd.ShuffledRDD
-import org.apache.spark.rdd.UnionRDD
-import org.apache.spark.rdd.ZippedRDD
-import org.apache.spark.rdd.ZippedPartitionsRDD2
-import org.apache.spark.rdd.ZippedPartitionsRDD3
-import org.apache.spark.rdd.ZippedPartitionsRDD4
 import org.apache.spark.storage.StorageLevel
-import org.apache.spark.util.BoundedPriorityQueue
+import org.apache.spark.util.{Utils, BoundedPriorityQueue}
 
-import SparkContext._
+import org.apache.spark.SparkContext._
+import org.apache.spark._
 
 /**
  * A Resilient Distributed Dataset (RDD), the basic abstraction in Spark. Represents an immutable,
  * partitioned collection of elements that can be operated on in parallel. This class contains the
  * basic operations available on all RDDs, such as `map`, `filter`, and `persist`. In addition,
- * [[org.apache.spark.PairRDDFunctions]] contains operations available only on RDDs of key-value pairs, such
- * as `groupByKey` and `join`; [[org.apache.spark.DoubleRDDFunctions]] contains operations available only on
- * RDDs of Doubles; and [[org.apache.spark.SequenceFileRDDFunctions]] contains operations available on RDDs
- * that can be saved as SequenceFiles. These operations are automatically available on any RDD of
- * the right type (e.g. RDD[(Int, Int)] through implicit conversions when you
- * `import org.apache.spark.SparkContext._`.
+ * [[org.apache.spark.rdd.PairRDDFunctions]] contains operations available only on RDDs of key-value
+ * pairs, such as `groupByKey` and `join`; [[org.apache.spark.rdd.DoubleRDDFunctions]] contains
+ * operations available only on RDDs of Doubles; and [[org.apache.spark.rdd.SequenceFileRDDFunctions]]
+ * contains operations available on RDDs that can be saved as SequenceFiles. These operations are
+ * automatically available on any RDD of the right type (e.g. RDD[(Int, Int)] through implicit
+ * conversions when you `import org.apache.spark.SparkContext._`.
  *
  * Internally, each RDD is characterized by five main properties:
  *
diff --git a/core/src/main/scala/org/apache/spark/RDDCheckpointData.scala b/core/src/main/scala/org/apache/spark/rdd/RDDCheckpointData.scala
index 0334de6924..6009a41570 100644
--- a/core/src/main/scala/org/apache/spark/RDDCheckpointData.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/RDDCheckpointData.scala
@@ -15,12 +15,13 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import org.apache.hadoop.fs.Path
 import org.apache.hadoop.conf.Configuration
-import rdd.{CheckpointRDD, CoalescedRDD}
-import scheduler.{ResultTask, ShuffleMapTask}
+
+import org.apache.spark.{Partition, SparkException, Logging}
+import org.apache.spark.scheduler.{ResultTask, ShuffleMapTask}
 
 /**
  * Enumeration to manage state transitions of an RDD through checkpointing
diff --git a/core/src/main/scala/org/apache/spark/rdd/SampledRDD.scala b/core/src/main/scala/org/apache/spark/rdd/SampledRDD.scala
index 1e8d89e912..2c5253ae30 100644
--- a/core/src/main/scala/org/apache/spark/rdd/SampledRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/SampledRDD.scala
@@ -22,7 +22,7 @@ import java.util.Random
 import cern.jet.random.Poisson
 import cern.jet.random.engine.DRand
 
-import org.apache.spark.{RDD, Partition, TaskContext}
+import org.apache.spark.{Partition, TaskContext}
 
 private[spark]
 class SampledRDDPartition(val prev: Partition, val seed: Int) extends Partition with Serializable {
diff --git a/core/src/main/scala/org/apache/spark/SequenceFileRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/SequenceFileRDDFunctions.scala
index d58fb4e4bc..5fe4676029 100644
--- a/core/src/main/scala/org/apache/spark/SequenceFileRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/SequenceFileRDDFunctions.scala
@@ -15,40 +15,22 @@
  * limitations under the License.
  */
 
-package org.apache.spark
-
-import java.io.EOFException
-import java.net.URL
-import java.io.ObjectInputStream
-import java.util.concurrent.atomic.AtomicLong
-import java.util.HashSet
-import java.util.Random
-import java.util.Date
-
-import scala.collection.mutable.ArrayBuffer
-import scala.collection.mutable.Map
-import scala.collection.mutable.HashMap
+package org.apache.spark.rdd
 
 import org.apache.hadoop.mapred.JobConf
-import org.apache.hadoop.mapred.OutputFormat
-import org.apache.hadoop.mapred.TextOutputFormat
 import org.apache.hadoop.mapred.SequenceFileOutputFormat
-import org.apache.hadoop.mapred.OutputCommitter
-import org.apache.hadoop.mapred.FileOutputCommitter
 import org.apache.hadoop.io.compress.CompressionCodec
 import org.apache.hadoop.io.Writable
-import org.apache.hadoop.io.NullWritable
-import org.apache.hadoop.io.BytesWritable
-import org.apache.hadoop.io.Text
 
 import org.apache.spark.SparkContext._
+import org.apache.spark.Logging
 
 /**
  * Extra functions available on RDDs of (key, value) pairs to create a Hadoop SequenceFile,
  * through an implicit conversion. Note that this can't be part of PairRDDFunctions because
  * we need more implicit parameters to convert our keys and values to Writable.
  *
- * Users should import `spark.SparkContext._` at the top of their program to use these functions.
+ * Import `org.apache.spark.SparkContext._` at the top of their program to use these functions.
  */
 class SequenceFileRDDFunctions[K <% Writable: ClassManifest, V <% Writable : ClassManifest](
     self: RDD[(K, V)])
diff --git a/core/src/main/scala/org/apache/spark/rdd/ShuffledRDD.scala b/core/src/main/scala/org/apache/spark/rdd/ShuffledRDD.scala
index f0e9ab8b80..9537152335 100644
--- a/core/src/main/scala/org/apache/spark/rdd/ShuffledRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/ShuffledRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{Dependency, Partitioner, RDD, SparkEnv, ShuffleDependency, Partition, TaskContext}
+import org.apache.spark.{Dependency, Partitioner, SparkEnv, ShuffleDependency, Partition, TaskContext}
 
 
 private[spark] class ShuffledRDDPartition(val idx: Int) extends Partition {
diff --git a/core/src/main/scala/org/apache/spark/rdd/SubtractedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/SubtractedRDD.scala
index 7369dfaa74..8c1a29dfff 100644
--- a/core/src/main/scala/org/apache/spark/rdd/SubtractedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/SubtractedRDD.scala
@@ -20,7 +20,6 @@ package org.apache.spark.rdd
 import java.util.{HashMap => JHashMap}
 import scala.collection.JavaConversions._
 import scala.collection.mutable.ArrayBuffer
-import org.apache.spark.RDD
 import org.apache.spark.Partitioner
 import org.apache.spark.Dependency
 import org.apache.spark.TaskContext
diff --git a/core/src/main/scala/org/apache/spark/rdd/UnionRDD.scala b/core/src/main/scala/org/apache/spark/rdd/UnionRDD.scala
index fd02476b62..ae8a9f36a6 100644
--- a/core/src/main/scala/org/apache/spark/rdd/UnionRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/UnionRDD.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.rdd
 
 import scala.collection.mutable.ArrayBuffer
-import org.apache.spark.{Dependency, RangeDependency, RDD, SparkContext, Partition, TaskContext}
+import org.apache.spark.{Dependency, RangeDependency, SparkContext, Partition, TaskContext}
 import java.io.{ObjectOutputStream, IOException}
 
 private[spark] class UnionPartition[T: ClassManifest](idx: Int, rdd: RDD[T], splitIndex: Int)
diff --git a/core/src/main/scala/org/apache/spark/rdd/ZippedPartitionsRDD.scala b/core/src/main/scala/org/apache/spark/rdd/ZippedPartitionsRDD.scala
index 5ae1db3e67..31e6fd519d 100644
--- a/core/src/main/scala/org/apache/spark/rdd/ZippedPartitionsRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/ZippedPartitionsRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{Utils, OneToOneDependency, RDD, SparkContext, Partition, TaskContext}
+import org.apache.spark.{OneToOneDependency, SparkContext, Partition, TaskContext}
 import java.io.{ObjectOutputStream, IOException}
 
 private[spark] class ZippedPartitionsPartition(
diff --git a/core/src/main/scala/org/apache/spark/rdd/ZippedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/ZippedRDD.scala
index 3bd00d291b..567b67dfee 100644
--- a/core/src/main/scala/org/apache/spark/rdd/ZippedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/ZippedRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import org.apache.spark.{Utils, OneToOneDependency, RDD, SparkContext, Partition, TaskContext}
+import org.apache.spark.{OneToOneDependency, SparkContext, Partition, TaskContext}
 import java.io.{ObjectOutputStream, IOException}
 
 
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 5ac700bbf4..92add5b073 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala
@@ -25,6 +25,7 @@ import java.util.concurrent.atomic.AtomicInteger
 import scala.collection.mutable.{ArrayBuffer, HashMap, HashSet, Map}
 
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.partial.{ApproximateActionListener, ApproximateEvaluator, PartialResult}
 import org.apache.spark.scheduler.cluster.TaskInfo
diff --git a/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala b/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala
index 5b07933eed..0d99670648 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala
@@ -23,6 +23,7 @@ import org.apache.spark.scheduler.cluster.TaskInfo
 import scala.collection.mutable.Map
 
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.executor.TaskMetrics
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala b/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
index 98ef4d1e63..c8b78bf00a 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
@@ -28,6 +28,7 @@ import scala.collection.mutable.{Map, HashMap, ListBuffer}
 import scala.io.Source

 

 import org.apache.spark._

+import org.apache.spark.rdd.RDD

 import org.apache.spark.executor.TaskMetrics

 import org.apache.spark.scheduler.cluster.TaskInfo

 

diff --git a/core/src/main/scala/org/apache/spark/scheduler/ResultTask.scala b/core/src/main/scala/org/apache/spark/scheduler/ResultTask.scala
index 2f157ccdd2..2b007cbe82 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/ResultTask.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/ResultTask.scala
@@ -17,11 +17,14 @@
 
 package org.apache.spark.scheduler
 
-import org.apache.spark._
 import java.io._
-import util.{MetadataCleaner, TimeStampedHashMap}
 import java.util.zip.{GZIPInputStream, GZIPOutputStream}
 
+import org.apache.spark._
+import org.apache.spark.rdd.RDD
+import org.apache.spark.rdd.RDDCheckpointData
+import org.apache.spark.util.{MetadataCleaner, TimeStampedHashMap}
+
 private[spark] object ResultTask {
 
