From 9e644402c155b5fc68794a17c36ddd19d3242f4f Mon Sep 17 00:00:00 2001
From: Tathagata Das <tathagata.das1565@gmail.com>
Date: Sat, 29 Dec 2012 18:31:51 -0800
Subject: Improved jekyll and scala docs. Made many classes and method private
 to remove them from scala docs.

---
 .../main/scala/spark/streaming/Checkpoint.scala    |   5 +-
 .../src/main/scala/spark/streaming/DStream.scala   | 249 +++++++++++++--------
 .../scala/spark/streaming/FlumeInputDStream.scala  |   2 +-
 .../src/main/scala/spark/streaming/Interval.scala  |   1 +
 streaming/src/main/scala/spark/streaming/Job.scala |   2 +
 .../main/scala/spark/streaming/JobManager.scala    |   1 +
 .../spark/streaming/NetworkInputDStream.scala      |   8 +-
 .../spark/streaming/NetworkInputTracker.scala      |   8 +-
 .../spark/streaming/PairDStreamFunctions.scala     |   4 +-
 .../src/main/scala/spark/streaming/Scheduler.scala |   7 +-
 .../scala/spark/streaming/StreamingContext.scala   |  43 ++--
 .../scala/spark/streaming/examples/GrepRaw.scala   |   2 +-
 .../streaming/examples/TopKWordCountRaw.scala      |   2 +-
 .../spark/streaming/examples/WordCountRaw.scala    |   2 +-
 .../examples/clickstream/PageViewStream.scala      |   2 +-
 .../test/scala/spark/streaming/TestSuiteBase.scala |   2 +-
 16 files changed, 201 insertions(+), 139 deletions(-)

(limited to 'streaming')

diff --git a/streaming/src/main/scala/spark/streaming/Checkpoint.scala b/streaming/src/main/scala/spark/streaming/Checkpoint.scala
index 770f7b0cc0..11a7232d7b 100644
--- a/streaming/src/main/scala/spark/streaming/Checkpoint.scala
+++ b/streaming/src/main/scala/spark/streaming/Checkpoint.scala
@@ -8,6 +8,7 @@ import org.apache.hadoop.conf.Configuration
 import java.io._
 
 
+private[streaming]
 class Checkpoint(@transient ssc: StreamingContext, val checkpointTime: Time)
   extends Logging with Serializable {
   val master = ssc.sc.master
@@ -30,6 +31,7 @@ class Checkpoint(@transient ssc: StreamingContext, val checkpointTime: Time)
 /**
  * Convenience class to speed up the writing of graph checkpoint to file
  */
+private[streaming]
 class CheckpointWriter(checkpointDir: String) extends Logging {
   val file = new Path(checkpointDir, "graph")
   val conf = new Configuration()
@@ -65,7 +67,7 @@ class CheckpointWriter(checkpointDir: String) extends Logging {
 }
 
 
-
+private[streaming]
 object CheckpointReader extends Logging {
 
   def read(path: String): Checkpoint = {
@@ -103,6 +105,7 @@ object CheckpointReader extends Logging {
   }
 }
 
+private[streaming]
 class ObjectInputStreamWithLoader(inputStream_ : InputStream, loader: ClassLoader) extends ObjectInputStream(inputStream_) {
   override def resolveClass(desc: ObjectStreamClass): Class[_] = {
     try {
diff --git a/streaming/src/main/scala/spark/streaming/DStream.scala b/streaming/src/main/scala/spark/streaming/DStream.scala
index d5048aeed7..3834b57ed3 100644
--- a/streaming/src/main/scala/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/spark/streaming/DStream.scala
@@ -21,7 +21,7 @@ import org.apache.hadoop.conf.Configuration
  * A Discretized Stream (DStream), the basic abstraction in Spark Streaming, is a continuous
  * sequence of RDDs (of the same type) representing a continuous stream of data (see [[spark.RDD]]
  * for more details on RDDs). DStreams can either be created from live data (such as, data from
- * HDFS. Kafka or Flume) or it can be generated by transformation existing DStreams using operations
+ * HDFS, Kafka or Flume) or it can be generated by transformation existing DStreams using operations
  * such as `map`, `window` and `reduceByKeyAndWindow`. While a Spark Streaming program is running, each
  * DStream periodically generates a RDD, either from live data or by transforming the RDD generated
  * by a parent DStream.
@@ -38,33 +38,28 @@ import org.apache.hadoop.conf.Configuration
  *  - A function that is used to generate an RDD after each time interval
  */
 
-case class DStreamCheckpointData(rdds: HashMap[Time, Any])
-
-abstract class DStream[T: ClassManifest] (@transient var ssc: StreamingContext)
-extends Serializable with Logging {
+abstract class DStream[T: ClassManifest] (
+    @transient protected[streaming] var ssc: StreamingContext
+  ) extends Serializable with Logging {
 
   initLogging()
 
-  /** 
-   * ----------------------------------------------
-   * Methods that must be implemented by subclasses
-   * ---------------------------------------------- 
-   */
+  // =======================================================================
+  // Methods that should be implemented by subclasses of DStream
+  // =======================================================================
 
-  // Time interval at which the DStream generates an RDD
+  /** Time interval after which the DStream generates a RDD */
   def slideTime: Time 
 
-  // List of parent DStreams on which this DStream depends on
+  /** List of parent DStreams on which this DStream depends on */
   def dependencies: List[DStream[_]]
 
-  // Key method that computes RDD for a valid time
+  /** Method that generates a RDD for the given time */
   def compute (validTime: Time): Option[RDD[T]]
 
-  /**
-   * --------------------------------------- 
-   * Other general fields and methods of DStream
-   * --------------------------------------- 
-   */
+  // =======================================================================
+  // Methods and fields available on all DStreams
+  // =======================================================================
 
   // RDDs generated, marked as protected[streaming] so that testsuites can access it
   @transient
@@ -87,12 +82,15 @@ extends Serializable with Logging {
   // Reference to whole DStream graph
   protected[streaming] var graph: DStreamGraph = null
 
-  def isInitialized = (zeroTime != null)
+  protected[streaming] def isInitialized = (zeroTime != null)
 
   // Duration for which the DStream requires its parent DStream to remember each RDD created
-  def parentRememberDuration = rememberDuration
+  protected[streaming] def parentRememberDuration = rememberDuration
+
+  /** Returns the StreamingContext associated with this DStream */
+  def context() = ssc
 
-  // Set caching level for the RDDs created by this DStream
+  /** Persists the RDDs of this DStream with the given storage level */
   def persist(level: StorageLevel): DStream[T] = {
     if (this.isInitialized) {
       throw new UnsupportedOperationException(
@@ -102,11 +100,16 @@ extends Serializable with Logging {
     this
   }
 
+  /** Persists RDDs of this DStream with the default storage level (MEMORY_ONLY_SER) */
   def persist(): DStream[T] = persist(StorageLevel.MEMORY_ONLY_SER)
-  
-  // Turn on the default caching level for this RDD
+
+  /** Persists RDDs of this DStream with the default storage level (MEMORY_ONLY_SER) */
   def cache(): DStream[T] = persist()
 
+  /**
+   * Enable periodic checkpointing of RDDs of this DStream
+   * @param interval Time interval after which generated RDD will be checkpointed
+   */
   def checkpoint(interval: Time): DStream[T] = {
     if (isInitialized) {
       throw new UnsupportedOperationException(
@@ -285,7 +288,7 @@ extends Serializable with Logging {
    * Generates a SparkStreaming job for the given time. This is an internal method that
    * should not be called directly. This default implementation creates a job
    * that materializes the corresponding RDD. Subclasses of DStream may override this
-   * (eg. PerRDDForEachDStream).
+   * (eg. ForEachDStream).
    */
   protected[streaming] def generateJob(time: Time): Option[Job] = {
     getOrCompute(time) match {
@@ -420,65 +423,96 @@ extends Serializable with Logging {
     generatedRDDs = new HashMap[Time, RDD[T]] ()
   }
 
