Merge branch 'dev' of github.com:mesos/spark into dev

25 files changed, 228 insertions, 99 deletions

diff --git a/core/src/main/scala/spark/RDD.scala b/core/src/main/scala/spark/RDD.scala
index 3244753bfe..f0d2b2d783 100644
--- a/core/src/main/scala/spark/RDD.scala
+++ b/core/src/main/scala/spark/RDD.scala
@@ -31,6 +31,17 @@ import spark.partial.BoundedDouble
 import spark.partial.CountEvaluator
 import spark.partial.GroupedCountEvaluator
 import spark.partial.PartialResult
+import spark.rdd.BlockRDD
+import spark.rdd.CartesianRDD
+import spark.rdd.FilteredRDD
+import spark.rdd.FlatMappedRDD
+import spark.rdd.GlommedRDD
+import spark.rdd.MappedRDD
+import spark.rdd.MapPartitionsRDD
+import spark.rdd.MapPartitionsWithSplitRDD
+import spark.rdd.PipedRDD
+import spark.rdd.SampledRDD
+import spark.rdd.UnionRDD
 import spark.storage.StorageLevel
 
 import SparkContext._
@@ -413,67 +424,4 @@ abstract class RDD[T: ClassManifest](@transient sc: SparkContext) extends Serial
   private[spark] def collectPartitions(): Array[Array[T]] = {
     sc.runJob(this, (iter: Iterator[T]) => iter.toArray)
   }
-}
-
-private[spark]
-class MappedRDD[U: ClassManifest, T: ClassManifest](
-    prev: RDD[T],
-    f: T => U)
-  extends RDD[U](prev.context) {
-  
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = prev.iterator(split).map(f)
-}
-
-private[spark]
-class FlatMappedRDD[U: ClassManifest, T: ClassManifest](
-    prev: RDD[T],
-    f: T => TraversableOnce[U])
-  extends RDD[U](prev.context) {
-  
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = prev.iterator(split).flatMap(f)
-}
-
-private[spark]
-class FilteredRDD[T: ClassManifest](prev: RDD[T], f: T => Boolean) extends RDD[T](prev.context) {
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = prev.iterator(split).filter(f)
-}
-
-private[spark]
-class GlommedRDD[T: ClassManifest](prev: RDD[T]) extends RDD[Array[T]](prev.context) {
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = Array(prev.iterator(split).toArray).iterator
-}
-
-private[spark]
-class MapPartitionsRDD[U: ClassManifest, T: ClassManifest](
-    prev: RDD[T],
-    f: Iterator[T] => Iterator[U])
-  extends RDD[U](prev.context) {
-  
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = f(prev.iterator(split))
-}
-
-/**
- * A variant of the MapPartitionsRDD that passes the split index into the
- * closure. This can be used to generate or collect partition specific
- * information such as the number of tuples in a partition.
- */
-private[spark]
-class MapPartitionsWithSplitRDD[U: ClassManifest, T: ClassManifest](
-    prev: RDD[T],
-    f: (Int, Iterator[T]) => Iterator[U])
-  extends RDD[U](prev.context) {
-
-  override def splits = prev.splits
-  override val dependencies = List(new OneToOneDependency(prev))
-  override def compute(split: Split) = f(split.index, prev.iterator(split))
-}
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/SparkContext.scala b/core/src/main/scala/spark/SparkContext.scala
index 37ba308546..84fc541f82 100644
--- a/core/src/main/scala/spark/SparkContext.scala
+++ b/core/src/main/scala/spark/SparkContext.scala
@@ -4,12 +4,11 @@ import java.io._
 import java.util.concurrent.atomic.AtomicInteger
 import java.net.{URI, URLClassLoader}
 
-import akka.actor.Actor
-import akka.actor.Actor._
-
 import scala.collection.mutable.{ArrayBuffer, HashMap}
 import scala.collection.generic.Growable
 