   // A simple map between the stage id to the serialized byte array of a task.
diff --git a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala
index ca716b44e8..764775fede 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala
@@ -26,6 +26,8 @@ import org.apache.spark._
 import org.apache.spark.executor.ShuffleWriteMetrics
 import org.apache.spark.storage._
 import org.apache.spark.util.{TimeStampedHashMap, MetadataCleaner}
+import org.apache.spark.rdd.RDD
+import org.apache.spark.rdd.RDDCheckpointData
 
 
 private[spark] object ShuffleMapTask {
diff --git a/core/src/main/scala/org/apache/spark/scheduler/SparkListener.scala b/core/src/main/scala/org/apache/spark/scheduler/SparkListener.scala
index 3504424fa9..c3cf4b8907 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/SparkListener.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/SparkListener.scala
@@ -19,8 +19,8 @@ package org.apache.spark.scheduler
 
 import java.util.Properties
 import org.apache.spark.scheduler.cluster.TaskInfo
-import org.apache.spark.util.Distribution
-import org.apache.spark.{Logging, SparkContext, TaskEndReason, Utils}
+import org.apache.spark.util.{Utils, Distribution}
+import org.apache.spark.{Logging, SparkContext, TaskEndReason}
 import org.apache.spark.executor.TaskMetrics
 
 sealed trait SparkListenerEvents
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 87b1fe4e0c..aa293dc6b3 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/Stage.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/Stage.scala
@@ -17,9 +17,8 @@
 
 package org.apache.spark.scheduler
 
-import java.net.URI
-
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.storage.BlockManagerId
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/scheduler/TaskResult.scala b/core/src/main/scala/org/apache/spark/scheduler/TaskResult.scala
index 776675d28c..5c7e5bb977 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/TaskResult.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/TaskResult.scala
@@ -21,8 +21,9 @@ import java.io._
 
 import scala.collection.mutable.Map
 import org.apache.spark.executor.TaskMetrics
-import org.apache.spark.{Utils, SparkEnv}
+import org.apache.spark.{SparkEnv}
 import java.nio.ByteBuffer
+import org.apache.spark.util.Utils
 
 // Task result. Also contains updates to accumulator variables.
 // TODO: Use of distributed cache to return result is a hack to get around
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManager.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManager.scala
index a33307b83a..1b31c8c57e 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManager.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManager.scala
@@ -26,7 +26,7 @@ import scala.collection.mutable.HashSet
 import scala.math.max
 import scala.math.min
 
-import org.apache.spark.{FetchFailed, Logging, Resubmitted, SparkEnv, Success, TaskEndReason, TaskState, Utils}
+import org.apache.spark.{FetchFailed, Logging, Resubmitted, SparkEnv, Success, TaskEndReason, TaskState}
 import org.apache.spark.{ExceptionFailure, SparkException, TaskResultTooBigFailure}
 import org.apache.spark.TaskState.TaskState
 import org.apache.spark.scheduler._
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/SchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/SchedulerBackend.scala
index bde2f73df4..d57eb3276f 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/SchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/SchedulerBackend.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.scheduler.cluster
 
-import org.apache.spark.{SparkContext, Utils}
+import org.apache.spark.{SparkContext}
 
 /**
  * A backend interface for cluster scheduling systems that allows plugging in different ones under
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
index ac6dc7d879..d003bf1bba 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
@@ -17,10 +17,11 @@
 
 package org.apache.spark.scheduler.cluster
 
-import org.apache.spark.{Utils, Logging, SparkContext}
+import org.apache.spark.{Logging, SparkContext}
 import org.apache.spark.deploy.client.{Client, ClientListener}
 import org.apache.spark.deploy.{Command, ApplicationDescription}
 import scala.collection.mutable.HashMap
+import org.apache.spark.util.Utils
 
 private[spark] class SparkDeploySchedulerBackend(
     scheduler: ClusterScheduler,
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneClusterMessage.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneClusterMessage.scala
index 1cc5daf673..9c36d221f6 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneClusterMessage.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneClusterMessage.scala
@@ -20,8 +20,7 @@ package org.apache.spark.scheduler.cluster
 import java.nio.ByteBuffer
 
 import org.apache.spark.TaskState.TaskState
-import org.apache.spark.Utils
-import org.apache.spark.util.SerializableBuffer
+import org.apache.spark.util.{Utils, SerializableBuffer}
 
 
 private[spark] sealed trait StandaloneClusterMessage extends Serializable
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneSchedulerBackend.scala
index 3677a827e0..b4ea0be415 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/StandaloneSchedulerBackend.scala
@@ -28,8 +28,9 @@ import akka.remote.{RemoteClientShutdown, RemoteClientDisconnected, RemoteClient
 import akka.util.Duration
 import akka.util.duration._
 
-import org.apache.spark.{Utils, SparkException, Logging, TaskState}
+import org.apache.spark.{SparkException, Logging, TaskState}
 import org.apache.spark.scheduler.cluster.StandaloneClusterMessages._
+import org.apache.spark.util.Utils
 
 /**
  * A standalone scheduler backend, which waits for standalone executors to connect to it through
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/TaskInfo.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/TaskInfo.scala
index 7ce14be7fb..9685fb1a67 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/TaskInfo.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/TaskInfo.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.scheduler.cluster
 
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 /**
  * Information about a running task attempt inside a TaskSet.
diff --git a/core/src/main/scala/org/apache/spark/scheduler/local/LocalScheduler.scala b/core/src/main/scala/org/apache/spark/scheduler/local/LocalScheduler.scala
index f0ebe66d82..e8fa5e2f17 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/local/LocalScheduler.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/local/LocalScheduler.scala
@@ -34,6 +34,7 @@ import org.apache.spark.scheduler._
 import org.apache.spark.scheduler.cluster._
 import org.apache.spark.scheduler.cluster.SchedulingMode.SchedulingMode
 import akka.actor._
+import org.apache.spark.util.Utils
 
 /**
  * A FIFO or Fair TaskScheduler implementation that runs tasks locally in a thread pool. Optionally
diff --git a/core/src/main/scala/org/apache/spark/scheduler/mesos/CoarseMesosSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/mesos/CoarseMesosSchedulerBackend.scala
index f6a2feab28..3dbe61d706 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/mesos/CoarseMesosSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/mesos/CoarseMesosSchedulerBackend.scala
@@ -23,7 +23,7 @@ import org.apache.mesos.{Scheduler => MScheduler}
 import org.apache.mesos._
 import org.apache.mesos.Protos.{TaskInfo => MesosTaskInfo, TaskState => MesosTaskState, _}
 
-import org.apache.spark.{SparkException, Utils, Logging, SparkContext}
+import org.apache.spark.{SparkException, Logging, SparkContext}
 import scala.collection.mutable.{ArrayBuffer, HashMap, HashSet}
 import scala.collection.JavaConversions._
 import java.io.File
diff --git a/core/src/main/scala/org/apache/spark/scheduler/mesos/MesosSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/mesos/MesosSchedulerBackend.scala
index e002af1742..541f86e338 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/mesos/MesosSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/mesos/MesosSchedulerBackend.scala
@@ -23,7 +23,7 @@ import org.apache.mesos.{Scheduler => MScheduler}
 import org.apache.mesos._
 import org.apache.mesos.Protos.{TaskInfo => MesosTaskInfo, TaskState => MesosTaskState, _}
 
-import org.apache.spark.{SparkException, Utils, Logging, SparkContext}
+import org.apache.spark.{SparkException, Logging, SparkContext}
 import scala.collection.mutable.{ArrayBuffer, HashMap, HashSet}
 import scala.collection.JavaConversions._
 import java.io.File
@@ -31,6 +31,7 @@ import org.apache.spark.scheduler.cluster._
 import java.util.{ArrayList => JArrayList, List => JList}
 import java.util.Collections
 import org.apache.spark.TaskState
+import org.apache.spark.util.Utils
 
 /**
  * A SchedulerBackend for running fine-grained tasks on Mesos. Each Spark task is mapped to a
diff --git a/core/src/main/scala/org/apache/spark/JavaSerializer.scala b/core/src/main/scala/org/apache/spark/serializer/JavaSerializer.scala
index f43396cb6b..4de81617b1 100644
--- a/core/src/main/scala/org/apache/spark/JavaSerializer.scala
+++ b/core/src/main/scala/org/apache/spark/serializer/JavaSerializer.scala
@@ -15,12 +15,11 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.serializer
 
 import java.io._
 import java.nio.ByteBuffer
 
-import serializer.{Serializer, SerializerInstance, DeserializationStream, SerializationStream}
 import org.apache.spark.util.ByteBufferInputStream
 
 private[spark] class JavaSerializationStream(out: OutputStream) extends SerializationStream {
diff --git a/core/src/main/scala/org/apache/spark/KryoSerializer.scala b/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala
index db86e6db43..24ef204aa1 100644
--- a/core/src/main/scala/org/apache/spark/KryoSerializer.scala
+++ b/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala
@@ -15,17 +15,74 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.serializer
 
-import java.io._
 import java.nio.ByteBuffer
-import com.esotericsoftware.kryo.{Kryo, KryoException}
-import com.esotericsoftware.kryo.io.{Input => KryoInput, Output => KryoOutput}
+import java.io.{EOFException, InputStream, OutputStream}
+
 import com.esotericsoftware.kryo.serializers.{JavaSerializer => KryoJavaSerializer}
+import com.esotericsoftware.kryo.{KryoException, Kryo}
+import com.esotericsoftware.kryo.io.{Input => KryoInput, Output => KryoOutput}
 import com.twitter.chill.ScalaKryoInstantiator
-import serializer.{SerializerInstance, DeserializationStream, SerializationStream}
-import org.apache.spark.broadcast._
-import org.apache.spark.storage._
+
+import org.apache.spark.{SerializableWritable, Logging}
+import org.apache.spark.storage.{GetBlock, GotBlock, PutBlock, StorageLevel}
+
+import org.apache.spark.broadcast.HttpBroadcast
+
+/**
+ * A Spark serializer that uses the [[http://code.google.com/p/kryo/wiki/V1Documentation Kryo 1.x library]].
+ */
+class KryoSerializer extends org.apache.spark.serializer.Serializer with Logging {
+  private val bufferSize = System.getProperty("spark.kryoserializer.buffer.mb", "2").toInt * 1024 * 1024
+
+  def newKryoOutput() = new KryoOutput(bufferSize)
+
+  def newKryoInput() = new KryoInput(bufferSize)
+
+  def newKryo(): Kryo = {
+    val instantiator = new ScalaKryoInstantiator
+    val kryo = instantiator.newKryo()
+    val classLoader = Thread.currentThread.getContextClassLoader
+
+    // Register some commonly used classes
+    val toRegister: Seq[AnyRef] = Seq(
+      ByteBuffer.allocate(1),
+      StorageLevel.MEMORY_ONLY,
+      PutBlock("1", ByteBuffer.allocate(1), StorageLevel.MEMORY_ONLY),
+      GotBlock("1", ByteBuffer.allocate(1)),
+      GetBlock("1")
+    )
+
+    for (obj <- toRegister) kryo.register(obj.getClass)
+
+    // Allow sending SerializableWritable
+    kryo.register(classOf[SerializableWritable[_]], new KryoJavaSerializer())
+    kryo.register(classOf[HttpBroadcast[_]], new KryoJavaSerializer())
+
+    // Allow the user to register their own classes by setting spark.kryo.registrator
+    try {
+      Option(System.getProperty("spark.kryo.registrator")).foreach { regCls =>
+        logDebug("Running user registrator: " + regCls)
+        val reg = Class.forName(regCls, true, classLoader).newInstance().asInstanceOf[KryoRegistrator]
+        reg.registerClasses(kryo)
+      }
+    } catch {
+      case _: Exception => println("Failed to register spark.kryo.registrator")
+    }
+
+    kryo.setClassLoader(classLoader)
+
+    // Allow disabling Kryo reference tracking if user knows their object graphs don't have loops
+    kryo.setReferences(System.getProperty("spark.kryo.referenceTracking", "true").toBoolean)
+
+    kryo
+  }
+
+  def newInstance(): SerializerInstance = {
+    new KryoSerializerInstance(this)
+  }
+}
 