-  /** 
-   * --------------
-   * DStream operations
-   * -------------- 
-   */
+  // =======================================================================
+  // DStream operations
+  // =======================================================================
+
+  /** Returns a new DStream by applying a function to all elements of this DStream. */
   def map[U: ClassManifest](mapFunc: T => U): DStream[U] = {
     new MappedDStream(this, ssc.sc.clean(mapFunc))
   }
 
+  /**
+   * Returns a new DStream by applying a function to all elements of this DStream,
+   * and then flattening the results
+   */
   def flatMap[U: ClassManifest](flatMapFunc: T => Traversable[U]): DStream[U] = {
     new FlatMappedDStream(this, ssc.sc.clean(flatMapFunc))
   }
 
+  /** Returns a new DStream containing only the elements that satisfy a predicate. */
   def filter(filterFunc: T => Boolean): DStream[T] = new FilteredDStream(this, filterFunc)
 
+  /**
+   * Return a new DStream in which each RDD is generated by applying glom() to each RDD of
+   * this DStream. Applying glom() to an RDD coalesces all elements within each partition into
+   * an array.
+   */
   def glom(): DStream[Array[T]] = new GlommedDStream(this)
 
-  def mapPartitions[U: ClassManifest](mapPartFunc: Iterator[T] => Iterator[U]): DStream[U] = {
-    new MapPartitionedDStream(this, ssc.sc.clean(mapPartFunc))
+  /**
+   * Return a new DStream in which each RDD is generated by applying mapPartitions() to each RDDs
+   * of this DStream. Applying mapPartitions() to an RDD applies a function to each partition
+   * of the RDD.
+   */
+  def mapPartitions[U: ClassManifest](
+      mapPartFunc: Iterator[T] => Iterator[U],
+      preservePartitioning: Boolean = false
+    ): DStream[U] = {
+    new MapPartitionedDStream(this, ssc.sc.clean(mapPartFunc), preservePartitioning)
   }
 
-  def reduce(reduceFunc: (T, T) => T): DStream[T] = this.map(x => (null, x)).reduceByKey(reduceFunc, 1).map(_._2)
+  /**
+   * Returns a new DStream in which each RDD has a single element generated by reducing each RDD
+   * of this DStream.
+   */
+  def reduce(reduceFunc: (T, T) => T): DStream[T] =
+    this.map(x => (null, x)).reduceByKey(reduceFunc, 1).map(_._2)
 
+  /**
+   * Returns a new DStream in which each RDD has a single element generated by counting each RDD
+   * of this DStream.
+   */
   def count(): DStream[Int] = this.map(_ => 1).reduce(_ + _)
-  
-  def collect(): DStream[Seq[T]] = this.map(x => (null, x)).groupByKey(1).map(_._2)
-
-  def foreach(foreachFunc: T => Unit) {
-    val newStream = new PerElementForEachDStream(this, ssc.sc.clean(foreachFunc))
-    ssc.registerOutputStream(newStream)
-    newStream
-  }
 
-  def foreachRDD(foreachFunc: RDD[T] => Unit) {
-    foreachRDD((r: RDD[T], t: Time) => foreachFunc(r))
+  /**
+   * Applies a function to each RDD in this DStream. This is an output operator, so
+   * this DStream will be registered as an output stream and therefore materialized.
+   */
+  def foreach(foreachFunc: RDD[T] => Unit) {
+    foreach((r: RDD[T], t: Time) => foreachFunc(r))
   }
 
-  def foreachRDD(foreachFunc: (RDD[T], Time) => Unit) {
-    val newStream = new PerRDDForEachDStream(this, ssc.sc.clean(foreachFunc))
+  /**
+   * Applies a function to each RDD in this DStream. This is an output operator, so
+   * this DStream will be registered as an output stream and therefore materialized.
+   */
+  def foreach(foreachFunc: (RDD[T], Time) => Unit) {
+    val newStream = new ForEachDStream(this, ssc.sc.clean(foreachFunc))
     ssc.registerOutputStream(newStream)
     newStream
   }
 
-  def transformRDD[U: ClassManifest](transformFunc: RDD[T] => RDD[U]): DStream[U] = {
-    transformRDD((r: RDD[T], t: Time) => transformFunc(r))
+  /**
+   * Returns a new DStream in which each RDD is generated by applying a function
+   * on each RDD of this DStream.
+   */
+  def transform[U: ClassManifest](transformFunc: RDD[T] => RDD[U]): DStream[U] = {
+    transform((r: RDD[T], t: Time) => transformFunc(r))
   }
 
-  def transformRDD[U: ClassManifest](transformFunc: (RDD[T], Time) => RDD[U]): DStream[U] = {
+  /**
+   * Returns a new DStream in which each RDD is generated by applying a function
+   * on each RDD of this DStream.
+   */
+  def transform[U: ClassManifest](transformFunc: (RDD[T], Time) => RDD[U]): DStream[U] = {
     new TransformedDStream(this, ssc.sc.clean(transformFunc))
   }
 
-  def toBlockingQueue() = {
-    val queue = new ArrayBlockingQueue[RDD[T]](10000)
-    this.foreachRDD(rdd => {
-      queue.add(rdd)
-    })
-    queue
-  }
-  
+  /**
+   * Prints the first ten elements of each RDD generated in this DStream. This is an output
+   * operator, so this DStream will be registered as an output stream and there materialized.
+   */
   def print() {
     def foreachFunc = (rdd: RDD[T], time: Time) => {
       val first11 = rdd.take(11)
@@ -489,18 +523,42 @@ extends Serializable with Logging {
       if (first11.size > 10) println("...")
       println()
     }
-    val newStream = new PerRDDForEachDStream(this, ssc.sc.clean(foreachFunc))
+    val newStream = new ForEachDStream(this, ssc.sc.clean(foreachFunc))
     ssc.registerOutputStream(newStream)
   }
 
+  /**
+   * Return a new DStream which is computed based on windowed batches of this DStream.
+   * The new DStream generates RDDs with the same interval as this DStream.
+   * @param windowTime width of the window; must be a multiple of this DStream's interval.
+   * @return
+   */
   def window(windowTime: Time): DStream[T] = window(windowTime, this.slideTime)
 
+  /**
+   * Return a new DStream which is computed based on windowed batches of this DStream.
+   * @param windowTime duration (i.e., width) of the window;
+   *                   must be a multiple of this DStream's interval
+   * @param slideTime  sliding interval of the window (i.e., the interval after which
+   *                   the new DStream will generate RDDs); must be a multiple of this
+   *                   DStream's interval
+   */
   def window(windowTime: Time, slideTime: Time): DStream[T] = {
     new WindowedDStream(this, windowTime, slideTime)
   }
 
+  /**
+   * Returns a new DStream which computed based on tumbling window on this DStream.
+   * This is equivalent to window(batchTime, batchTime).
+   * @param batchTime tumbling window duration; must be a multiple of this DStream's interval
+   */
   def tumble(batchTime: Time): DStream[T] = window(batchTime, batchTime)
 
+  /**
+   * Returns a new DStream in which each RDD has a single element generated by reducing all
+   * elements in a window over this DStream. windowTime and slideTime are as defined in the
+   * window() operation. This is equivalent to window(windowTime, slideTime).reduce(reduceFunc)
+   */
   def reduceByWindow(reduceFunc: (T, T) => T, windowTime: Time, slideTime: Time): DStream[T] = {
     this.window(windowTime, slideTime).reduce(reduceFunc)
   }
@@ -516,17 +574,31 @@ extends Serializable with Logging {
           .map(_._2)
   }
 
+  /**
+   * Returns a new DStream in which each RDD has a single element generated by counting the number
+   * of elements in a window over this DStream. windowTime and slideTime are as defined in the
+   * window() operation. This is equivalent to window(windowTime, slideTime).count()
+   */
   def countByWindow(windowTime: Time, slideTime: Time): DStream[Int] = {
     this.map(_ => 1).reduceByWindow(_ + _, _ - _, windowTime, slideTime)
   }
 
+  /**
+   * Returns a new DStream by unifying data of another DStream with this DStream.
+   * @param that Another DStream having the same interval (i.e., slideTime) as this DStream.
+   */
   def union(that: DStream[T]): DStream[T] = new UnionDStream[T](Array(this, that))
 