+import akka.actor.Actor
+import akka.actor.Actor._
 import org.apache.hadoop.fs.{FileUtil, Path}
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.mapred.InputFormat
@@ -27,20 +26,22 @@ import org.apache.hadoop.io.Text
 import org.apache.hadoop.mapred.FileInputFormat
 import org.apache.hadoop.mapred.JobConf
 import org.apache.hadoop.mapred.TextInputFormat
-
 import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
 import org.apache.hadoop.mapreduce.lib.input.{FileInputFormat => NewFileInputFormat}
 import org.apache.hadoop.mapreduce.{Job => NewHadoopJob}
-
 import org.apache.mesos.{Scheduler, MesosNativeLibrary}
 
 import spark.broadcast._
-
 import spark.deploy.LocalSparkCluster
-
 import spark.partial.ApproximateEvaluator
 import spark.partial.PartialResult
-
+import spark.rdd.DoubleRDDFunctions
+import spark.rdd.HadoopRDD
+import spark.rdd.NewHadoopRDD
+import spark.rdd.OrderedRDDFunctions
+import spark.rdd.PairRDDFunctions
+import spark.rdd.SequenceFileRDDFunctions
+import spark.rdd.UnionRDD
 import spark.scheduler.ShuffleMapTask
 import spark.scheduler.DAGScheduler
 import spark.scheduler.TaskScheduler
diff --git a/core/src/main/scala/spark/api/java/JavaPairRDD.scala b/core/src/main/scala/spark/api/java/JavaPairRDD.scala
index 84ec386ce4..3c4399493c 100644
--- a/core/src/main/scala/spark/api/java/JavaPairRDD.scala
+++ b/core/src/main/scala/spark/api/java/JavaPairRDD.scala
@@ -1,13 +1,5 @@
 package spark.api.java
 
-import spark.SparkContext.rddToPairRDDFunctions
-import spark.api.java.function.{Function2 => JFunction2}
-import spark.api.java.function.{Function => JFunction}
-import spark.partial.BoundedDouble
-import spark.partial.PartialResult
-import spark.storage.StorageLevel
-import spark._
-
 import java.util.{List => JList}
 import java.util.Comparator
 
@@ -19,6 +11,17 @@ import org.apache.hadoop.mapred.OutputFormat
 import org.apache.hadoop.mapreduce.{OutputFormat => NewOutputFormat}
 import org.apache.hadoop.conf.Configuration
 
+import spark.api.java.function.{Function2 => JFunction2}
+import spark.api.java.function.{Function => JFunction}
+import spark.partial.BoundedDouble
+import spark.partial.PartialResult
+import spark.rdd.OrderedRDDFunctions
+import spark.storage.StorageLevel
+import spark.HashPartitioner
+import spark.Partitioner
+import spark.RDD
+import spark.SparkContext.rddToPairRDDFunctions
+
 class JavaPairRDD[K, V](val rdd: RDD[(K, V)])(implicit val kManifest: ClassManifest[K],
   implicit val vManifest: ClassManifest[V]) extends JavaRDDLike[(K, V), JavaPairRDD[K, V]] {
 
diff --git a/core/src/main/scala/spark/BlockRDD.scala b/core/src/main/scala/spark/rdd/BlockRDD.scala
index afc732234f..cb73976aed 100644
--- a/core/src/main/scala/spark/BlockRDD.scala
+++ b/core/src/main/scala/spark/rdd/BlockRDD.scala
@@ -1,7 +1,13 @@
-package spark
+package spark.rdd
 
 import scala.collection.mutable.HashMap
 
+import spark.Dependency
+import spark.RDD
+import spark.SparkContext
+import spark.SparkEnv
+import spark.Split
+
 private[spark] class BlockRDDSplit(val blockId: String, idx: Int) extends Split {
   val index = idx
 }
diff --git a/core/src/main/scala/spark/CartesianRDD.scala b/core/src/main/scala/spark/rdd/CartesianRDD.scala
index 52aab5f32f..7c354b6b2e 100644
--- a/core/src/main/scala/spark/CartesianRDD.scala
+++ b/core/src/main/scala/spark/rdd/CartesianRDD.scala
@@ -1,4 +1,9 @@
-package spark
+package spark.rdd
+
+import spark.NarrowDependency
+import spark.RDD
+import spark.SparkContext
+import spark.Split
 
 private[spark]
 class CartesianSplit(idx: Int, val s1: Split, val s2: Split) extends Split with Serializable {
diff --git a/core/src/main/scala/spark/CoGroupedRDD.scala b/core/src/main/scala/spark/rdd/CoGroupedRDD.scala
index daba719b14..8fa0749184 100644
--- a/core/src/main/scala/spark/CoGroupedRDD.scala
+++ b/core/src/main/scala/spark/rdd/CoGroupedRDD.scala
@@ -1,11 +1,22 @@
-package spark
+package spark.rdd
 
 import java.net.URL
 import java.io.EOFException
 import java.io.ObjectInputStream
+
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashMap
 