 private[spark]
 class KryoSerializationStream(kryo: Kryo, outStream: OutputStream) extends SerializationStream {
@@ -100,57 +157,3 @@ private[spark] class KryoSerializerInstance(ks: KryoSerializer) extends Serializ
 trait KryoRegistrator {
   def registerClasses(kryo: Kryo)
 }
-
-/**
- * A Spark serializer that uses the [[http://code.google.com/p/kryo/wiki/V1Documentation Kryo 1.x library]].
- */
-class KryoSerializer extends org.apache.spark.serializer.Serializer with Logging {
-  private val bufferSize = System.getProperty("spark.kryoserializer.buffer.mb", "2").toInt * 1024 * 1024
-
-  def newKryoOutput() = new KryoOutput(bufferSize)
-
-  def newKryoInput() = new KryoInput(bufferSize)
-
-  def newKryo(): Kryo = {
-    val instantiator = new ScalaKryoInstantiator
-    val kryo = instantiator.newKryo()
-    val classLoader = Thread.currentThread.getContextClassLoader
-
-    // Register some commonly used classes
-    val toRegister: Seq[AnyRef] = Seq(
-      ByteBuffer.allocate(1),
-      StorageLevel.MEMORY_ONLY,
-      PutBlock("1", ByteBuffer.allocate(1), StorageLevel.MEMORY_ONLY),
-      GotBlock("1", ByteBuffer.allocate(1)),
-      GetBlock("1")
-    )
-
-    for (obj <- toRegister) kryo.register(obj.getClass)
-
-    // Allow sending SerializableWritable
-    kryo.register(classOf[SerializableWritable[_]], new KryoJavaSerializer())
-    kryo.register(classOf[HttpBroadcast[_]], new KryoJavaSerializer())
-
-    // Allow the user to register their own classes by setting spark.kryo.registrator
-    try {
-      Option(System.getProperty("spark.kryo.registrator")).foreach { regCls =>
-        logDebug("Running user registrator: " + regCls)
-        val reg = Class.forName(regCls, true, classLoader).newInstance().asInstanceOf[KryoRegistrator]
-        reg.registerClasses(kryo)
-      }
-    } catch {
-      case _: Exception => println("Failed to register spark.kryo.registrator")
-    }
-
-    kryo.setClassLoader(classLoader)
-
-    // Allow disabling Kryo reference tracking if user knows their object graphs don't have loops
-    kryo.setReferences(System.getProperty("spark.kryo.referenceTracking", "true").toBoolean)
-
-    kryo
-  }
-
-  def newInstance(): SerializerInstance = {
-    new KryoSerializerInstance(this)
-  }
-}
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockFetcherIterator.scala b/core/src/main/scala/org/apache/spark/storage/BlockFetcherIterator.scala
index c91f0fc1ad..3aeda3879d 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockFetcherIterator.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockFetcherIterator.scala
@@ -27,12 +27,12 @@ import scala.collection.mutable.Queue
 import io.netty.buffer.ByteBuf
 
 import org.apache.spark.Logging
-import org.apache.spark.Utils
 import org.apache.spark.SparkException
 import org.apache.spark.network.BufferMessage
 import org.apache.spark.network.ConnectionManagerId
 import org.apache.spark.network.netty.ShuffleCopier
 import org.apache.spark.serializer.Serializer
+import org.apache.spark.util.Utils
 
 
 /**
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
index 3299ac98d5..60fdc5f2ee 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
@@ -29,11 +29,11 @@ import akka.util.duration._
 
 import it.unimi.dsi.fastutil.io.FastByteArrayOutputStream
 
-import org.apache.spark.{Logging, SparkEnv, SparkException, Utils}
+import org.apache.spark.{Logging, SparkEnv, SparkException}
 import org.apache.spark.io.CompressionCodec
 import org.apache.spark.network._
 import org.apache.spark.serializer.Serializer
-import org.apache.spark.util.{ByteBufferInputStream, IdGenerator, MetadataCleaner, TimeStampedHashMap}
+import org.apache.spark.util._
 
 import sun.nio.ch.DirectBuffer
 
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManagerId.scala b/core/src/main/scala/org/apache/spark/storage/BlockManagerId.scala
index a22a80decc..74207f59af 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManagerId.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManagerId.scala
@@ -19,7 +19,7 @@ package org.apache.spark.storage
 
 import java.io.{Externalizable, IOException, ObjectInput, ObjectOutput}
 import java.util.concurrent.ConcurrentHashMap
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 /**
  * This class represent an unique identifier for a BlockManager.
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManagerMasterActor.scala b/core/src/main/scala/org/apache/spark/storage/BlockManagerMasterActor.scala
index baa4a1da50..c7b23ab094 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManagerMasterActor.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManagerMasterActor.scala
@@ -28,8 +28,9 @@ import akka.pattern.ask
 import akka.util.Duration
 import akka.util.duration._
 
-import org.apache.spark.{Logging, Utils, SparkException}
+import org.apache.spark.{Logging, SparkException}
 import org.apache.spark.storage.BlockManagerMessages._
+import org.apache.spark.util.Utils
 
 
 /**
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 f4856020e5..678c38203c 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManagerWorker.scala
@@ -19,8 +19,9 @@ package org.apache.spark.storage
 
 import java.nio.ByteBuffer
 
-import org.apache.spark.{Logging, Utils}
+import org.apache.spark.{Logging}
 import org.apache.spark.network._
+import org.apache.spark.util.Utils
 
 /**
  * A network interface for BlockManager. Each slave should have one
diff --git a/core/src/main/scala/org/apache/spark/storage/DiskStore.scala b/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
index fd945e065c..fc25ef0fae 100644
--- a/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
@@ -28,12 +28,12 @@ import scala.collection.mutable.ArrayBuffer
 
 import it.unimi.dsi.fastutil.io.FastBufferedOutputStream
 
-import org.apache.spark.Utils
 import org.apache.spark.executor.ExecutorExitCode
 import org.apache.spark.serializer.{Serializer, SerializationStream}
 import org.apache.spark.Logging
 import org.apache.spark.network.netty.ShuffleSender
 import org.apache.spark.network.netty.PathResolver
+import org.apache.spark.util.Utils
 
 
 /**
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 828dc0f22d..3b3b2342fa 100644
--- a/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/MemoryStore.scala
@@ -19,9 +19,9 @@ package org.apache.spark.storage
 
 import java.util.LinkedHashMap
 import java.util.concurrent.ArrayBlockingQueue
-import org.apache.spark.{SizeEstimator, Utils}
 import java.nio.ByteBuffer
 import collection.mutable.ArrayBuffer
+import org.apache.spark.util.{SizeEstimator, Utils}
 
 /**
  * Stores blocks in memory, either as ArrayBuffers of deserialized Java objects or as
diff --git a/core/src/main/scala/org/apache/spark/storage/StorageUtils.scala b/core/src/main/scala/org/apache/spark/storage/StorageUtils.scala
index 0bba1dac54..2bb7715696 100644
--- a/core/src/main/scala/org/apache/spark/storage/StorageUtils.scala
+++ b/core/src/main/scala/org/apache/spark/storage/StorageUtils.scala
@@ -17,8 +17,9 @@
 
 package org.apache.spark.storage
 
-import org.apache.spark.{Utils, SparkContext}
+import org.apache.spark.{SparkContext}
 import BlockManagerMasterActor.BlockStatus
+import org.apache.spark.util.Utils
 
 private[spark]
 case class StorageStatus(blockManagerId: BlockManagerId, maxMem: Long,
diff --git a/core/src/main/scala/org/apache/spark/storage/ThreadingTest.scala b/core/src/main/scala/org/apache/spark/storage/ThreadingTest.scala
index 1d5afe9b08..f2ae8dd97d 100644
--- a/core/src/main/scala/org/apache/spark/storage/ThreadingTest.scala
+++ b/core/src/main/scala/org/apache/spark/storage/ThreadingTest.scala
@@ -19,9 +19,9 @@ package org.apache.spark.storage
 
 import akka.actor._
 
-import org.apache.spark.KryoSerializer
 import java.util.concurrent.ArrayBlockingQueue
 import util.Random
+import org.apache.spark.serializer.KryoSerializer
 
 /**
  * This class tests the BlockManager and MemoryStore for thread safety and
diff --git a/core/src/main/scala/org/apache/spark/ui/SparkUI.scala b/core/src/main/scala/org/apache/spark/ui/SparkUI.scala
index 4688effe0a..ad456ea565 100644
--- a/core/src/main/scala/org/apache/spark/ui/SparkUI.scala
+++ b/core/src/main/scala/org/apache/spark/ui/SparkUI.scala
@@ -21,12 +21,13 @@ import javax.servlet.http.HttpServletRequest
 
 import org.eclipse.jetty.server.{Handler, Server}
 
-import org.apache.spark.{Logging, SparkContext, SparkEnv, Utils}
+import org.apache.spark.{Logging, SparkContext, SparkEnv}
 import org.apache.spark.ui.env.EnvironmentUI
 import org.apache.spark.ui.exec.ExecutorsUI
 import org.apache.spark.ui.storage.BlockManagerUI
 import org.apache.spark.ui.jobs.JobProgressUI
 import org.apache.spark.ui.JettyUtils._
+import org.apache.spark.util.Utils
 
 /** Top level user interface for Spark */
 private[spark] class SparkUI(sc: SparkContext) extends Logging {
diff --git a/core/src/main/scala/org/apache/spark/ui/exec/ExecutorsUI.scala b/core/src/main/scala/org/apache/spark/ui/exec/ExecutorsUI.scala
index efe6b474e0..6e56c22d04 100644
--- a/core/src/main/scala/org/apache/spark/ui/exec/ExecutorsUI.scala
+++ b/core/src/main/scala/org/apache/spark/ui/exec/ExecutorsUI.scala
@@ -7,13 +7,14 @@ import scala.xml.Node
 
 import org.eclipse.jetty.server.Handler
 
-import org.apache.spark.{ExceptionFailure, Logging, Utils, SparkContext}
+import org.apache.spark.{ExceptionFailure, Logging, SparkContext}
 import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.scheduler.cluster.TaskInfo
 import org.apache.spark.scheduler.{SparkListenerTaskStart, SparkListenerTaskEnd, SparkListener}
 import org.apache.spark.ui.JettyUtils._
 import org.apache.spark.ui.Page.Executors
 import org.apache.spark.ui.UIUtils
+import org.apache.spark.util.Utils
 
 
 private[spark] class ExecutorsUI(val sc: SparkContext) {
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala b/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala
index ae02226300..86e0af0399 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala
@@ -3,7 +3,7 @@ package org.apache.spark.ui.jobs
 import scala.Seq
 import scala.collection.mutable.{ListBuffer, HashMap, HashSet}
 
-import org.apache.spark.{ExceptionFailure, SparkContext, Success, Utils}
+import org.apache.spark.{ExceptionFailure, SparkContext, Success}
 import org.apache.spark.scheduler._
 import org.apache.spark.scheduler.cluster.TaskInfo
 import org.apache.spark.executor.TaskMetrics
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressUI.scala b/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressUI.scala
index 1bb7638bd9..6aecef5120 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressUI.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/JobProgressUI.scala
@@ -29,11 +29,12 @@ import scala.Seq
 import scala.collection.mutable.{HashSet, ListBuffer, HashMap, ArrayBuffer}
 
 import org.apache.spark.ui.JettyUtils._
-import org.apache.spark.{ExceptionFailure, SparkContext, Success, Utils}
+import org.apache.spark.{ExceptionFailure, SparkContext, Success}
 import org.apache.spark.scheduler._
 import collection.mutable
 import org.apache.spark.scheduler.cluster.SchedulingMode
 import org.apache.spark.scheduler.cluster.SchedulingMode.SchedulingMode
+import org.apache.spark.util.Utils
 