-  def slice(interval: Interval): Seq[RDD[T]] = {
+  /**
+   * Returns all the RDDs defined by the Interval object (both end times included)
+   */
+  protected[streaming] def slice(interval: Interval): Seq[RDD[T]] = {
     slice(interval.beginTime, interval.endTime)
   }
 
-  // Get all the RDDs between fromTime to toTime (both included)
+  /**
+   * Returns all the RDDs between 'fromTime' to 'toTime' (both included)
+   */
   def slice(fromTime: Time, toTime: Time): Seq[RDD[T]] = {
     val rdds = new ArrayBuffer[RDD[T]]()
     var time = toTime.floor(slideTime)
@@ -540,20 +612,26 @@ extends Serializable with Logging {
     rdds.toSeq
   }
 
+  /**
+   * Saves each RDD in this DStream as a Sequence file of serialized objects.
+   */
   def saveAsObjectFiles(prefix: String, suffix: String = "") {
     val saveFunc = (rdd: RDD[T], time: Time) => {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsObjectFile(file)
     }
-    this.foreachRDD(saveFunc)
+    this.foreach(saveFunc)
   }
 
+  /**
+   * Saves each RDD in this DStream as at text file, using string representation of elements.
+   */
   def saveAsTextFiles(prefix: String, suffix: String = "") {
     val saveFunc = (rdd: RDD[T], time: Time) => {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsTextFile(file)
     }
-    this.foreachRDD(saveFunc)
+    this.foreach(saveFunc)
   }
 
   def register() {
@@ -561,6 +639,8 @@ extends Serializable with Logging {
   }
 }
 
+private[streaming]
+case class DStreamCheckpointData(rdds: HashMap[Time, Any])
 
 abstract class InputDStream[T: ClassManifest] (@transient ssc_ : StreamingContext)
   extends DStream[T](ssc_) {
@@ -583,6 +663,7 @@ abstract class InputDStream[T: ClassManifest] (@transient ssc_ : StreamingContex
  * TODO
  */
 
+private[streaming]
 class MappedDStream[T: ClassManifest, U: ClassManifest] (
     parent: DStream[T],
     mapFunc: T => U
@@ -602,6 +683,7 @@ class MappedDStream[T: ClassManifest, U: ClassManifest] (
  * TODO
  */
 
+private[streaming]
 class FlatMappedDStream[T: ClassManifest, U: ClassManifest](
     parent: DStream[T],
     flatMapFunc: T => Traversable[U]
@@ -621,6 +703,7 @@ class FlatMappedDStream[T: ClassManifest, U: ClassManifest](
  * TODO
  */
 
+private[streaming]
 class FilteredDStream[T: ClassManifest](
     parent: DStream[T],
     filterFunc: T => Boolean
@@ -640,9 +723,11 @@ class FilteredDStream[T: ClassManifest](
  * TODO
  */
 
+private[streaming]
 class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
     parent: DStream[T],
-    mapPartFunc: Iterator[T] => Iterator[U]
+    mapPartFunc: Iterator[T] => Iterator[U],
+    preservePartitioning: Boolean
   ) extends DStream[U](parent.ssc) {
 
   override def dependencies = List(parent)
@@ -650,7 +735,7 @@ class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
   override def slideTime: Time = parent.slideTime
 
   override def compute(validTime: Time): Option[RDD[U]] = {
-    parent.getOrCompute(validTime).map(_.mapPartitions[U](mapPartFunc))
+    parent.getOrCompute(validTime).map(_.mapPartitions[U](mapPartFunc, preservePartitioning))
   }
 }
 
@@ -659,6 +744,7 @@ class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
  * TODO
  */
 
+private[streaming]
 class GlommedDStream[T: ClassManifest](parent: DStream[T])
   extends DStream[Array[T]](parent.ssc) {
 
@@ -676,6 +762,7 @@ class GlommedDStream[T: ClassManifest](parent: DStream[T])
  * TODO
  */
 
+private[streaming]
 class ShuffledDStream[K: ClassManifest, V: ClassManifest, C: ClassManifest](
     parent: DStream[(K,V)],
     createCombiner: V => C,
@@ -702,6 +789,7 @@ class ShuffledDStream[K: ClassManifest, V: ClassManifest, C: ClassManifest](
  * TODO
  */
 
+private[streaming]
 class MapValuesDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
     parent: DStream[(K, V)],
     mapValueFunc: V => U
@@ -720,7 +808,7 @@ class MapValuesDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
 /**
  * TODO
  */
-
+private[streaming]
 class FlatMapValuesDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
     parent: DStream[(K, V)],
     flatMapValueFunc: V => TraversableOnce[U]
@@ -779,38 +867,8 @@ class UnionDStream[T: ClassManifest](parents: Array[DStream[T]])
  * TODO
  */
 
-class PerElementForEachDStream[T: ClassManifest] (
-    parent: DStream[T],
-    foreachFunc: T => Unit
-  ) extends DStream[Unit](parent.ssc) {
-  
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[Unit]] = None 
-
-  override def generateJob(time: Time): Option[Job] = {
-    parent.getOrCompute(time) match {
-      case Some(rdd) =>
-        val jobFunc = () => {
-          val sparkJobFunc = { 
-            (iterator: Iterator[T]) => iterator.foreach(foreachFunc) 
-          } 
-          ssc.sc.runJob(rdd, sparkJobFunc)
-        }
-        Some(new Job(time, jobFunc))
-      case None => None
-    }
-  }
-}
-
-
-/**
- * TODO
- */
-
-class PerRDDForEachDStream[T: ClassManifest] (
+private[streaming]
+class ForEachDStream[T: ClassManifest] (
     parent: DStream[T],
     foreachFunc: (RDD[T], Time) => Unit
   ) extends DStream[Unit](parent.ssc) {
@@ -838,6 +896,7 @@ class PerRDDForEachDStream[T: ClassManifest] (
  * TODO
  */
 
+private[streaming]
 class TransformedDStream[T: ClassManifest, U: ClassManifest] (
     parent: DStream[T],
     transformFunc: (RDD[T], Time) => RDD[U]
diff --git a/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala b/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
index 2959ce4540..5ac7e5b08e 100644
--- a/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
@@ -79,7 +79,7 @@ class SparkFlumeEvent() extends Externalizable {
   }
 }
 
-object SparkFlumeEvent {
+private[streaming] object SparkFlumeEvent {
   def fromAvroFlumeEvent(in : AvroFlumeEvent) : SparkFlumeEvent = {
     val event = new SparkFlumeEvent
     event.event = in
diff --git a/streaming/src/main/scala/spark/streaming/Interval.scala b/streaming/src/main/scala/spark/streaming/Interval.scala
index ffb7725ac9..fa0b7ce19d 100644
--- a/streaming/src/main/scala/spark/streaming/Interval.scala
+++ b/streaming/src/main/scala/spark/streaming/Interval.scala
@@ -1,5 +1,6 @@
 package spark.streaming
 
+private[streaming]
 case class Interval(beginTime: Time, endTime: Time) {
   def this(beginMs: Long, endMs: Long) = this(Time(beginMs), new Time(endMs))
   
diff --git a/streaming/src/main/scala/spark/streaming/Job.scala b/streaming/src/main/scala/spark/streaming/Job.scala
index 0bcb6fd8dc..67bd8388bc 100644
--- a/streaming/src/main/scala/spark/streaming/Job.scala
+++ b/streaming/src/main/scala/spark/streaming/Job.scala
@@ -2,6 +2,7 @@ package spark.streaming
 
 import java.util.concurrent.atomic.AtomicLong
 
+private[streaming]
 class Job(val time: Time, func: () => _) {
   val id = Job.getNewId()
   def run(): Long = {
@@ -14,6 +15,7 @@ class Job(val time: Time, func: () => _) {
   override def toString = "streaming job " + id + " @ " + time 
 }
 