+import spark.Aggregator
+import spark.Dependency
+import spark.Logging
+import spark.OneToOneDependency
+import spark.Partitioner
+import spark.RDD
+import spark.ShuffleDependency
+import spark.SparkEnv
+import spark.Split
+
 private[spark] sealed trait CoGroupSplitDep extends Serializable
 private[spark] case class NarrowCoGroupSplitDep(rdd: RDD[_], split: Split) extends CoGroupSplitDep
 private[spark] case class ShuffleCoGroupSplitDep(shuffleId: Int) extends CoGroupSplitDep
diff --git a/core/src/main/scala/spark/CoalescedRDD.scala b/core/src/main/scala/spark/rdd/CoalescedRDD.scala
index f1ae346a44..0967f4f5df 100644
--- a/core/src/main/scala/spark/CoalescedRDD.scala
+++ b/core/src/main/scala/spark/rdd/CoalescedRDD.scala
@@ -1,4 +1,8 @@
-package spark
+package spark.rdd
+
+import spark.NarrowDependency
+import spark.RDD
+import spark.Split
 
 private class CoalescedRDDSplit(val index: Int, val parents: Array[Split]) extends Split
 
diff --git a/core/src/main/scala/spark/DoubleRDDFunctions.scala b/core/src/main/scala/spark/rdd/DoubleRDDFunctions.scala
index 1fbf66b7de..d232ddeb7c 100644
--- a/core/src/main/scala/spark/DoubleRDDFunctions.scala
+++ b/core/src/main/scala/spark/rdd/DoubleRDDFunctions.scala
@@ -1,10 +1,13 @@
-package spark
+package spark.rdd
 
 import spark.partial.BoundedDouble
 import spark.partial.MeanEvaluator
 import spark.partial.PartialResult
 import spark.partial.SumEvaluator
 
+import spark.Logging
+import spark.RDD
+import spark.TaskContext
 import spark.util.StatCounter
 
 /**
diff --git a/core/src/main/scala/spark/rdd/FilteredRDD.scala b/core/src/main/scala/spark/rdd/FilteredRDD.scala
new file mode 100644
index 0000000000..dfe9dc73f3
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/FilteredRDD.scala
@@ -0,0 +1,12 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+private[spark]
+class FilteredRDD[T: ClassManifest](prev: RDD[T], f: T => Boolean) extends RDD[T](prev.context) {
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = prev.iterator(split).filter(f)
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/rdd/FlatMappedRDD.scala b/core/src/main/scala/spark/rdd/FlatMappedRDD.scala
new file mode 100644
index 0000000000..3534dc8057
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/FlatMappedRDD.scala
@@ -0,0 +1,16 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+private[spark]
+class FlatMappedRDD[U: ClassManifest, T: ClassManifest](
+    prev: RDD[T],
+    f: T => TraversableOnce[U])
+  extends RDD[U](prev.context) {
+  
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = prev.iterator(split).flatMap(f)
+}
diff --git a/core/src/main/scala/spark/rdd/GlommedRDD.scala b/core/src/main/scala/spark/rdd/GlommedRDD.scala
new file mode 100644
index 0000000000..e30564f2da
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/GlommedRDD.scala
@@ -0,0 +1,12 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+private[spark]
+class GlommedRDD[T: ClassManifest](prev: RDD[T]) extends RDD[Array[T]](prev.context) {
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = Array(prev.iterator(split).toArray).iterator
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/HadoopRDD.scala b/core/src/main/scala/spark/rdd/HadoopRDD.scala
index 6d448116a9..bf29a1f075 100644
--- a/core/src/main/scala/spark/HadoopRDD.scala
+++ b/core/src/main/scala/spark/rdd/HadoopRDD.scala
@@ -1,4 +1,4 @@
-package spark
+package spark.rdd
 
 import java.io.EOFException
 import java.util.NoSuchElementException
@@ -15,6 +15,12 @@ import org.apache.hadoop.mapred.RecordReader
 import org.apache.hadoop.mapred.Reporter
 import org.apache.hadoop.util.ReflectionUtils
 