 /** Web UI showing progress status of all jobs in the given SparkContext. */
 private[spark] class JobProgressUI(val sc: SparkContext) {
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala b/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
index 2fe85bc0cf..a9969ab1c0 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
@@ -25,8 +25,8 @@ import scala.xml.Node
 
 import org.apache.spark.ui.UIUtils._
 import org.apache.spark.ui.Page._
-import org.apache.spark.util.Distribution
-import org.apache.spark.{ExceptionFailure, Utils}
+import org.apache.spark.util.{Utils, Distribution}
+import org.apache.spark.{ExceptionFailure}
 import org.apache.spark.scheduler.cluster.TaskInfo
 import org.apache.spark.executor.TaskMetrics
 
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/StageTable.scala b/core/src/main/scala/org/apache/spark/ui/jobs/StageTable.scala
index beb0574548..71e58a977e 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/StageTable.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/StageTable.scala
@@ -5,9 +5,9 @@ import java.util.Date
 import scala.xml.Node
 import scala.collection.mutable.HashSet
 
-import org.apache.spark.Utils
 import org.apache.spark.scheduler.cluster.{SchedulingMode, TaskInfo}
 import org.apache.spark.scheduler.Stage
+import org.apache.spark.util.Utils
 
 
 /** Page showing list of all ongoing and recently finished stages */
diff --git a/core/src/main/scala/org/apache/spark/ui/storage/IndexPage.scala b/core/src/main/scala/org/apache/spark/ui/storage/IndexPage.scala
index 1eb4a7a85e..c3ec907370 100644
--- a/core/src/main/scala/org/apache/spark/ui/storage/IndexPage.scala
+++ b/core/src/main/scala/org/apache/spark/ui/storage/IndexPage.scala
@@ -22,9 +22,9 @@ import javax.servlet.http.HttpServletRequest
 import scala.xml.Node
 
 import org.apache.spark.storage.{RDDInfo, StorageUtils}
-import org.apache.spark.Utils
 import org.apache.spark.ui.UIUtils._
 import org.apache.spark.ui.Page._
+import org.apache.spark.util.Utils
 
 /** Page showing list of RDD's currently stored in the cluster */
 private[spark] class IndexPage(parent: BlockManagerUI) {
diff --git a/core/src/main/scala/org/apache/spark/ui/storage/RDDPage.scala b/core/src/main/scala/org/apache/spark/ui/storage/RDDPage.scala
index 37baf17f7a..43c1257677 100644
--- a/core/src/main/scala/org/apache/spark/ui/storage/RDDPage.scala
+++ b/core/src/main/scala/org/apache/spark/ui/storage/RDDPage.scala
@@ -21,11 +21,11 @@ import javax.servlet.http.HttpServletRequest
 
 import scala.xml.Node
 
-import org.apache.spark.Utils
 import org.apache.spark.storage.{StorageStatus, StorageUtils}
 import org.apache.spark.storage.BlockManagerMasterActor.BlockStatus
 import org.apache.spark.ui.UIUtils._
 import org.apache.spark.ui.Page._
+import org.apache.spark.util.Utils
 
 
 /** Page showing storage details for a given RDD */
diff --git a/core/src/main/scala/org/apache/spark/ClosureCleaner.scala b/core/src/main/scala/org/apache/spark/util/ClosureCleaner.scala
index 71d9e62d4f..7108595e3e 100644
--- a/core/src/main/scala/org/apache/spark/ClosureCleaner.scala
+++ b/core/src/main/scala/org/apache/spark/util/ClosureCleaner.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import java.lang.reflect.Field
 
@@ -25,6 +25,7 @@ import scala.collection.mutable.Set
 import org.objectweb.asm.{ClassReader, ClassVisitor, MethodVisitor, Type}
 import org.objectweb.asm.Opcodes._
 import java.io.{InputStream, IOException, ByteArrayOutputStream, ByteArrayInputStream, BufferedInputStream}
+import org.apache.spark.Logging
 
 private[spark] object ClosureCleaner extends Logging {
   // Get an ASM class reader for a given class from the JAR that loaded it
diff --git a/core/src/main/scala/org/apache/spark/util/MemoryParam.scala b/core/src/main/scala/org/apache/spark/util/MemoryParam.scala
index 0ee6707826..4869c9897a 100644
--- a/core/src/main/scala/org/apache/spark/util/MemoryParam.scala
+++ b/core/src/main/scala/org/apache/spark/util/MemoryParam.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.util
 
-import org.apache.spark.Utils
-
 /**
  * An extractor object for parsing JVM memory strings, such as "10g", into an Int representing
  * the number of megabytes. Supports the same formats as Utils.memoryStringToMb.
diff --git a/core/src/main/scala/org/apache/spark/SizeEstimator.scala b/core/src/main/scala/org/apache/spark/util/SizeEstimator.scala
index 4bfc837710..a25b37a2a9 100644
--- a/core/src/main/scala/org/apache/spark/SizeEstimator.scala
+++ b/core/src/main/scala/org/apache/spark/util/SizeEstimator.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import java.lang.reflect.Field
 import java.lang.reflect.Modifier
@@ -30,6 +30,7 @@ import java.lang.management.ManagementFactory
 import scala.collection.mutable.ArrayBuffer
 
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet
+import org.apache.spark.Logging
 
 /**
  * Estimates the sizes of Java objects (number of bytes of memory they occupy), for use in 
diff --git a/core/src/main/scala/org/apache/spark/Utils.scala b/core/src/main/scala/org/apache/spark/util/Utils.scala
index 1e17deb010..bb47fc0a2c 100644
--- a/core/src/main/scala/org/apache/spark/Utils.scala
+++ b/core/src/main/scala/org/apache/spark/util/Utils.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import java.io._
 import java.net.{InetAddress, URL, URI, NetworkInterface, Inet4Address, ServerSocket}
@@ -36,12 +36,13 @@ import org.apache.hadoop.fs.{Path, FileSystem, FileUtil}
 import org.apache.spark.serializer.{DeserializationStream, SerializationStream, SerializerInstance}
 import org.apache.spark.deploy.SparkHadoopUtil
 import java.nio.ByteBuffer
+import org.apache.spark.{SparkEnv, SparkException, Logging}
 
 
 /**
  * Various utility methods used by Spark.
  */
-private object Utils extends Logging {
+private[spark] object Utils extends Logging {
 
   /** Serialize an object using Java serialization */
   def serialize[T](o: T): Array[Byte] = {
diff --git a/core/src/test/scala/org/apache/spark/CheckpointSuite.scala b/core/src/test/scala/org/apache/spark/CheckpointSuite.scala
index 23b14f4245..d9103aebb7 100644
--- a/core/src/test/scala/org/apache/spark/CheckpointSuite.scala
+++ b/core/src/test/scala/org/apache/spark/CheckpointSuite.scala
@@ -22,6 +22,7 @@ import java.io.File
 import org.apache.spark.rdd._
 import org.apache.spark.SparkContext._
 import storage.StorageLevel
+import org.apache.spark.util.Utils
 
 class CheckpointSuite extends FunSuite with LocalSparkContext with Logging {
   initLogging()
diff --git a/core/src/test/scala/org/apache/spark/DriverSuite.scala b/core/src/test/scala/org/apache/spark/DriverSuite.scala
index b08aad1a6f..01a72d8401 100644
--- a/core/src/test/scala/org/apache/spark/DriverSuite.scala
+++ b/core/src/test/scala/org/apache/spark/DriverSuite.scala
@@ -26,6 +26,7 @@ import org.scalatest.FunSuite
 import org.scalatest.concurrent.Timeouts
 import org.scalatest.prop.TableDrivenPropertyChecks._
 import org.scalatest.time.SpanSugar._
+import org.apache.spark.util.Utils
 
 class DriverSuite extends FunSuite with Timeouts {
   test("driver should exit after finishing") {
diff --git a/core/src/test/scala/org/apache/spark/FailureSuite.scala b/core/src/test/scala/org/apache/spark/FailureSuite.scala
index ee89a7a387..af448fcb37 100644
--- a/core/src/test/scala/org/apache/spark/FailureSuite.scala
+++ b/core/src/test/scala/org/apache/spark/FailureSuite.scala
@@ -20,6 +20,7 @@ package org.apache.spark
 import org.scalatest.FunSuite
 
 import SparkContext._
+import org.apache.spark.util.NonSerializable
 
 // Common state shared by FailureSuite-launched tasks. We use a global object
 // for this because any local variables used in the task closures will rightfully
diff --git a/core/src/test/scala/org/apache/spark/PartitionPruningRDDSuite.scala b/core/src/test/scala/org/apache/spark/PartitionPruningRDDSuite.scala
index adbe805916..5a18dd13ff 100644
--- a/core/src/test/scala/org/apache/spark/PartitionPruningRDDSuite.scala
+++ b/core/src/test/scala/org/apache/spark/PartitionPruningRDDSuite.scala
@@ -2,7 +2,7 @@ package org.apache.spark
 
 import org.scalatest.FunSuite
 import org.apache.spark.SparkContext._
-import org.apache.spark.rdd.PartitionPruningRDD
+import org.apache.spark.rdd.{RDD, PartitionPruningRDD}
 
 
 class PartitionPruningRDDSuite extends FunSuite with SharedSparkContext {
diff --git a/core/src/test/scala/org/apache/spark/PartitioningSuite.scala b/core/src/test/scala/org/apache/spark/PartitioningSuite.scala
index 7669cf6fb1..7d938917f2 100644
--- a/core/src/test/scala/org/apache/spark/PartitioningSuite.scala
+++ b/core/src/test/scala/org/apache/spark/PartitioningSuite.scala
@@ -17,11 +17,14 @@
 
 package org.apache.spark
 
-import org.scalatest.FunSuite
+import scala.math.abs
 import scala.collection.mutable.ArrayBuffer
-import SparkContext._
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.SparkContext._
 import org.apache.spark.util.StatCounter
-import scala.math.abs
+import org.apache.spark.rdd.RDD
 
 class PartitioningSuite extends FunSuite with SharedSparkContext {
 
diff --git a/core/src/test/scala/org/apache/spark/ShuffleSuite.scala b/core/src/test/scala/org/apache/spark/ShuffleSuite.scala
index 357175e89e..db717865db 100644
--- a/core/src/test/scala/org/apache/spark/ShuffleSuite.scala
+++ b/core/src/test/scala/org/apache/spark/ShuffleSuite.scala
@@ -22,8 +22,9 @@ import org.scalatest.matchers.ShouldMatchers
 
 import org.apache.spark.SparkContext._
 import org.apache.spark.ShuffleSuite.NonJavaSerializableClass
-import org.apache.spark.rdd.{SubtractedRDD, CoGroupedRDD, OrderedRDDFunctions, ShuffledRDD}
+import org.apache.spark.rdd.{RDD, SubtractedRDD, CoGroupedRDD, OrderedRDDFunctions, ShuffledRDD}
 import org.apache.spark.util.MutablePair
+import org.apache.spark.serializer.KryoSerializer
 
 
 class ShuffleSuite extends FunSuite with ShouldMatchers with LocalSparkContext {
diff --git a/core/src/test/scala/org/apache/spark/PairRDDFunctionsSuite.scala b/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala
index f79752b34e..31f97fc139 100644
--- a/core/src/test/scala/org/apache/spark/PairRDDFunctionsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashSet
@@ -24,6 +24,7 @@ import org.scalatest.FunSuite
 
 import com.google.common.io.Files
 import org.apache.spark.SparkContext._
+import org.apache.spark.{Partitioner, SharedSparkContext}
 