+private[streaming]
 object Job {
   val id = new AtomicLong(0)
 
diff --git a/streaming/src/main/scala/spark/streaming/JobManager.scala b/streaming/src/main/scala/spark/streaming/JobManager.scala
index 9bf9251519..fda7264a27 100644
--- a/streaming/src/main/scala/spark/streaming/JobManager.scala
+++ b/streaming/src/main/scala/spark/streaming/JobManager.scala
@@ -5,6 +5,7 @@ import spark.SparkEnv
 import java.util.concurrent.Executors
 
 
+private[streaming]
 class JobManager(ssc: StreamingContext, numThreads: Int = 1) extends Logging {
   
   class JobHandler(ssc: StreamingContext, job: Job) extends Runnable {
diff --git a/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala b/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
index 4e4e9fc942..4bf13dd50c 100644
--- a/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
@@ -40,10 +40,10 @@ abstract class NetworkInputDStream[T: ClassManifest](@transient ssc_ : Streaming
 }
 
 
-sealed trait NetworkReceiverMessage
-case class StopReceiver(msg: String) extends NetworkReceiverMessage
-case class ReportBlock(blockId: String, metadata: Any) extends NetworkReceiverMessage
-case class ReportError(msg: String) extends NetworkReceiverMessage
+private[streaming] sealed trait NetworkReceiverMessage
+private[streaming] case class StopReceiver(msg: String) extends NetworkReceiverMessage
+private[streaming] case class ReportBlock(blockId: String, metadata: Any) extends NetworkReceiverMessage
+private[streaming] case class ReportError(msg: String) extends NetworkReceiverMessage
 
 abstract class NetworkReceiver[T: ClassManifest](val streamId: Int) extends Serializable with Logging {
 
diff --git a/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala b/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
index b421f795ee..658498dfc1 100644
--- a/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
+++ b/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
@@ -11,10 +11,10 @@ import akka.pattern.ask
 import akka.util.duration._
 import akka.dispatch._
 
-trait NetworkInputTrackerMessage 
-case class RegisterReceiver(streamId: Int, receiverActor: ActorRef) extends NetworkInputTrackerMessage
-case class AddBlocks(streamId: Int, blockIds: Seq[String], metadata: Any) extends NetworkInputTrackerMessage
-case class DeregisterReceiver(streamId: Int, msg: String) extends NetworkInputTrackerMessage
+private[streaming] sealed trait NetworkInputTrackerMessage
+private[streaming] case class RegisterReceiver(streamId: Int, receiverActor: ActorRef) extends NetworkInputTrackerMessage
+private[streaming] case class AddBlocks(streamId: Int, blockIds: Seq[String], metadata: Any) extends NetworkInputTrackerMessage
+private[streaming] case class DeregisterReceiver(streamId: Int, msg: String) extends NetworkInputTrackerMessage
 
 
 class NetworkInputTracker(
diff --git a/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala b/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
index 720e63bba0..f9fef14196 100644
--- a/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
+++ b/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
@@ -281,7 +281,7 @@ extends Serializable {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsHadoopFile(file, keyClass, valueClass, outputFormatClass, conf)
     }
-    self.foreachRDD(saveFunc)
+    self.foreach(saveFunc)
   }
 
   def saveAsNewAPIHadoopFiles[F <: NewOutputFormat[K, V]](
@@ -303,7 +303,7 @@ extends Serializable {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsNewAPIHadoopFile(file, keyClass, valueClass, outputFormatClass, conf)
     }
-    self.foreachRDD(saveFunc)
+    self.foreach(saveFunc)
   }
 
   private def getKeyClass() = implicitly[ClassManifest[K]].erasure
diff --git a/streaming/src/main/scala/spark/streaming/Scheduler.scala b/streaming/src/main/scala/spark/streaming/Scheduler.scala
index 014021be61..fd1fa77a24 100644
--- a/streaming/src/main/scala/spark/streaming/Scheduler.scala
+++ b/streaming/src/main/scala/spark/streaming/Scheduler.scala
@@ -7,11 +7,8 @@ import spark.Logging
 import scala.collection.mutable.HashMap
 
 
-sealed trait SchedulerMessage
-case class InputGenerated(inputName: String, interval: Interval, reference: AnyRef = null) extends SchedulerMessage
-
-class Scheduler(ssc: StreamingContext)
-extends Logging {
+private[streaming]
+class Scheduler(ssc: StreamingContext) extends Logging {
 
   initLogging()
 
diff --git a/streaming/src/main/scala/spark/streaming/StreamingContext.scala b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
index ce47bcb2da..998fea849f 100644
--- a/streaming/src/main/scala/spark/streaming/StreamingContext.scala
+++ b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
@@ -48,7 +48,7 @@ class StreamingContext private (
     this(StreamingContext.createNewSparkContext(master, frameworkName), null, batchDuration)
 
   /**
-   * Recreates the StreamingContext from a checkpoint file.
+   * Re-creates a StreamingContext from a checkpoint file.
    * @param path Path either to the directory that was specified as the checkpoint directory, or
    *             to the checkpoint file 'graph' or 'graph.bk'.
    */
@@ -61,7 +61,7 @@ class StreamingContext private (
       "both SparkContext and checkpoint as null")
   }
 
-  val isCheckpointPresent = (cp_ != null)
+  protected[streaming] val isCheckpointPresent = (cp_ != null)
 
   val sc: SparkContext = {
     if (isCheckpointPresent) {
@@ -71,9 +71,9 @@ class StreamingContext private (
     }
   }
 
-  val env = SparkEnv.get
+  protected[streaming] val env = SparkEnv.get
 
-  val graph: DStreamGraph = {
+  protected[streaming] val graph: DStreamGraph = {
     if (isCheckpointPresent) {
       cp_.graph.setContext(this)
       cp_.graph.restoreCheckpointData()
@@ -86,10 +86,10 @@ class StreamingContext private (
     }
   }
 
-  private[streaming] val nextNetworkInputStreamId = new AtomicInteger(0)
-  private[streaming] var networkInputTracker: NetworkInputTracker = null
+  protected[streaming] val nextNetworkInputStreamId = new AtomicInteger(0)
+  protected[streaming] var networkInputTracker: NetworkInputTracker = null
 
-  private[streaming] var checkpointDir: String = {
+  protected[streaming] var checkpointDir: String = {
     if (isCheckpointPresent) {
       sc.setCheckpointDir(StreamingContext.getSparkCheckpointDir(cp_.checkpointDir), true)
       cp_.checkpointDir
@@ -98,9 +98,9 @@ class StreamingContext private (
     }
   }
 
-  private[streaming] var checkpointInterval: Time = if (isCheckpointPresent) cp_.checkpointInterval else null
-  private[streaming] var receiverJobThread: Thread = null
-  private[streaming] var scheduler: Scheduler = null
+  protected[streaming] var checkpointInterval: Time = if (isCheckpointPresent) cp_.checkpointInterval else null
+  protected[streaming] var receiverJobThread: Thread = null
+  protected[streaming] var scheduler: Scheduler = null
 
   def remember(duration: Time) {
     graph.remember(duration)
@@ -117,11 +117,11 @@ class StreamingContext private (
     }
   }
 
-  private[streaming] def getInitialCheckpoint(): Checkpoint = {
+  protected[streaming] def getInitialCheckpoint(): Checkpoint = {
     if (isCheckpointPresent) cp_ else null
   }
 
-  private[streaming] def getNewNetworkStreamId() = nextNetworkInputStreamId.getAndIncrement()
+  protected[streaming] def getNewNetworkStreamId() = nextNetworkInputStreamId.getAndIncrement()
 
  /**
    * Create an input stream that pulls messages form a Kafka Broker.
@@ -188,7 +188,7 @@ class StreamingContext private (
   }
 
   /**
-   * This function creates a input stream that monitors a Hadoop-compatible filesystem
+   * Creates a input stream that monitors a Hadoop-compatible filesystem
    * for new files and executes the necessary processing on them.
    */
   def fileStream[
@@ -206,7 +206,7 @@ class StreamingContext private (
   }
 
   /**
-   * This function create a input stream from an queue of RDDs. In each batch,
+   * Creates a input stream from an queue of RDDs. In each batch,
    * it will process either one or all of the RDDs returned by the queue
    */
   def queueStream[T: ClassManifest](
@@ -231,22 +231,21 @@ class StreamingContext private (
   }
 