+import spark.Dependency
+import spark.RDD
+import spark.SerializableWritable
+import spark.SparkContext
+import spark.Split
+
 /** 
  * A Spark split class that wraps around a Hadoop InputSplit.
  */
diff --git a/core/src/main/scala/spark/rdd/MapPartitionsRDD.scala b/core/src/main/scala/spark/rdd/MapPartitionsRDD.scala
new file mode 100644
index 0000000000..b2c7a1cb9e
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/MapPartitionsRDD.scala
@@ -0,0 +1,16 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+private[spark]
+class MapPartitionsRDD[U: ClassManifest, T: ClassManifest](
+    prev: RDD[T],
+    f: Iterator[T] => Iterator[U])
+  extends RDD[U](prev.context) {
+  
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = f(prev.iterator(split))
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/rdd/MapPartitionsWithSplitRDD.scala b/core/src/main/scala/spark/rdd/MapPartitionsWithSplitRDD.scala
new file mode 100644
index 0000000000..adc541694e
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/MapPartitionsWithSplitRDD.scala
@@ -0,0 +1,21 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+/**
+ * A variant of the MapPartitionsRDD that passes the split index into the
+ * closure. This can be used to generate or collect partition specific
+ * information such as the number of tuples in a partition.
+ */
+private[spark]
+class MapPartitionsWithSplitRDD[U: ClassManifest, T: ClassManifest](
+    prev: RDD[T],
+    f: (Int, Iterator[T]) => Iterator[U])
+  extends RDD[U](prev.context) {
+
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = f(split.index, prev.iterator(split))
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/rdd/MappedRDD.scala b/core/src/main/scala/spark/rdd/MappedRDD.scala
new file mode 100644
index 0000000000..59bedad8ef
--- /dev/null
+++ b/core/src/main/scala/spark/rdd/MappedRDD.scala
@@ -0,0 +1,16 @@
+package spark.rdd
+
+import spark.OneToOneDependency
+import spark.RDD
+import spark.Split
+
+private[spark]
+class MappedRDD[U: ClassManifest, T: ClassManifest](
+    prev: RDD[T],
+    f: T => U)
+  extends RDD[U](prev.context) {
+  
+  override def splits = prev.splits
+  override val dependencies = List(new OneToOneDependency(prev))
+  override def compute(split: Split) = prev.iterator(split).map(f)
+}
\ No newline at end of file
diff --git a/core/src/main/scala/spark/NewHadoopRDD.scala b/core/src/main/scala/spark/rdd/NewHadoopRDD.scala
index 9072698357..dcbceab246 100644
--- a/core/src/main/scala/spark/NewHadoopRDD.scala
+++ b/core/src/main/scala/spark/rdd/NewHadoopRDD.scala
@@ -1,4 +1,4 @@
-package spark
+package spark.rdd
 
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.io.Writable
@@ -13,6 +13,12 @@ import org.apache.hadoop.mapreduce.TaskAttemptID
 import java.util.Date
 import java.text.SimpleDateFormat
 
+import spark.Dependency
+import spark.RDD
+import spark.SerializableWritable
+import spark.SparkContext
+import spark.Split
+
 private[spark] 
 class NewHadoopSplit(rddId: Int, val index: Int, @transient rawSplit: InputSplit with Writable)
   extends Split {
diff --git a/core/src/main/scala/spark/PairRDDFunctions.scala b/core/src/main/scala/spark/rdd/PairRDDFunctions.scala
index 80d62caf25..2a94ea263a 100644
--- a/core/src/main/scala/spark/PairRDDFunctions.scala
+++ b/core/src/main/scala/spark/rdd/PairRDDFunctions.scala
@@ -1,4 +1,4 @@
-package spark
+package spark.rdd
 
 import java.io.EOFException
 import java.io.ObjectInputStream
@@ -34,9 +34,20 @@ import org.apache.hadoop.mapreduce.{Job => NewAPIHadoopJob}
 import org.apache.hadoop.mapreduce.TaskAttemptID
 import org.apache.hadoop.mapreduce.TaskAttemptContext
 