 
 class PairRDDFunctionsSuite extends FunSuite with SharedSparkContext {
diff --git a/core/src/test/scala/org/apache/spark/RDDSuite.scala b/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala
index 342ba8adb2..adc971050e 100644
--- a/core/src/test/scala/org/apache/spark/RDDSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import scala.collection.mutable.HashMap
 import org.scalatest.FunSuite
@@ -24,6 +24,8 @@ import org.scalatest.time.{Span, Millis}
 import org.apache.spark.SparkContext._
 import org.apache.spark.rdd._
 import scala.collection.parallel.mutable
+import org.apache.spark._
+import org.apache.spark.rdd.CoalescedRDDPartition
 
 class RDDSuite extends FunSuite with SharedSparkContext {
 
diff --git a/core/src/test/scala/org/apache/spark/SortingSuite.scala b/core/src/test/scala/org/apache/spark/rdd/SortingSuite.scala
index f4fa9511dd..2f7bd370fc 100644
--- a/core/src/test/scala/org/apache/spark/SortingSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/SortingSuite.scala
@@ -15,12 +15,14 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import org.scalatest.FunSuite
 import org.scalatest.BeforeAndAfter
 import org.scalatest.matchers.ShouldMatchers
-import SparkContext._
+
+import org.apache.spark.{Logging, SharedSparkContext}
+import org.apache.spark.SparkContext._
 
 class SortingSuite extends FunSuite with SharedSparkContext with ShouldMatchers with Logging {
 
diff --git a/core/src/test/scala/org/apache/spark/scheduler/DAGSchedulerSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/DAGSchedulerSuite.scala
index 94df282b28..94f66c94c6 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/DAGSchedulerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/DAGSchedulerSuite.scala
@@ -24,7 +24,7 @@ import org.scalatest.BeforeAndAfter
 
 import org.apache.spark.LocalSparkContext
 import org.apache.spark.MapOutputTracker
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext
 import org.apache.spark.Partition
 import org.apache.spark.TaskContext
diff --git a/core/src/test/scala/org/apache/spark/scheduler/JobLoggerSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/JobLoggerSuite.scala
index f5b3e97222..cece60dda7 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/JobLoggerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/JobLoggerSuite.scala
@@ -19,11 +19,15 @@ package org.apache.spark.scheduler
 
 import java.util.Properties
 import java.util.concurrent.LinkedBlockingQueue
+
+import scala.collection.mutable
+
 import org.scalatest.FunSuite
 import org.scalatest.matchers.ShouldMatchers
-import scala.collection.mutable
+
 import org.apache.spark._
 import org.apache.spark.SparkContext._
+import org.apache.spark.rdd.RDD
 
 
 class JobLoggerSuite extends FunSuite with LocalSparkContext with ShouldMatchers {
diff --git a/core/src/test/scala/org/apache/spark/scheduler/TaskContextSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/TaskContextSuite.scala
index 0347cc02d7..e31a116a75 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/TaskContextSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/TaskContextSuite.scala
@@ -20,7 +20,7 @@ package org.apache.spark.scheduler
 import org.scalatest.FunSuite
 import org.scalatest.BeforeAndAfter
 import org.apache.spark.TaskContext
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext
 import org.apache.spark.Partition
 import org.apache.spark.LocalSparkContext
diff --git a/core/src/test/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManagerSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManagerSuite.scala
index a4f63baf3d..ff70a2cdf0 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManagerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/cluster/ClusterTaskSetManagerSuite.scala
@@ -26,7 +26,7 @@ import org.apache.spark._
 import org.apache.spark.scheduler._
 import org.apache.spark.executor.TaskMetrics
 import java.nio.ByteBuffer
-import org.apache.spark.util.FakeClock
+import org.apache.spark.util.{Utils, FakeClock}
 
 /**
  * A mock ClusterScheduler implementation that just remembers information about tasks started and
diff --git a/core/src/test/scala/org/apache/spark/KryoSerializerSuite.scala b/core/src/test/scala/org/apache/spark/serializer/KryoSerializerSuite.scala
index d7b23c93fe..0164dda0ba 100644
--- a/core/src/test/scala/org/apache/spark/KryoSerializerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/serializer/KryoSerializerSuite.scala
@@ -15,14 +15,15 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.serializer
 
 import scala.collection.mutable
 
-import org.scalatest.FunSuite
-import com.esotericsoftware.kryo._
+import com.esotericsoftware.kryo.Kryo
 
-import KryoTest._
+import org.scalatest.FunSuite
+import org.apache.spark.SharedSparkContext
+import org.apache.spark.serializer.KryoTest._
 
 class KryoSerializerSuite extends FunSuite with SharedSparkContext {
   test("basic types") {
@@ -103,7 +104,6 @@ class KryoSerializerSuite extends FunSuite with SharedSparkContext {
   }
 
   test("custom registrator") {
-    import KryoTest._
     System.setProperty("spark.kryo.registrator", classOf[MyRegistrator].getName)
 
     val ser = (new KryoSerializer).newInstance()
@@ -167,7 +167,7 @@ class KryoSerializerSuite extends FunSuite with SharedSparkContext {
   }
 
   override def beforeAll() {
-    System.setProperty("spark.serializer", "org.apache.spark.KryoSerializer")
+    System.setProperty("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
     System.setProperty("spark.kryo.registrator", classOf[MyRegistrator].getName)
     super.beforeAll()
   }
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 88ba10f2f2..038a9acb85 100644
--- a/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala
@@ -29,12 +29,8 @@ import org.scalatest.concurrent.Timeouts._
 import org.scalatest.matchers.ShouldMatchers._
 import org.scalatest.time.SpanSugar._
 
-import org.apache.spark.JavaSerializer
-import org.apache.spark.KryoSerializer
-import org.apache.spark.SizeEstimator
-import org.apache.spark.Utils
-import org.apache.spark.util.AkkaUtils
-import org.apache.spark.util.ByteBufferInputStream
+import org.apache.spark.util.{SizeEstimator, Utils, AkkaUtils, ByteBufferInputStream}
+import org.apache.spark.serializer.{JavaSerializer, KryoSerializer}
 
 
 class BlockManagerSuite extends FunSuite with BeforeAndAfter with PrivateMethodTester {
diff --git a/core/src/test/scala/org/apache/spark/ClosureCleanerSuite.scala b/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala
index 8494899b98..0ed366fb70 100644
--- a/core/src/test/scala/org/apache/spark/ClosureCleanerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala
@@ -15,13 +15,14 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import java.io.NotSerializableException
 
 import org.scalatest.FunSuite
+
+import org.apache.spark.SparkContext
 import org.apache.spark.LocalSparkContext._
-import SparkContext._
 
 class ClosureCleanerSuite extends FunSuite {
   test("closures inside an object") {
diff --git a/core/src/test/scala/org/apache/spark/SizeEstimatorSuite.scala b/core/src/test/scala/org/apache/spark/util/SizeEstimatorSuite.scala
index 214ac74898..4e40dcbdee 100644
--- a/core/src/test/scala/org/apache/spark/SizeEstimatorSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/SizeEstimatorSuite.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import org.scalatest.FunSuite
 import org.scalatest.BeforeAndAfterAll
diff --git a/core/src/test/scala/org/apache/spark/UtilsSuite.scala b/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala
index 3a908720a8..e2859caf58 100644
--- a/core/src/test/scala/org/apache/spark/UtilsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.util
 
 import com.google.common.base.Charsets
 import com.google.common.io.Files
diff --git a/docs/configuration.md b/docs/configuration.md
index 55df18b6fb..58e9434bdc 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -36,13 +36,13 @@ there are at least five properties that you will commonly want to control:
 </tr>
 <tr>
   <td>spark.serializer</td>
-  <td>org.apache.spark.JavaSerializer</td>
+  <td>org.apache.spark.serializer.<br />JavaSerializer</td>
   <td>
     Class to use for serializing objects that will be sent over the network or need to be cached
     in serialized form. The default of Java serialization works with any Serializable Java object but is
-    quite slow, so we recommend <a href="tuning.html">using <code>org.apache.spark.KryoSerializer</code>
+    quite slow, so we recommend <a href="tuning.html">using <code>org.apache.spark.serializer.KryoSerializer</code>
     and configuring Kryo serialization</a> when speed is necessary. Can be any subclass of
-    <a href="api/core/index.html#org.apache.spark.Serializer"><code>org.apache.spark.Serializer</code></a>.
+    <a href="api/core/index.html#org.apache.spark.serializer.Serializer"><code>org.apache.spark.Serializer</code></a>.
   </td>
 </tr>
 <tr>
@@ -51,7 +51,7 @@ there are at least five properties that you will commonly want to control:
   <td>
     If you use Kryo serialization, set this class to register your custom classes with Kryo.
     It should be set to a class that extends
-    <a href="api/core/index.html#org.apache.spark.KryoRegistrator"><code>KryoRegistrator</code></a>.
+    <a href="api/core/index.html#org.apache.spark.serializer.KryoRegistrator"><code>KryoRegistrator</code></a>.
     See the <a href="tuning.html#data-serialization">tuning guide</a> for more details.
   </td>
 </tr>
@@ -171,7 +171,7 @@ Apart from these, the following properties are also available, and may be useful
 </tr>
 <tr>
   <td>spark.closure.serializer</td>
-  <td>org.apache.spark.JavaSerializer</td>
+  <td>org.apache.spark.serializer.<br />JavaSerializer</td>
   <td>
     Serializer class to use for closures. Generally Java is fine unless your distributed functions
     (e.g. map functions) reference large objects in the driver program.
diff --git a/docs/quick-start.md b/docs/quick-start.md
index 8cbc55bed2..70c3df8095 100644
--- a/docs/quick-start.md
+++ b/docs/quick-start.md
@@ -109,7 +109,7 @@ We'll create a very simple Spark job in Scala. So simple, in fact, that it's nam
 {% highlight scala %}
 /*** SimpleJob.scala ***/
 import org.apache.spark.SparkContext
-import SparkContext._
+import org.apache.spark.SparkContext._
 
 object SimpleJob {
   def main(args: Array[String]) {
diff --git a/docs/scala-programming-guide.md b/docs/scala-programming-guide.md
index 2cf319a263..f7768e55fc 100644
--- a/docs/scala-programming-guide.md
+++ b/docs/scala-programming-guide.md
@@ -37,7 +37,7 @@ Finally, you need to import some Spark classes and implicit conversions into you
 
 {% highlight scala %}
 import org.apache.spark.SparkContext
-import SparkContext._
+import org.apache.spark.SparkContext._
 {% endhighlight %}
 
 # Initializing Spark
diff --git a/docs/tuning.md b/docs/tuning.md
index 3563d110c9..28d88a2659 100644
--- a/docs/tuning.md
+++ b/docs/tuning.md
@@ -38,17 +38,17 @@ in your operations) and performance. It provides two serialization libraries:
   `Serializable` types and requires you to *register* the classes you'll use in the program in advance
   for best performance.
 
-You can switch to using Kryo by calling `System.setProperty("spark.serializer", "org.apache.spark.KryoSerializer")`
+You can switch to using Kryo by calling `System.setProperty("spark.serializer", "org.apache.spark.serializer.KryoSerializer")`
 *before* creating your SparkContext. The only reason it is not the default is because of the custom
 registration requirement, but we recommend trying it in any network-intensive application.
 