   /**
-   * This function registers a InputDStream as an input stream that will be
-   * started (InputDStream.start() called) to get the input data streams.
+   * Registers an input stream that will be started (InputDStream.start() called) to get the
+   * input data.
    */
   def registerInputStream(inputStream: InputDStream[_]) {
     graph.addInputStream(inputStream)
   }
 
   /**
-   * This function registers a DStream as an output stream that will be
-   * computed every interval.
+   * Registers an output stream that will be computed every interval
    */
   def registerOutputStream(outputStream: DStream[_]) {
     graph.addOutputStream(outputStream)
   }
 
-  def validate() {
+  protected def validate() {
     assert(graph != null, "Graph is null")
     graph.validate()
 
@@ -304,7 +303,7 @@ class StreamingContext private (
 
 object StreamingContext {
 
-  def createNewSparkContext(master: String, frameworkName: String): SparkContext = {
+  protected[streaming] def createNewSparkContext(master: String, frameworkName: String): SparkContext = {
 
     // Set the default cleaner delay to an hour if not already set.
     // This should be sufficient for even 1 second interval.
@@ -318,7 +317,7 @@ object StreamingContext {
     new PairDStreamFunctions[K, V](stream)
   }
 
-  def rddToFileName[T](prefix: String, suffix: String, time: Time): String = {
+  protected[streaming] def rddToFileName[T](prefix: String, suffix: String, time: Time): String = {
     if (prefix == null) {
       time.millis.toString
     } else if (suffix == null || suffix.length ==0) {
@@ -328,7 +327,7 @@ object StreamingContext {
     }
   }
 
-  def getSparkCheckpointDir(sscCheckpointDir: String): String = {
+  protected[streaming] def getSparkCheckpointDir(sscCheckpointDir: String): String = {
     new Path(sscCheckpointDir, UUID.randomUUID.toString).toString
   }
 }
diff --git a/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala b/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
index 6cb2b4c042..7c4ee3b34c 100644
--- a/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
@@ -26,7 +26,7 @@ object GrepRaw {
     val rawStreams = (1 to numStreams).map(_ =>
       ssc.rawNetworkStream[String](host, port, StorageLevel.MEMORY_ONLY_SER_2)).toArray
     val union = new UnionDStream(rawStreams)
-    union.filter(_.contains("Alice")).count().foreachRDD(r =>
+    union.filter(_.contains("Alice")).count().foreach(r =>
       println("Grep count: " + r.collect().mkString))
     ssc.start()
   }
diff --git a/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala b/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
index fe4c2bf155..182dfd8a52 100644
--- a/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
@@ -38,7 +38,7 @@ object TopKWordCountRaw {
     val counts = union.mapPartitions(splitAndCountPartitions)
     val windowedCounts = counts.reduceByKeyAndWindow(add _, subtract _, Seconds(30), Seconds(1), 10)
     val partialTopKWindowedCounts = windowedCounts.mapPartitions(topK(_, k))
-    partialTopKWindowedCounts.foreachRDD(rdd => {
+    partialTopKWindowedCounts.foreach(rdd => {
       val collectedCounts = rdd.collect
       println("Collected " + collectedCounts.size + " words from partial top words") 
       println("Top " + k + " words are " + topK(collectedCounts.toIterator, k).mkString(","))
diff --git a/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala b/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
index a29c81d437..9bcd30f4d7 100644
--- a/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
@@ -36,7 +36,7 @@ object WordCountRaw {
     val union = new UnionDStream(lines.toArray)
     val counts = union.mapPartitions(splitAndCountPartitions)
     val windowedCounts = counts.reduceByKeyAndWindow(add _, subtract _, Seconds(30), Seconds(1), 10)
-    windowedCounts.foreachRDD(r => println("# unique words = " + r.count()))
+    windowedCounts.foreach(r => println("# unique words = " + r.count()))
 
     ssc.start()
   }
diff --git a/streaming/src/main/scala/spark/streaming/examples/clickstream/PageViewStream.scala b/streaming/src/main/scala/spark/streaming/examples/clickstream/PageViewStream.scala
index 68be6b7893..a191321d91 100644
--- a/streaming/src/main/scala/spark/streaming/examples/clickstream/PageViewStream.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/clickstream/PageViewStream.scala
@@ -72,7 +72,7 @@ object PageViewStream {
       case "popularUsersSeen" =>
         // Look for users in our existing dataset and print it out if we have a match
         pageViews.map(view => (view.userID, 1))
-          .foreachRDD((rdd, time) => rdd.join(userList)
+          .foreach((rdd, time) => rdd.join(userList)
             .map(_._2._2)
             .take(10)
             .foreach(u => println("Saw user %s at time %s".format(u, time))))
diff --git a/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala b/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
index 8cc2f8ccfc..a44f738957 100644
--- a/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
+++ b/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
@@ -35,7 +35,7 @@ class TestInputStream[T: ClassManifest](ssc_ : StreamingContext, input: Seq[Seq[
  * ArrayBuffer. This buffer is wiped clean on being restored from checkpoint.
  */
 class TestOutputStream[T: ClassManifest](parent: DStream[T], val output: ArrayBuffer[Seq[T]])
-  extends PerRDDForEachDStream[T](parent, (rdd: RDD[T], t: Time) => {
+  extends ForEachDStream[T](parent, (rdd: RDD[T], t: Time) => {
     val collected = rdd.collect()
     output += collected
   }) {
-- 
cgit v1.2.3


From 7e0271b4387eaf27cd96f3057ce2465b1271a480 Mon Sep 17 00:00:00 2001
From: Tathagata Das <tathagata.das1565@gmail.com>
Date: Sun, 30 Dec 2012 15:19:55 -0800
Subject: Refactored a whole lot to push all DStreams into the
 spark.streaming.dstream package.