-import spark.SparkContext._
 import spark.partial.BoundedDouble
 import spark.partial.PartialResult
+import spark.Aggregator
+import spark.HashPartitioner
+import spark.Logging
+import spark.OneToOneDependency
+import spark.Partitioner
+import spark.RangePartitioner
+import spark.RDD
+import spark.SerializableWritable
+import spark.SparkContext._
+import spark.SparkException
+import spark.Split
+import spark.TaskContext
 
 /**
  * Extra functions available on RDDs of (key, value) pairs through an implicit conversion.
diff --git a/core/src/main/scala/spark/PipedRDD.scala b/core/src/main/scala/spark/rdd/PipedRDD.scala
index 3103d7889b..98ea0c92d6 100644
--- a/core/src/main/scala/spark/PipedRDD.scala
+++ b/core/src/main/scala/spark/rdd/PipedRDD.scala
@@ -1,4 +1,4 @@
-package spark
+package spark.rdd
 
 import java.io.PrintWriter
 import java.util.StringTokenizer
@@ -8,6 +8,12 @@ import scala.collection.JavaConversions._
 import scala.collection.mutable.ArrayBuffer
 import scala.io.Source
 
+import spark.OneToOneDependency
+import spark.RDD
+import spark.SparkEnv
+import spark.Split
+
+
 /**
  * An RDD that pipes the contents of each parent partition through an external command
  * (printing them one per line) and returns the output as a collection of strings.
diff --git a/core/src/main/scala/spark/SampledRDD.scala b/core/src/main/scala/spark/rdd/SampledRDD.scala
index ac10aed477..87a5268f27 100644
--- a/core/src/main/scala/spark/SampledRDD.scala
+++ b/core/src/main/scala/spark/rdd/SampledRDD.scala
@@ -1,9 +1,13 @@
-package spark
+package spark.rdd
 
 import java.util.Random
 import cern.jet.random.Poisson
 import cern.jet.random.engine.DRand
 
+import spark.RDD
+import spark.OneToOneDependency
+import spark.Split
+
 private[spark]
 class SampledRDDSplit(val prev: Split, val seed: Int) extends Split with Serializable {
   override val index: Int = prev.index
diff --git a/core/src/main/scala/spark/SequenceFileRDDFunctions.scala b/core/src/main/scala/spark/rdd/SequenceFileRDDFunctions.scala
index ea7171d3a1..24c731fa92 100644
--- a/core/src/main/scala/spark/SequenceFileRDDFunctions.scala
+++ b/core/src/main/scala/spark/rdd/SequenceFileRDDFunctions.scala
@@ -1,4 +1,4 @@
-package spark
+package spark.rdd
 
 import java.io.EOFException
 import java.net.URL
@@ -23,7 +23,9 @@ import org.apache.hadoop.io.NullWritable
 import org.apache.hadoop.io.BytesWritable
 import org.apache.hadoop.io.Text
 
-import SparkContext._
+import spark.Logging
+import spark.RDD
+import spark.SparkContext._
 
 /**
  * Extra functions available on RDDs of (key, value) pairs to create a Hadoop SequenceFile,
diff --git a/core/src/main/scala/spark/ShuffledRDD.scala b/core/src/main/scala/spark/rdd/ShuffledRDD.scala
index 1a9f4cfec3..769ccf8caa 100644
--- a/core/src/main/scala/spark/ShuffledRDD.scala
+++ b/core/src/main/scala/spark/rdd/ShuffledRDD.scala
@@ -1,8 +1,15 @@
-package spark
+package spark.rdd
 
 import scala.collection.mutable.ArrayBuffer
 import java.util.{HashMap => JHashMap}
 