 Finally, to register your classes with Kryo, create a public class that extends
-[`org.apache.spark.KryoRegistrator`](api/core/index.html#org.apache.spark.KryoRegistrator) and set the
+[`org.apache.spark.serializer.KryoRegistrator`](api/core/index.html#org.apache.spark.serializer.KryoRegistrator) and set the
 `spark.kryo.registrator` system property to point to it, as follows:
 
 {% highlight scala %}
 import com.esotericsoftware.kryo.Kryo
-import org.apache.spark.KryoRegistrator
+import org.apache.spark.serializer.KryoRegistrator
 
 class MyRegistrator extends KryoRegistrator {
   override def registerClasses(kryo: Kryo) {
@@ -58,7 +58,7 @@ class MyRegistrator extends KryoRegistrator {
 }
 
 // Make sure to set these properties *before* creating a SparkContext!
-System.setProperty("spark.serializer", "org.apache.spark.KryoSerializer")
+System.setProperty("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
 System.setProperty("spark.kryo.registrator", "mypackage.MyRegistrator")
 val sc = new SparkContext(...)
 {% endhighlight %}
@@ -217,7 +217,7 @@ enough. Spark automatically sets the number of "map" tasks to run on each file a
 (though you can control it through optional parameters to `SparkContext.textFile`, etc), and for
 distributed "reduce" operations, such as `groupByKey` and `reduceByKey`, it uses the largest
 parent RDD's number of partitions. You can pass the level of parallelism as a second argument
-(see the [`spark.PairRDDFunctions`](api/core/index.html#org.apache.spark.PairRDDFunctions) documentation),
+(see the [`spark.PairRDDFunctions`](api/core/index.html#org.apache.spark.rdd.PairRDDFunctions) documentation),
 or set the system property `spark.default.parallelism` to change the default.
 In general, we recommend 2-3 tasks per CPU core in your cluster.
 
diff --git a/examples/src/main/scala/org/apache/spark/examples/bagel/PageRankUtils.scala b/examples/src/main/scala/org/apache/spark/examples/bagel/PageRankUtils.scala
index b190e83c4d..cfafbaf23e 100644
--- a/examples/src/main/scala/org/apache/spark/examples/bagel/PageRankUtils.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/bagel/PageRankUtils.scala
@@ -19,6 +19,7 @@ package org.apache.spark.examples.bagel
 
 import org.apache.spark._
 import org.apache.spark.SparkContext._
+import org.apache.spark.serializer.KryoRegistrator
 
 import org.apache.spark.bagel._
 import org.apache.spark.bagel.Bagel._
diff --git a/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRank.scala b/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRank.scala
index b1f606e48e..72b5c7b88e 100644
--- a/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRank.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRank.scala
@@ -37,7 +37,7 @@ object WikipediaPageRank {
       System.exit(-1)
     }
 
-    System.setProperty("spark.serializer", "org.apache.spark.KryoSerializer")
+    System.setProperty("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
     System.setProperty("spark.kryo.registrator", classOf[PRKryoRegistrator].getName)
 
     val inputFile = args(0)
diff --git a/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRankStandalone.scala b/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRankStandalone.scala
index 3bfa48eaf3..ddf6855325 100644
--- a/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRankStandalone.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/bagel/WikipediaPageRankStandalone.scala
@@ -17,19 +17,16 @@
 
 package org.apache.spark.examples.bagel
 
-import org.apache.spark._
-import serializer.{DeserializationStream, SerializationStream, SerializerInstance}
-import org.apache.spark.SparkContext._
-
-import org.apache.spark.bagel._
-import org.apache.spark.bagel.Bagel._
-
-import scala.xml.{XML,NodeSeq}
+import java.io.{InputStream, OutputStream, DataInputStream, DataOutputStream}
+import java.nio.ByteBuffer
 
 import scala.collection.mutable.ArrayBuffer
+import scala.xml.{XML, NodeSeq}
 
-import java.io.{InputStream, OutputStream, DataInputStream, DataOutputStream}
-import java.nio.ByteBuffer
+import org.apache.spark._
+import org.apache.spark.serializer.{DeserializationStream, SerializationStream, SerializerInstance}
+import org.apache.spark.SparkContext._
+import org.apache.spark.rdd.RDD
 
 object WikipediaPageRankStandalone {
   def main(args: Array[String]) {
diff --git a/examples/src/main/scala/org/apache/spark/streaming/examples/QueueStream.scala b/examples/src/main/scala/org/apache/spark/streaming/examples/QueueStream.scala
index 822da8c9b5..fad512eeba 100644
--- a/examples/src/main/scala/org/apache/spark/streaming/examples/QueueStream.scala
+++ b/examples/src/main/scala/org/apache/spark/streaming/examples/QueueStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.examples
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.{Seconds, StreamingContext}
 import org.apache.spark.streaming.StreamingContext._
 
diff --git a/examples/src/main/scala/org/apache/spark/streaming/examples/RawNetworkGrep.scala b/examples/src/main/scala/org/apache/spark/streaming/examples/RawNetworkGrep.scala
index 2e3d9ccf00..0b45c30d20 100644
--- a/examples/src/main/scala/org/apache/spark/streaming/examples/RawNetworkGrep.scala
+++ b/examples/src/main/scala/org/apache/spark/streaming/examples/RawNetworkGrep.scala
@@ -28,7 +28,7 @@ import org.apache.spark.streaming.util.RawTextHelper
  * lines have the word 'the' in them. This is useful for benchmarking purposes. This
  * will only work with spark.streaming.util.RawTextSender running on all worker nodes
  * and with Spark using Kryo serialization (set Java property "spark.serializer" to
- * "org.apache.spark.KryoSerializer").
+ * "org.apache.spark.serializer.KryoSerializer").
  * Usage: RawNetworkGrep <master> <numStreams> <host> <port> <batchMillis>
  *   <master> is the Spark master URL
  *   <numStream> is the number rawNetworkStreams, which should be same as number
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/classification/ClassificationModel.scala b/mllib/src/main/scala/org/apache/spark/mllib/classification/ClassificationModel.scala
index 4f4a7f5296..60cb44ce89 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/classification/ClassificationModel.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/classification/ClassificationModel.scala
@@ -1,6 +1,6 @@
 package org.apache.spark.mllib.classification
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 trait ClassificationModel extends Serializable {
   /**
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/classification/LogisticRegression.scala b/mllib/src/main/scala/org/apache/spark/mllib/classification/LogisticRegression.scala
index 91bb50c829..50aede9c07 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/classification/LogisticRegression.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/classification/LogisticRegression.scala
@@ -19,7 +19,8 @@ package org.apache.spark.mllib.classification
 
 import scala.math.round
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 import org.apache.spark.mllib.regression._
 import org.apache.spark.mllib.util.MLUtils
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/classification/SVM.scala b/mllib/src/main/scala/org/apache/spark/mllib/classification/SVM.scala
index c92c7cc3f3..3511e24bce 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/classification/SVM.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/classification/SVM.scala
@@ -19,7 +19,8 @@ package org.apache.spark.mllib.classification
 
 import scala.math.signum
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 import org.apache.spark.mllib.regression._
 import org.apache.spark.mllib.util.MLUtils
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeans.scala b/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeans.scala
index 2c3db099fa..edbf77dbcc 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeans.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeans.scala
@@ -20,8 +20,9 @@ package org.apache.spark.mllib.clustering
 import scala.collection.mutable.ArrayBuffer
 import scala.util.Random
 
-import org.apache.spark.{SparkContext, RDD}
+import org.apache.spark.SparkContext
 import org.apache.spark.SparkContext._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.Logging
 import org.apache.spark.mllib.util.MLUtils
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeansModel.scala b/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeansModel.scala
index d1fe5d138d..cfc81c985a 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeansModel.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/clustering/KMeansModel.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.mllib.clustering
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 import org.apache.spark.mllib.util.MLUtils
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/optimization/GradientDescent.scala b/mllib/src/main/scala/org/apache/spark/mllib/optimization/GradientDescent.scala
index b62c9b3340..b77364e08d 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/optimization/GradientDescent.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/optimization/GradientDescent.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.optimization
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.{Logging, SparkContext}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 
 import org.jblas.DoubleMatrix
@@ -29,8 +30,9 @@ import scala.collection.mutable.ArrayBuffer
  * @param gradient Gradient function to be used.
  * @param updater Updater to be used to update weights after every iteration.
  */
-class GradientDescent(var gradient: Gradient, var updater: Updater) extends Optimizer {
-
+class GradientDescent(var gradient: Gradient, var updater: Updater)
+  extends Optimizer with Logging
+{
   private var stepSize: Double = 1.0
   private var numIterations: Int = 100
   private var regParam: Double = 0.0
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/optimization/Optimizer.scala b/mllib/src/main/scala/org/apache/spark/mllib/optimization/Optimizer.scala
index 50059d385d..94d30b56f2 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/optimization/Optimizer.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/optimization/Optimizer.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.mllib.optimization
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 trait Optimizer {
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/recommendation/ALS.scala b/mllib/src/main/scala/org/apache/spark/mllib/recommendation/ALS.scala
index 218217acfe..be002d02bc 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/recommendation/ALS.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/recommendation/ALS.scala
@@ -21,9 +21,10 @@ import scala.collection.mutable.{ArrayBuffer, BitSet}
 import scala.util.Random
 import scala.util.Sorting
 
-import org.apache.spark.{HashPartitioner, Partitioner, SparkContext, RDD}
+import org.apache.spark.{HashPartitioner, Partitioner, SparkContext}
 import org.apache.spark.storage.StorageLevel
-import org.apache.spark.KryoRegistrator
+import org.apache.spark.rdd.RDD
+import org.apache.spark.serializer.KryoRegistrator
 import org.apache.spark.SparkContext._
 
 import com.esotericsoftware.kryo.Kryo
@@ -432,7 +433,7 @@ object ALS {
     val (master, ratingsFile, rank, iters, outputDir) =
       (args(0), args(1), args(2).toInt, args(3).toInt, args(4))
     val blocks = if (args.length == 6) args(5).toInt else -1
-    System.setProperty("spark.serializer", "org.apache.spark.KryoSerializer")
+    System.setProperty("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
     System.setProperty("spark.kryo.registrator", classOf[ALSRegistrator].getName)
     System.setProperty("spark.kryo.referenceTracking", "false")
     System.setProperty("spark.kryoserializer.buffer.mb", "8")
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/recommendation/MatrixFactorizationModel.scala b/mllib/src/main/scala/org/apache/spark/mllib/recommendation/MatrixFactorizationModel.scala
index ae9fe48aec..af43d89c70 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/recommendation/MatrixFactorizationModel.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/recommendation/MatrixFactorizationModel.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.mllib.recommendation
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 
 import org.jblas._
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
index 06015110ac..f98b0b536d 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.regression
 
-import org.apache.spark.{Logging, RDD, SparkException}
+import org.apache.spark.{Logging, SparkException}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 
 import org.jblas.DoubleMatrix
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/Lasso.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/Lasso.scala
index df3beb1959..d959695325 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/Lasso.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/Lasso.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.regression
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.{Logging, SparkContext}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 import org.apache.spark.mllib.util.MLUtils
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/LinearRegression.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/LinearRegression.scala
index 71f968471c..ae95ea24fc 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/LinearRegression.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/LinearRegression.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.regression
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.{Logging, SparkContext}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 import org.apache.spark.mllib.util.MLUtils
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/RegressionModel.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/RegressionModel.scala
index 8dd325efc0..423afc32d6 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/RegressionModel.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/RegressionModel.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.mllib.regression
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 trait RegressionModel extends Serializable {
   /**
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/RidgeRegression.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/RidgeRegression.scala
index 228ab9e4e8..b29508d2b9 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/RidgeRegression.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/RidgeRegression.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.regression
 
-import org.apache.spark.{Logging, RDD, SparkContext}
+import org.apache.spark.{Logging, SparkContext}
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.optimization._
 import org.apache.spark.mllib.util.MLUtils
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/DataValidators.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/DataValidators.scala
index 7fd4623071..8b55bce7c4 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/DataValidators.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/DataValidators.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.util
 