---
 core/src/main/scala/spark/rdd/ShuffledRDD.scala    |   1 +
 .../scala/spark/streaming/CoGroupedDStream.scala   |  38 ---
 .../spark/streaming/ConstantInputDStream.scala     |  18 --
 .../src/main/scala/spark/streaming/DStream.scala   | 276 +--------------------
 .../main/scala/spark/streaming/DStreamGraph.scala  |   1 +
 .../main/scala/spark/streaming/DataHandler.scala   |  83 -------
 .../scala/spark/streaming/FileInputDStream.scala   | 109 --------
 .../scala/spark/streaming/FlumeInputDStream.scala  | 130 ----------
 .../spark/streaming/NetworkInputDStream.scala      | 156 ------------
 .../spark/streaming/NetworkInputTracker.scala      |   2 +
 .../spark/streaming/PairDStreamFunctions.scala     |   7 +-
 .../scala/spark/streaming/QueueInputDStream.scala  |  40 ---
 .../scala/spark/streaming/RawInputDStream.scala    |  85 -------
 .../spark/streaming/ReducedWindowedDStream.scala   | 149 -----------
 .../src/main/scala/spark/streaming/Scheduler.scala |   3 -
 .../scala/spark/streaming/SocketInputDStream.scala | 107 --------
 .../main/scala/spark/streaming/StateDStream.scala  |  84 -------
 .../scala/spark/streaming/StreamingContext.scala   |  13 +-
 .../src/main/scala/spark/streaming/Time.scala      |  11 +-
 .../scala/spark/streaming/WindowedDStream.scala    |  39 ---
 .../spark/streaming/dstream/CoGroupedDStream.scala |  39 +++
 .../streaming/dstream/ConstantInputDStream.scala   |  19 ++
 .../spark/streaming/dstream/DataHandler.scala      |  83 +++++++
 .../spark/streaming/dstream/FileInputDStream.scala | 110 ++++++++
 .../spark/streaming/dstream/FilteredDStream.scala  |  21 ++
 .../streaming/dstream/FlatMapValuedDStream.scala   |  20 ++
 .../streaming/dstream/FlatMappedDStream.scala      |  20 ++
 .../streaming/dstream/FlumeInputDStream.scala      | 135 ++++++++++
 .../spark/streaming/dstream/ForEachDStream.scala   |  28 +++
 .../spark/streaming/dstream/GlommedDStream.scala   |  17 ++
 .../spark/streaming/dstream/InputDStream.scala     |  19 ++
 .../streaming/dstream/KafkaInputDStream.scala      | 197 +++++++++++++++
 .../streaming/dstream/MapPartitionedDStream.scala  |  21 ++
 .../spark/streaming/dstream/MapValuedDStream.scala |  21 ++
 .../spark/streaming/dstream/MappedDStream.scala    |  20 ++
 .../streaming/dstream/NetworkInputDStream.scala    | 157 ++++++++++++
 .../streaming/dstream/QueueInputDStream.scala      |  41 +++
 .../spark/streaming/dstream/RawInputDStream.scala  |  88 +++++++
 .../streaming/dstream/ReducedWindowedDStream.scala | 148 +++++++++++
 .../spark/streaming/dstream/ShuffledDStream.scala  |  27 ++
 .../streaming/dstream/SocketInputDStream.scala     | 103 ++++++++
 .../spark/streaming/dstream/StateDStream.scala     |  83 +++++++
 .../streaming/dstream/TransformedDStream.scala     |  19 ++
 .../spark/streaming/dstream/UnionDStream.scala     |  39 +++
 .../spark/streaming/dstream/WindowedDStream.scala  |  40 +++
 .../scala/spark/streaming/examples/GrepRaw.scala   |   2 +-
 .../streaming/examples/TopKWordCountRaw.scala      |   2 +-
 .../spark/streaming/examples/WordCountRaw.scala    |   2 +-
 .../spark/streaming/input/KafkaInputDStream.scala  | 193 --------------
 .../scala/spark/streaming/CheckpointSuite.scala    |   2 +-
 .../test/scala/spark/streaming/FailureSuite.scala  |   2 +-
 .../scala/spark/streaming/InputStreamsSuite.scala  |   1 +
 .../test/scala/spark/streaming/TestSuiteBase.scala |  48 +++-
 .../spark/streaming/WindowOperationsSuite.scala    |  12 +-
 54 files changed, 1600 insertions(+), 1531 deletions(-)
 delete mode 100644 streaming/src/main/scala/spark/streaming/CoGroupedDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/ConstantInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/DataHandler.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/FileInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/QueueInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/RawInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/ReducedWindowedDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/SocketInputDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/StateDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/WindowedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/ConstantInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/DataHandler.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/FilteredDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/FlatMapValuedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/FlatMappedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/ForEachDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/GlommedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/InputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/MapPartitionedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/MapValuedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/MappedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/NetworkInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/QueueInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/ShuffledDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/TransformedDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
 create mode 100644 streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
 delete mode 100644 streaming/src/main/scala/spark/streaming/input/KafkaInputDStream.scala

(limited to 'streaming')

diff --git a/core/src/main/scala/spark/rdd/ShuffledRDD.scala b/core/src/main/scala/spark/rdd/ShuffledRDD.scala
index f40b56be64..1b219473e0 100644
--- a/core/src/main/scala/spark/rdd/ShuffledRDD.scala
+++ b/core/src/main/scala/spark/rdd/ShuffledRDD.scala
@@ -1,6 +1,7 @@
 package spark.rdd
 
 import spark.{Partitioner, RDD, SparkEnv, ShuffleDependency, Split, TaskContext}
+import spark.SparkContext._
 
 private[spark] class ShuffledRDDSplit(val idx: Int) extends Split {
   override val index = idx
diff --git a/streaming/src/main/scala/spark/streaming/CoGroupedDStream.scala b/streaming/src/main/scala/spark/streaming/CoGroupedDStream.scala
deleted file mode 100644
index 61d088eddb..0000000000
--- a/streaming/src/main/scala/spark/streaming/CoGroupedDStream.scala
+++ /dev/null
@@ -1,38 +0,0 @@
-package spark.streaming
-
-import spark.{RDD, Partitioner}
-import spark.rdd.CoGroupedRDD
-
-class CoGroupedDStream[K : ClassManifest](
-    parents: Seq[DStream[(_, _)]],
-    partitioner: Partitioner
-  ) extends DStream[(K, Seq[Seq[_]])](parents.head.ssc) {
-
-  if (parents.length == 0) {
-    throw new IllegalArgumentException("Empty array of parents")
-  }
-
-  if (parents.map(_.ssc).distinct.size > 1) {
-    throw new IllegalArgumentException("Array of parents have different StreamingContexts")
-  }
-
-  if (parents.map(_.slideTime).distinct.size > 1) {
-    throw new IllegalArgumentException("Array of parents have different slide times")
-  }
-
-  override def dependencies = parents.toList
-
-  override def slideTime = parents.head.slideTime
-
-  override def compute(validTime: Time): Option[RDD[(K, Seq[Seq[_]])]] = {
-    val part = partitioner
-    val rdds = parents.flatMap(_.getOrCompute(validTime))
-    if (rdds.size > 0) {
-      val q = new CoGroupedRDD[K](rdds, part)
-      Some(q)
-    } else {
-      None
-    }
-  }
-
-}
diff --git a/streaming/src/main/scala/spark/streaming/ConstantInputDStream.scala b/streaming/src/main/scala/spark/streaming/ConstantInputDStream.scala
deleted file mode 100644
index 80150708fd..0000000000
--- a/streaming/src/main/scala/spark/streaming/ConstantInputDStream.scala
+++ /dev/null
@@ -1,18 +0,0 @@
-package spark.streaming
-
-import spark.RDD
-
-/**
- * An input stream that always returns the same RDD on each timestep. Useful for testing.
- */
-class ConstantInputDStream[T: ClassManifest](ssc_ : StreamingContext, rdd: RDD[T])
-  extends InputDStream[T](ssc_) {
-
-  override def start() {}
-
-  override def stop() {}
-
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    Some(rdd)
-  }
-}
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/DStream.scala b/streaming/src/main/scala/spark/streaming/DStream.scala
index 3834b57ed3..292ad3b9f9 100644
--- a/streaming/src/main/scala/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/spark/streaming/DStream.scala
@@ -1,17 +1,15 @@
 package spark.streaming
 
+import spark.streaming.dstream._
 import StreamingContext._
 import Time._
 
-import spark._
-import spark.SparkContext._
-import spark.rdd._
+import spark.{RDD, Logging}
 import spark.storage.StorageLevel
 
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashMap
 
-import java.util.concurrent.ArrayBlockingQueue
 import java.io.{ObjectInputStream, IOException, ObjectOutputStream}
 
 import org.apache.hadoop.fs.Path
@@ -197,7 +195,7 @@ abstract class DStream[T: ClassManifest] (
         "than " + rememberDuration.milliseconds + " milliseconds. But the Spark's metadata cleanup" +
         "delay is set to " + (metadataCleanerDelay / 60.0) + " minutes, which is not sufficient. Please set " +
         "the Java property 'spark.cleaner.delay' to more than " +
-        math.ceil(rememberDuration.millis.toDouble / 60000.0).toInt + " minutes."
+        math.ceil(rememberDuration.milliseconds.toDouble / 60000.0).toInt + " minutes."
     )
 
     dependencies.foreach(_.validate())
@@ -642,271 +640,3 @@ abstract class DStream[T: ClassManifest] (
 private[streaming]
 case class DStreamCheckpointData(rdds: HashMap[Time, Any])
 