+import spark.Aggregator
+import spark.Partitioner
+import spark.RangePartitioner
+import spark.RDD
+import spark.ShuffleDependency
+import spark.SparkEnv
+import spark.Split
 
 private[spark] class ShuffledRDDSplit(val idx: Int) extends Split {
   override val index = idx
diff --git a/core/src/main/scala/spark/UnionRDD.scala b/core/src/main/scala/spark/rdd/UnionRDD.scala
index 3e795ea2a2..4ba2848491 100644
--- a/core/src/main/scala/spark/UnionRDD.scala
+++ b/core/src/main/scala/spark/rdd/UnionRDD.scala
@@ -1,7 +1,13 @@
-package spark
+package spark.rdd
 
 import scala.collection.mutable.ArrayBuffer
 
+import spark.Dependency
+import spark.RangeDependency
+import spark.RDD
+import spark.SparkContext
+import spark.Split
+
 private[spark] class UnionSplit[T: ClassManifest](
     idx: Int, 
     rdd: RDD[T],
diff --git a/core/src/test/scala/spark/AccumulatorSuite.scala b/core/src/test/scala/spark/AccumulatorSuite.scala
index b920e53534..403e675f37 100644
--- a/core/src/test/scala/spark/AccumulatorSuite.scala
+++ b/core/src/test/scala/spark/AccumulatorSuite.scala
@@ -18,6 +18,7 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers with BeforeAndAfter
       sc.stop()
       sc = null
     }
+    System.clearProperty("spark.master.port")
   }
 
   test ("basic accumulation"){
@@ -91,7 +92,7 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers with BeforeAndAfter
     val maxI = 1000
     for (nThreads <- List(1, 10)) {
       // test single & multi-threaded
-      val sc = new SparkContext("local[" + nThreads + "]", "test")
+      sc = new SparkContext("local[" + nThreads + "]", "test")
       val setAcc = sc.accumulableCollection(mutable.HashSet[Int]())
       val bufferAcc = sc.accumulableCollection(mutable.ArrayBuffer[Int]())
       val mapAcc = sc.accumulableCollection(mutable.HashMap[Int,String]())
@@ -110,6 +111,7 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers with BeforeAndAfter
         mapAcc.value should contain (i -> i.toString)
       }
       sc.stop()
+      sc = null      
     }
   }
 
@@ -117,7 +119,7 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers with BeforeAndAfter
     import SetAccum._
     val maxI = 1000
     for (nThreads <- List(1, 10)) { //test single & multi-threaded
-    val sc = new SparkContext("local[" + nThreads + "]", "test")
+	  sc = new SparkContext("local[" + nThreads + "]", "test")
       val acc: Accumulable[mutable.Set[Any], Any] = sc.accumulable(new mutable.HashSet[Any]())
       val groupedInts = (1 to (maxI/20)).map {x => (20 * (x - 1) to 20 * x).toSet}
       val d = sc.parallelize(groupedInts)
@@ -125,6 +127,8 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers with BeforeAndAfter
         x => acc.localValue ++= x
       }
       acc.value should be ( (0 to maxI).toSet)
+      sc.stop()
+      sc = null      
     }
   }
 
diff --git a/core/src/test/scala/spark/RDDSuite.scala b/core/src/test/scala/spark/RDDSuite.scala
index ade457c0f9..95e402627c 100644
--- a/core/src/test/scala/spark/RDDSuite.scala
+++ b/core/src/test/scala/spark/RDDSuite.scala
@@ -3,6 +3,8 @@ package spark
 import scala.collection.mutable.HashMap
 import org.scalatest.FunSuite
 import org.scalatest.BeforeAndAfter
+
+import spark.rdd.CoalescedRDD
 import SparkContext._
 
 class RDDSuite extends FunSuite with BeforeAndAfter {
diff --git a/core/src/test/scala/spark/ShuffleSuite.scala b/core/src/test/scala/spark/ShuffleSuite.scala
index 90760b8a85..068607824b 100644
--- a/core/src/test/scala/spark/ShuffleSuite.scala
+++ b/core/src/test/scala/spark/ShuffleSuite.scala
@@ -1,5 +1,7 @@
 package spark
 
+import scala.collection.mutable.ArrayBuffer
+
 import org.scalatest.FunSuite
 import org.scalatest.BeforeAndAfter
 import org.scalatest.matchers.ShouldMatchers
@@ -10,8 +12,7 @@ import org.scalacheck.Prop._
 
 import com.google.common.io.Files
 
-import scala.collection.mutable.ArrayBuffer
-
+import spark.rdd.ShuffledAggregatedRDD
 import SparkContext._
 
 class ShuffleSuite extends FunSuite with ShouldMatchers with BeforeAndAfter {