-import org.apache.spark.{RDD, Logging}
+import org.apache.spark.Logging
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.regression.LabeledPoint
 
 /**
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/KMeansDataGenerator.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/KMeansDataGenerator.scala
index 6500d47183..9109189dff 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/KMeansDataGenerator.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/KMeansDataGenerator.scala
@@ -19,7 +19,8 @@ package org.apache.spark.mllib.util
 
 import scala.util.Random
 
-import org.apache.spark.{RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 
 /**
  * Generate test data for KMeans. This class first chooses k cluster centers
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/LinearDataGenerator.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/LinearDataGenerator.scala
index 4c49d484b4..bc5045fb05 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/LinearDataGenerator.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/LinearDataGenerator.scala
@@ -22,7 +22,8 @@ import scala.util.Random
 
 import org.jblas.DoubleMatrix
 
-import org.apache.spark.{RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.regression.LabeledPoint
 import org.apache.spark.mllib.regression.LabeledPoint
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/LogisticRegressionDataGenerator.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/LogisticRegressionDataGenerator.scala
index f553298fc5..52c4a71d62 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/LogisticRegressionDataGenerator.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/LogisticRegressionDataGenerator.scala
@@ -19,7 +19,8 @@ package org.apache.spark.mllib.util
 
 import scala.util.Random
 
-import org.apache.spark.{RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.regression.LabeledPoint
 
 /**
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/MFDataGenerator.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/MFDataGenerator.scala
index 7eb69ae81c..5aec867257 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/MFDataGenerator.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/MFDataGenerator.scala
@@ -21,7 +21,8 @@ import scala.util.Random
 
 import org.jblas.DoubleMatrix
 
-import org.apache.spark.{RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.util.MLUtils
 
 /**
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
index 0aeafbe23c..d91b74c3ac 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.mllib.util
 
-import org.apache.spark.{RDD, SparkContext}
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 
 import org.jblas.DoubleMatrix
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/SVMDataGenerator.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/SVMDataGenerator.scala
index d3f191b05b..6e9f667635 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/SVMDataGenerator.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/SVMDataGenerator.scala
@@ -2,9 +2,10 @@ package org.apache.spark.mllib.util
 
 import scala.util.Random
 
-import org.apache.spark.{RDD, SparkContext}
-
 import org.jblas.DoubleMatrix
+
+import org.apache.spark.SparkContext
+import org.apache.spark.rdd.RDD
 import org.apache.spark.mllib.regression.LabeledPoint
 
 /**
diff --git a/python/pyspark/context.py b/python/pyspark/context.py
index 906e9221a1..8fbf296509 100644
--- a/python/pyspark/context.py
+++ b/python/pyspark/context.py
@@ -114,9 +114,9 @@ class SparkContext(object):
             self.addPyFile(path)
 
         # Create a temporary directory inside spark.local.dir:
-        local_dir = self._jvm.org.apache.spark.Utils.getLocalDir()
+        local_dir = self._jvm.org.apache.spark.util.Utils.getLocalDir()
         self._temp_dir = \
-            self._jvm.org.apache.spark.Utils.createTempDir(local_dir).getAbsolutePath()
+            self._jvm.org.apache.spark.util.Utils.createTempDir(local_dir).getAbsolutePath()
 
     @property
     def defaultParallelism(self):
diff --git a/repl/src/main/scala/org/apache/spark/repl/SparkIMain.scala b/repl/src/main/scala/org/apache/spark/repl/SparkIMain.scala
index 7e244e48a2..e6e35c9b5d 100644
--- a/repl/src/main/scala/org/apache/spark/repl/SparkIMain.scala
+++ b/repl/src/main/scala/org/apache/spark/repl/SparkIMain.scala
@@ -28,7 +28,7 @@ import scala.reflect.NameTransformer
 import SparkIMain._
 
 import org.apache.spark.HttpServer
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 import org.apache.spark.SparkEnv
 
 /** An interpreter for Scala code.
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
index 362247cc38..80da6bd30b 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
@@ -23,7 +23,8 @@ import org.apache.spark.util.MetadataCleaner
 
 //import Time._
 
-import org.apache.spark.{RDD, Logging}
+import org.apache.spark.Logging
+import org.apache.spark.rdd.RDD
 import org.apache.spark.storage.StorageLevel
 
 import scala.collection.mutable.ArrayBuffer
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/Duration.scala b/streaming/src/main/scala/org/apache/spark/streaming/Duration.scala
index 290ad37812..6bf275f5af 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/Duration.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/Duration.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming
 
-import org.apache.spark.Utils
+import org.apache.spark.util.Utils
 
 case class Duration (private val millis: Long) {
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala b/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
index d8a7381e87..757bc98981 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
@@ -22,8 +22,9 @@ import org.apache.spark.streaming.dstream.{ReducedWindowedDStream, StateDStream}
 import org.apache.spark.streaming.dstream.{CoGroupedDStream, ShuffledDStream}
 import org.apache.spark.streaming.dstream.{MapValuedDStream, FlatMapValuedDStream}
 
-import org.apache.spark.{Manifests, RDD, Partitioner, HashPartitioner}
+import org.apache.spark.{Partitioner, HashPartitioner}
 import org.apache.spark.SparkContext._
+import org.apache.spark.rdd.{Manifests, RDD, PairRDDFunctions}
 import org.apache.spark.storage.StorageLevel
 
 import scala.collection.mutable.ArrayBuffer
@@ -101,8 +102,8 @@ extends Serializable {
 
   /**
    * Combine elements of each key in DStream's RDDs using custom functions. This is similar to the
-   * combineByKey for RDDs. Please refer to combineByKey in [[org.apache.spark.PairRDDFunctions]] for more
-   * information.
+   * combineByKey for RDDs. Please refer to combineByKey in
+   * [[org.apache.spark.rdd.PairRDDFunctions]] for more information.
    */
   def combineByKey[C: ClassManifest](
     createCombiner: V => C,
@@ -379,7 +380,7 @@ extends Serializable {
   /**
    * Return a new "state" DStream where the state for each key is updated by applying
    * the given function on the previous state of the key and the new values of each key.
-   * [[org.apache.spark.Paxrtitioner]] is used to control the partitioning of each RDD.
+   * [[org.apache.spark.Partitioner]] is used to control the partitioning of each RDD.
    * @param updateFunc State update function. If `this` function returns None, then
    *                   corresponding state key-value pair will be eliminated. Note, that
    *                   this function may generate a different a tuple with a different key
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala b/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
index 3852ac2dab..878725c705 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
@@ -24,6 +24,7 @@ import akka.zeromq.Subscribe
 import org.apache.spark.streaming.dstream._
 
 import org.apache.spark._
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.receivers.ActorReceiver
 import org.apache.spark.streaming.receivers.ReceiverSupervisorStrategy
 import org.apache.spark.streaming.receivers.ZeroMQReceiver
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStream.scala
index f8c8d8ece1..d1932b6b05 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStream.scala
@@ -21,7 +21,7 @@ import org.apache.spark.streaming.{Duration, Time, DStream}
 import org.apache.spark.api.java.function.{Function => JFunction}
 import org.apache.spark.api.java.JavaRDD
 import org.apache.spark.storage.StorageLevel
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 /**
  * A Discretized Stream (DStream), the basic abstraction in Spark Streaming, is a continuous
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
index 2e6fe9a9c4..459695b7ca 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
@@ -26,7 +26,7 @@ import org.apache.spark.streaming._
 import org.apache.spark.api.java.{JavaPairRDD, JavaRDDLike, JavaRDD}
 import org.apache.spark.api.java.function.{Function2 => JFunction2, Function => JFunction, _}
 import java.util
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import JavaDStream._
 
 trait JavaDStreamLike[T, This <: JavaDStreamLike[T, This, R], R <: JavaRDDLike[T, R]]
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaPairDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaPairDStream.scala
index c203dccd17..978fca33ad 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaPairDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaPairDStream.scala
@@ -25,14 +25,15 @@ import scala.collection.JavaConversions._
 import org.apache.spark.streaming._
 import org.apache.spark.streaming.StreamingContext._
 import org.apache.spark.api.java.function.{Function => JFunction, Function2 => JFunction2}
-import org.apache.spark.{RDD, Partitioner}
+import org.apache.spark.Partitioner
 import org.apache.hadoop.mapred.{JobConf, OutputFormat}
 import org.apache.hadoop.mapreduce.{OutputFormat => NewOutputFormat}
 import org.apache.hadoop.conf.Configuration
 import org.apache.spark.api.java.{JavaUtils, JavaRDD, JavaPairRDD}
 import org.apache.spark.storage.StorageLevel
 import com.google.common.base.Optional
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
+import org.apache.spark.rdd.PairRDDFunctions
 
 class JavaPairDStream[K, V](val dstream: DStream[(K, V)])(
     implicit val kManifiest: ClassManifest[K],
@@ -147,7 +148,7 @@ class JavaPairDStream[K, V](val dstream: DStream[(K, V)])(
 
   /**
    * Combine elements of each key in DStream's RDDs using custom function. This is similar to the
-   * combineByKey for RDDs. Please refer to combineByKey in [[org.apache.spark.PairRDDFunctions]] for more
+   * combineByKey for RDDs. Please refer to combineByKey in [[PairRDDFunctions]] for more
    * information.
    */
   def combineByKey[C](createCombiner: JFunction[V, C],
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
index f10beb1db3..54ba3e6025 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
@@ -17,23 +17,26 @@
 
 package org.apache.spark.streaming.api.java
 
-import org.apache.spark.streaming._
-import receivers.{ActorReceiver, ReceiverSupervisorStrategy}
-import org.apache.spark.streaming.dstream._
-import org.apache.spark.storage.StorageLevel
-import org.apache.spark.api.java.function.{Function => JFunction, Function2 => JFunction2}
-import org.apache.spark.api.java.{JavaSparkContext, JavaRDD}
+import java.lang.{Long => JLong, Integer => JInt}
+import java.io.InputStream
+import java.util.{Map => JMap}
+
+import scala.collection.JavaConversions._
+
 import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
 import twitter4j.Status
 import akka.actor.Props
 import akka.actor.SupervisorStrategy
 import akka.zeromq.Subscribe
-import scala.collection.JavaConversions._
-import java.lang.{Long => JLong, Integer => JInt}
-import java.io.InputStream
-import java.util.{Map => JMap}
 import twitter4j.auth.Authorization
-import org.apache.spark.RDD
+
+import org.apache.spark.rdd.RDD
+import org.apache.spark.storage.StorageLevel
+import org.apache.spark.api.java.function.{Function => JFunction, Function2 => JFunction2}
+import org.apache.spark.api.java.{JavaSparkContext, JavaRDD}
+import org.apache.spark.streaming._
+import org.apache.spark.streaming.dstream._
+import org.apache.spark.streaming.receivers.{ActorReceiver, ReceiverSupervisorStrategy}
 
 /**
  * A StreamingContext is the main entry point for Spark Streaming functionality. Besides the basic
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/CoGroupedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/CoGroupedDStream.scala
index 4a9d82211f..4eddc755b9 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/CoGroupedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/CoGroupedDStream.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.{RDD, Partitioner}
+import org.apache.spark.Partitioner
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.CoGroupedRDD
 import org.apache.spark.streaming.{Time, DStream, Duration}
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ConstantInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ConstantInputDStream.scala
index 35cc4cb396..a9a05c9981 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ConstantInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ConstantInputDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.{Time, StreamingContext}
 