-abstract class InputDStream[T: ClassManifest] (@transient ssc_ : StreamingContext)
-  extends DStream[T](ssc_) {
-  
-  override def dependencies = List()
-
-  override def slideTime = {
-    if (ssc == null) throw new Exception("ssc is null")
-    if (ssc.graph.batchDuration == null) throw new Exception("batchDuration is null")
-    ssc.graph.batchDuration
-  }
-  
-  def start()  
-  
-  def stop()
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class MappedDStream[T: ClassManifest, U: ClassManifest] (
-    parent: DStream[T],
-    mapFunc: T => U
-  ) extends DStream[U](parent.ssc) {
-  
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[U]] = {
-    parent.getOrCompute(validTime).map(_.map[U](mapFunc))
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class FlatMappedDStream[T: ClassManifest, U: ClassManifest](
-    parent: DStream[T],
-    flatMapFunc: T => Traversable[U]
-  ) extends DStream[U](parent.ssc) {
-  
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[U]] = {
-    parent.getOrCompute(validTime).map(_.flatMap(flatMapFunc))
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class FilteredDStream[T: ClassManifest](
-    parent: DStream[T],
-    filterFunc: T => Boolean
-  ) extends DStream[T](parent.ssc) {
-  
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    parent.getOrCompute(validTime).map(_.filter(filterFunc))
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
-    parent: DStream[T],
-    mapPartFunc: Iterator[T] => Iterator[U],
-    preservePartitioning: Boolean
-  ) extends DStream[U](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[U]] = {
-    parent.getOrCompute(validTime).map(_.mapPartitions[U](mapPartFunc, preservePartitioning))
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class GlommedDStream[T: ClassManifest](parent: DStream[T])
-  extends DStream[Array[T]](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[Array[T]]] = {
-    parent.getOrCompute(validTime).map(_.glom())
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class ShuffledDStream[K: ClassManifest, V: ClassManifest, C: ClassManifest](
-    parent: DStream[(K,V)],
-    createCombiner: V => C,
-    mergeValue: (C, V) => C,
-    mergeCombiner: (C, C) => C,
-    partitioner: Partitioner
-  ) extends DStream [(K,C)] (parent.ssc) {
-  
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[(K,C)]] = {
-    parent.getOrCompute(validTime) match {
-      case Some(rdd) =>
-        Some(rdd.combineByKey[C](createCombiner, mergeValue, mergeCombiner, partitioner))
-      case None => None
-    }
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class MapValuesDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
-    parent: DStream[(K, V)],
-    mapValueFunc: V => U
-  ) extends DStream[(K, U)](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[(K, U)]] = {
-    parent.getOrCompute(validTime).map(_.mapValues[U](mapValueFunc))
-  }
-}
-
-
-/**
- * TODO
- */
-private[streaming]
-class FlatMapValuesDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
-    parent: DStream[(K, V)],
-    flatMapValueFunc: V => TraversableOnce[U]
-  ) extends DStream[(K, U)](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[(K, U)]] = {
-    parent.getOrCompute(validTime).map(_.flatMapValues[U](flatMapValueFunc))
-  }
-}
-
-
-
-/**
- * TODO
- */
-
-class UnionDStream[T: ClassManifest](parents: Array[DStream[T]])
-  extends DStream[T](parents.head.ssc) {
-
-  if (parents.length == 0) {
-    throw new IllegalArgumentException("Empty array of parents")
-  }
-
-  if (parents.map(_.ssc).distinct.size > 1) {
-    throw new IllegalArgumentException("Array of parents have different StreamingContexts")
-  }
-  
-  if (parents.map(_.slideTime).distinct.size > 1) {
-    throw new IllegalArgumentException("Array of parents have different slide times")
-  }
-
-  override def dependencies = parents.toList
-
-  override def slideTime: Time = parents.head.slideTime
-
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    val rdds = new ArrayBuffer[RDD[T]]()
-    parents.map(_.getOrCompute(validTime)).foreach(_ match {
-      case Some(rdd) => rdds += rdd
-      case None => throw new Exception("Could not generate RDD from a parent for unifying at time " + validTime)
-    })
-    if (rdds.size > 0) {
-      Some(new UnionRDD(ssc.sc, rdds))
-    } else {
-      None
-    }
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class ForEachDStream[T: ClassManifest] (
-    parent: DStream[T],
-    foreachFunc: (RDD[T], Time) => Unit
-  ) extends DStream[Unit](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[Unit]] = None 
-
-  override def generateJob(time: Time): Option[Job] = {
-    parent.getOrCompute(time) match {
-      case Some(rdd) =>
-        val jobFunc = () => {
-          foreachFunc(rdd, time)
-        }
-        Some(new Job(time, jobFunc))
-      case None => None
-    }
-  }
-}
-
-
-/**
- * TODO
- */
-
-private[streaming]
-class TransformedDStream[T: ClassManifest, U: ClassManifest] (
-    parent: DStream[T],
-    transformFunc: (RDD[T], Time) => RDD[U]
-  ) extends DStream[U](parent.ssc) {
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = parent.slideTime
-
-  override def compute(validTime: Time): Option[RDD[U]] = {
-    parent.getOrCompute(validTime).map(transformFunc(_, validTime))
-  }
-}
diff --git a/streaming/src/main/scala/spark/streaming/DStreamGraph.scala b/streaming/src/main/scala/spark/streaming/DStreamGraph.scala
index d0a9ade61d..c72429370e 100644
--- a/streaming/src/main/scala/spark/streaming/DStreamGraph.scala
+++ b/streaming/src/main/scala/spark/streaming/DStreamGraph.scala
@@ -1,5 +1,6 @@
 package spark.streaming
 