 /**
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
index 1c265ed972..fea0573b77 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.UnionRDD
 import org.apache.spark.streaming.{DStreamCheckpointData, StreamingContext, Time}
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FilteredDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FilteredDStream.scala
index 3166c68760..91ee2c1a36 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FilteredDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FilteredDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 private[streaming]
 class FilteredDStream[T: ClassManifest](
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMapValuedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMapValuedDStream.scala
index 21950ad6ac..ca7d7ca49e 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMapValuedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMapValuedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 
 private[streaming]
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMappedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMappedDStream.scala
index 8377cfe60c..b37966f9a7 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMappedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlatMappedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 private[streaming]
 class FlatMappedDStream[T: ClassManifest, U: ClassManifest](
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlumeInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlumeInputDStream.scala
index 3fb443143c..18de772946 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlumeInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FlumeInputDStream.scala
@@ -17,10 +17,11 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.streaming.StreamingContext
+import java.net.InetSocketAddress
+import java.io.{ObjectInput, ObjectOutput, Externalizable}
+import java.nio.ByteBuffer
 
-import org.apache.spark.Utils
-import org.apache.spark.storage.StorageLevel
+import scala.collection.JavaConversions._
 
 import org.apache.flume.source.avro.AvroSourceProtocol
 import org.apache.flume.source.avro.AvroFlumeEvent
@@ -28,11 +29,9 @@ import org.apache.flume.source.avro.Status
 import org.apache.avro.ipc.specific.SpecificResponder
 import org.apache.avro.ipc.NettyServer
 
-import scala.collection.JavaConversions._
-
-import java.net.InetSocketAddress
-import java.io.{ObjectInput, ObjectOutput, Externalizable}
-import java.nio.ByteBuffer
+import org.apache.spark.streaming.StreamingContext
+import org.apache.spark.util.Utils
+import org.apache.spark.storage.StorageLevel
 
 private[streaming]
 class FlumeInputDStream[T: ClassManifest](
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ForEachDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ForEachDStream.scala
index c1f95650c8..e21bac4602 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ForEachDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ForEachDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.{Duration, DStream, Job, Time}
 
 private[streaming]
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/GlommedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/GlommedDStream.scala
index 1e4c7e7fde..4294b07d91 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/GlommedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/GlommedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 private[streaming]
 class GlommedDStream[T: ClassManifest](parent: DStream[T])
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapPartitionedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapPartitionedDStream.scala
index 1d79d707bb..5329601a6f 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapPartitionedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapPartitionedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 private[streaming]
 class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapValuedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapValuedDStream.scala
index 312e0c0567..8290df90a2 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapValuedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MapValuedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 
 private[streaming]
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MappedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MappedDStream.scala
index af688dde5f..b1682afea3 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/MappedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/MappedDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 
 private[streaming]
 class MappedDStream[T: ClassManifest, U: ClassManifest] (
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/NetworkInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/NetworkInputDStream.scala
index 3d68da36a2..31f9891560 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/NetworkInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/NetworkInputDStream.scala
@@ -17,22 +17,21 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.streaming.{Time, StreamingContext, AddBlocks, RegisterReceiver, DeregisterReceiver}
-
-import org.apache.spark.{Logging, SparkEnv, RDD}
-import org.apache.spark.rdd.BlockRDD
-import org.apache.spark.storage.StorageLevel
+import java.util.concurrent.ArrayBlockingQueue
+import java.nio.ByteBuffer
 
 import scala.collection.mutable.ArrayBuffer
 
-import java.nio.ByteBuffer
-
 import akka.actor.{Props, Actor}
 import akka.pattern.ask
 import akka.dispatch.Await
 import akka.util.duration._
+
 import org.apache.spark.streaming.util.{RecurringTimer, SystemClock}
-import java.util.concurrent.ArrayBlockingQueue
+import org.apache.spark.streaming._
+import org.apache.spark.{Logging, SparkEnv}
+import org.apache.spark.rdd.{RDD, BlockRDD}
+import org.apache.spark.storage.StorageLevel
 
 /**
  * Abstract class for defining any InputDStream that has to start a receiver on worker
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/QueueInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/QueueInputDStream.scala
index b43ecaeebe..7d9f3521b1 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/QueueInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/QueueInputDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.UnionRDD
 
 import scala.collection.mutable.Queue
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReducedWindowedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReducedWindowedDStream.scala
index b6c672f899..b88a4db959 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReducedWindowedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReducedWindowedDStream.scala
@@ -19,7 +19,7 @@ package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.StreamingContext._
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.{CoGroupedRDD, MapPartitionsRDD}
 import org.apache.spark.Partitioner
 import org.apache.spark.SparkContext._
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ShuffledDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ShuffledDStream.scala
index 3a0bd2acd7..a95e66d761 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ShuffledDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ShuffledDStream.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.{RDD, Partitioner}
+import org.apache.spark.Partitioner
+import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
 import org.apache.spark.streaming.{Duration, DStream, Time}
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/StateDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/StateDStream.scala
index c1c9f808f0..362a6bf4cc 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/StateDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/StateDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.Partitioner
 import org.apache.spark.SparkContext._
 import org.apache.spark.storage.StorageLevel
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
index edba2032b4..60485adef9 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.{Duration, DStream, Time}
 
 private[streaming]
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/UnionDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/UnionDStream.scala
index 97eab97b2f..c696bb70a8 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/UnionDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/UnionDStream.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.dstream
 
 import org.apache.spark.streaming.{Duration, DStream, Time}
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import collection.mutable.ArrayBuffer
 import org.apache.spark.rdd.UnionRDD
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/WindowedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/WindowedDStream.scala
index dbbea39e81..3c57294269 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/WindowedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/WindowedDStream.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.streaming.dstream
 
-import org.apache.spark.RDD
+import org.apache.spark.rdd.RDD
 import org.apache.spark.rdd.UnionRDD
 import org.apache.spark.storage.StorageLevel
 import org.apache.spark.streaming.{Duration, Interval, Time, DStream}
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/util/MasterFailureTest.scala b/streaming/src/main/scala/org/apache/spark/streaming/util/MasterFailureTest.scala
index 50d72298e4..6977957126 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/util/MasterFailureTest.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/util/MasterFailureTest.scala
@@ -17,7 +17,8 @@
 
 package org.apache.spark.streaming.util
 
-import org.apache.spark.{Logging, RDD}
+import org.apache.spark.Logging
+import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming._
 import org.apache.spark.streaming.dstream.ForEachDStream
 import StreamingContext._
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/util/RawTextSender.scala b/streaming/src/main/scala/org/apache/spark/streaming/util/RawTextSender.scala
index 249f6a22ae..fc8655a083 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/util/RawTextSender.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/util/RawTextSender.scala
@@ -20,10 +20,11 @@ package org.apache.spark.streaming.util
 import java.nio.ByteBuffer
 import org.apache.spark.util.{RateLimitedOutputStream, IntParam}
 import java.net.ServerSocket
-import org.apache.spark.{Logging, KryoSerializer}
+import org.apache.spark.{Logging}
 import it.unimi.dsi.fastutil.io.FastByteArrayOutputStream
 import scala.io.Source
 import java.io.IOException
+import org.apache.spark.serializer.KryoSerializer
 
 /**
  * A helper program that sends blocks of Kryo-serialized text strings out on a socket at a
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/TestSuiteBase.scala b/streaming/src/test/scala/org/apache/spark/streaming/TestSuiteBase.scala
index 31c2fa0208..37dd9c4cc6 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/TestSuiteBase.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/TestSuiteBase.scala
@@ -20,8 +20,6 @@ package org.apache.spark.streaming
 import org.apache.spark.streaming.dstream.{InputDStream, ForEachDStream}
 import org.apache.spark.streaming.util.ManualClock
 
-import org.apache.spark.{RDD, Logging}
-
 import collection.mutable.ArrayBuffer
 import collection.mutable.SynchronizedBuffer
 
@@ -29,6 +27,9 @@ import java.io.{ObjectInputStream, IOException}
 
 import org.scalatest.{BeforeAndAfter, FunSuite}
 
+import org.apache.spark.Logging
+import org.apache.spark.rdd.RDD
+
 /**
  * This is a input stream just for the testsuites. This is equivalent to a checkpointable,
  * replayable, reliable message queue like Kafka. It requires a sequence as input, and
diff --git a/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala b/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
index 50335e5736..f824c472ae 100644
--- a/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
+++ b/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
@@ -23,7 +23,7 @@ import scala.collection.mutable.ArrayBuffer
 
 import org.apache.spark._
 import org.apache.spark.api.java._
-import org.apache.spark.rdd.OrderedRDDFunctions
+import org.apache.spark.rdd.{RDD, DoubleRDDFunctions, PairRDDFunctions, OrderedRDDFunctions}
 import org.apache.spark.streaming.{PairDStreamFunctions, DStream, StreamingContext}
 import org.apache.spark.streaming.api.java.{JavaPairDStream, JavaDStream, JavaStreamingContext}
 
@@ -139,7 +139,7 @@ object JavaAPICompletenessChecker {
       scalaType match {
         case ParameterizedType(name, parameters, typebounds) =>
           name match {
-            case "org.apache.spark.RDD" =>
+            case "org.apache.spark.rdd.RDD" =>
               if (parameters(0).name == classOf[Tuple2[_, _]].getName) {
                 val tupleParams =
                   parameters(0).asInstanceOf[ParameterizedType].parameters.map(applySubs)
@@ -211,23 +211,23 @@ object JavaAPICompletenessChecker {
     // This list also includes a few methods that are only used by the web UI or other
     // internal Spark components.
     val excludedNames = Seq(
-      "org.apache.spark.RDD.origin",
-      "org.apache.spark.RDD.elementClassManifest",
-      "org.apache.spark.RDD.checkpointData",
-      "org.apache.spark.RDD.partitioner",
-      "org.apache.spark.RDD.partitions",
-      "org.apache.spark.RDD.firstParent",
-      "org.apache.spark.RDD.doCheckpoint",
-      "org.apache.spark.RDD.markCheckpointed",
-      "org.apache.spark.RDD.clearDependencies",
-      "org.apache.spark.RDD.getDependencies",
-      "org.apache.spark.RDD.getPartitions",
-      "org.apache.spark.RDD.dependencies",
-      "org.apache.spark.RDD.getPreferredLocations",
-      "org.apache.spark.RDD.collectPartitions",
-      "org.apache.spark.RDD.computeOrReadCheckpoint",
-      "org.apache.spark.PairRDDFunctions.getKeyClass",
-      "org.apache.spark.PairRDDFunctions.getValueClass",
+      "org.apache.spark.rdd.RDD.origin",
+      "org.apache.spark.rdd.RDD.elementClassManifest",
+      "org.apache.spark.rdd.RDD.checkpointData",
+      "org.apache.spark.rdd.RDD.partitioner",
+      "org.apache.spark.rdd.RDD.partitions",
+      "org.apache.spark.rdd.RDD.firstParent",
+      "org.apache.spark.rdd.RDD.doCheckpoint",
+      "org.apache.spark.rdd.RDD.markCheckpointed",
+      "org.apache.spark.rdd.RDD.clearDependencies",
+      "org.apache.spark.rdd.RDD.getDependencies",
+      "org.apache.spark.rdd.RDD.getPartitions",
+      "org.apache.spark.rdd.RDD.dependencies",
+      "org.apache.spark.rdd.RDD.getPreferredLocations",
+      "org.apache.spark.rdd.RDD.collectPartitions",
+      "org.apache.spark.rdd.RDD.computeOrReadCheckpoint",
+      "org.apache.spark.rdd.PairRDDFunctions.getKeyClass",
+      "org.apache.spark.rdd.PairRDDFunctions.getValueClass",
       "org.apache.spark.SparkContext.stringToText",
       "org.apache.spark.SparkContext.makeRDD",
       "org.apache.spark.SparkContext.runJob",