+import dstream.InputDStream
 import java.io.{ObjectInputStream, IOException, ObjectOutputStream}
 import collection.mutable.ArrayBuffer
 import spark.Logging
diff --git a/streaming/src/main/scala/spark/streaming/DataHandler.scala b/streaming/src/main/scala/spark/streaming/DataHandler.scala
deleted file mode 100644
index 05f307a8d1..0000000000
--- a/streaming/src/main/scala/spark/streaming/DataHandler.scala
+++ /dev/null
@@ -1,83 +0,0 @@
-package spark.streaming
-
-import java.util.concurrent.ArrayBlockingQueue
-import scala.collection.mutable.ArrayBuffer
-import spark.Logging
-import spark.streaming.util.{RecurringTimer, SystemClock}
-import spark.storage.StorageLevel
-
-
-/**
-   * This is a helper object that manages the data received from the socket. It divides
-   * the object received into small batches of 100s of milliseconds, pushes them as
-   * blocks into the block manager and reports the block IDs to the network input
-   * tracker. It starts two threads, one to periodically start a new batch and prepare
-   * the previous batch of as a block, the other to push the blocks into the block
-   * manager.
-   */
-  class DataHandler[T](receiver: NetworkReceiver[T], storageLevel: StorageLevel) 
-    extends Serializable with Logging {
-    
-    case class Block(id: String, iterator: Iterator[T], metadata: Any = null)
-
-    val clock = new SystemClock()
-    val blockInterval = 200L
-    val blockIntervalTimer = new RecurringTimer(clock, blockInterval, updateCurrentBuffer)
-    val blockStorageLevel = storageLevel
-    val blocksForPushing = new ArrayBlockingQueue[Block](1000)
-    val blockPushingThread = new Thread() { override def run() { keepPushingBlocks() } }
-
-    var currentBuffer = new ArrayBuffer[T]
-
-    def createBlock(blockId: String, iterator: Iterator[T]) : Block = {
-      new Block(blockId, iterator)
-    }
-
-    def start() {
-      blockIntervalTimer.start()
-      blockPushingThread.start()
-      logInfo("Data handler started")
-    }
-
-    def stop() {
-      blockIntervalTimer.stop()
-      blockPushingThread.interrupt()
-      logInfo("Data handler stopped")
-    }
-
-    def += (obj: T) {
-      currentBuffer += obj
-    }
-
-    def updateCurrentBuffer(time: Long) {
-      try {
-        val newBlockBuffer = currentBuffer
-        currentBuffer = new ArrayBuffer[T]
-        if (newBlockBuffer.size > 0) {
-          val blockId = "input-" + receiver.streamId + "- " + (time - blockInterval)
-          val newBlock = createBlock(blockId, newBlockBuffer.toIterator)
-          blocksForPushing.add(newBlock)
-        }
-      } catch {
-        case ie: InterruptedException =>
-          logInfo("Block interval timer thread interrupted")
-        case e: Exception =>
-          receiver.stop()
-      }
-    }
-
-    def keepPushingBlocks() {
-      logInfo("Block pushing thread started")
-      try {
-        while(true) {
-          val block = blocksForPushing.take()
-          receiver.pushBlock(block.id, block.iterator, block.metadata, storageLevel)
-        }
-      } catch {
-        case ie: InterruptedException =>
-          logInfo("Block pushing thread interrupted")
-        case e: Exception =>
-          receiver.stop()
-      }
-    }
-  }
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/FileInputDStream.scala b/streaming/src/main/scala/spark/streaming/FileInputDStream.scala
deleted file mode 100644
index 88856364d2..0000000000
--- a/streaming/src/main/scala/spark/streaming/FileInputDStream.scala
+++ /dev/null
@@ -1,109 +0,0 @@
-package spark.streaming
-
-import spark.RDD
-import spark.rdd.UnionRDD
-
-import org.apache.hadoop.fs.{FileSystem, Path, PathFilter}
-import org.apache.hadoop.conf.Configuration
-import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
-
-import scala.collection.mutable.HashSet
-
-
-class FileInputDStream[K: ClassManifest, V: ClassManifest, F <: NewInputFormat[K,V] : ClassManifest](
-    @transient ssc_ : StreamingContext,
-    directory: String,
-    filter: PathFilter = FileInputDStream.defaultPathFilter,
-    newFilesOnly: Boolean = true) 
-  extends InputDStream[(K, V)](ssc_) {
-
-  @transient private var path_ : Path = null
-  @transient private var fs_ : FileSystem = null
-
-  var lastModTime = 0L
-  val lastModTimeFiles = new HashSet[String]()
-
-  def path(): Path = {
-    if (path_ == null) path_ = new Path(directory)
-    path_
-  }
-
-  def fs(): FileSystem = {
-    if (fs_ == null) fs_ = path.getFileSystem(new Configuration())
-    fs_
-  }
-
-  override def start() {
-    if (newFilesOnly) {
-      lastModTime = System.currentTimeMillis()
-    } else {
-      lastModTime = 0
-    }
-  }
-  
-  override def stop() { }
-
-  /**
-   * Finds the files that were modified since the last time this method was called and makes
-   * a union RDD out of them. Note that this maintains the list of files that were processed
-   * in the latest modification time in the previous call to this method. This is because the
-   * modification time returned by the FileStatus API seems to return times only at the
-   * granularity of seconds. Hence, new files may have the same modification time as the
-   * latest modification time in the previous call to this method and the list of files
-   * maintained is used to filter the one that have been processed.
-   */
-  override def compute(validTime: Time): Option[RDD[(K, V)]] = {
-    // Create the filter for selecting new files
-    val newFilter = new PathFilter() {
-      var latestModTime = 0L
-      val latestModTimeFiles = new HashSet[String]()
-
-      def accept(path: Path): Boolean = {
-        if (!filter.accept(path)) {
-          return false
-        } else {
-          val modTime = fs.getFileStatus(path).getModificationTime()
-          if (modTime < lastModTime){
-            return false
-          } else if (modTime == lastModTime && lastModTimeFiles.contains(path.toString)) {
-            return false
-          }
-          if (modTime > latestModTime) {
-            latestModTime = modTime
-            latestModTimeFiles.clear()
-          }
-          latestModTimeFiles += path.toString
-          return true
-        }        
-      }
-    }
-
-    val newFiles = fs.listStatus(path, newFilter)
-    logInfo("New files: " + newFiles.map(_.getPath).mkString(", "))
-    if (newFiles.length > 0) {
-      // Update the modification time and the files processed for that modification time
-      if (lastModTime != newFilter.latestModTime) {
-        lastModTime = newFilter.latestModTime
-        lastModTimeFiles.clear()
-      }
-      lastModTimeFiles ++= newFilter.latestModTimeFiles
-    }
-    val newRDD = new UnionRDD(ssc.sc, newFiles.map(
-      file => ssc.sc.newAPIHadoopFile[K, V, F](file.getPath.toString)))
-    Some(newRDD)
-  }
-}
-
-object FileInputDStream {
-  val defaultPathFilter = new PathFilter with Serializable {
-    def accept(path: Path): Boolean = {
-      val file = path.getName()
-      if (file.startsWith(".") || file.endsWith("_tmp")) {
-        return false
-      } else {
-        return true
-      }
-    }
-  }
-}
-
diff --git a/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala b/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
deleted file mode 100644
index 5ac7e5b08e..0000000000
--- a/streaming/src/main/scala/spark/streaming/FlumeInputDStream.scala
+++ /dev/null
@@ -1,130 +0,0 @@
-package spark.streaming
-
-import java.io.{ObjectInput, ObjectOutput, Externalizable}
-import spark.storage.StorageLevel
-import org.apache.flume.source.avro.AvroSourceProtocol
-import org.apache.flume.source.avro.AvroFlumeEvent
-import org.apache.flume.source.avro.Status
-import org.apache.avro.ipc.specific.SpecificResponder
-import org.apache.avro.ipc.NettyServer
-import java.net.InetSocketAddress
-import collection.JavaConversions._
-import spark.Utils
-import java.nio.ByteBuffer
-
-class FlumeInputDStream[T: ClassManifest](
-  @transient ssc_ : StreamingContext,
-  host: String,
-  port: Int,
-  storageLevel: StorageLevel
-) extends NetworkInputDStream[SparkFlumeEvent](ssc_) {
-
-  override def createReceiver(): NetworkReceiver[SparkFlumeEvent] = {
-    new FlumeReceiver(id, host, port, storageLevel)
-  }
-}
-
-/**
- * A wrapper class for AvroFlumeEvent's with a custom serialization format.
- *
- * This is necessary because AvroFlumeEvent uses inner data structures
- * which are not serializable.
- */
-class SparkFlumeEvent() extends Externalizable {
-  var event : AvroFlumeEvent = new AvroFlumeEvent()
-
-  /* De-serialize from bytes. */
-  def readExternal(in: ObjectInput) {
-    val bodyLength = in.readInt()
-    val bodyBuff = new Array[Byte](bodyLength)
-    in.read(bodyBuff)
-
-    val numHeaders = in.readInt()
-    val headers = new java.util.HashMap[CharSequence, CharSequence]
-
-    for (i <- 0 until numHeaders) {
-      val keyLength = in.readInt()
-      val keyBuff = new Array[Byte](keyLength)
-      in.read(keyBuff)
-      val key : String = Utils.deserialize(keyBuff)
-
-      val valLength = in.readInt()
-      val valBuff = new Array[Byte](valLength)
-      in.read(valBuff)
-      val value : String = Utils.deserialize(valBuff)
-
-      headers.put(key, value)
-    }
-
-    event.setBody(ByteBuffer.wrap(bodyBuff))
-    event.setHeaders(headers)
-  }
-
-  /* Serialize to bytes. */
-  def writeExternal(out: ObjectOutput) {
-    val body = event.getBody.array()
-    out.writeInt(body.length)
-    out.write(body)
-
-    val numHeaders = event.getHeaders.size()
-    out.writeInt(numHeaders)
-    for ((k, v) <- event.getHeaders) {
-      val keyBuff = Utils.serialize(k.toString)
-      out.writeInt(keyBuff.length)
-      out.write(keyBuff)
-      val valBuff = Utils.serialize(v.toString)
-      out.writeInt(valBuff.length)
-      out.write(valBuff)
-    }
-  }
-}
-
-private[streaming] object SparkFlumeEvent {
-  def fromAvroFlumeEvent(in : AvroFlumeEvent) : SparkFlumeEvent = {
-    val event = new SparkFlumeEvent
-    event.event = in
-    event
-  }
-}
-
-/** A simple server that implements Flume's Avro protocol. */
-class FlumeEventServer(receiver : FlumeReceiver) extends AvroSourceProtocol {
-  override def append(event : AvroFlumeEvent) : Status = {
-    receiver.dataHandler += SparkFlumeEvent.fromAvroFlumeEvent(event)
-    Status.OK
-  }
-
-  override def appendBatch(events : java.util.List[AvroFlumeEvent]) : Status = {
-    events.foreach (event =>
-      receiver.dataHandler += SparkFlumeEvent.fromAvroFlumeEvent(event))
-    Status.OK
-  }
-}
-
-/** A NetworkReceiver which listens for events using the
-  * Flume Avro interface.*/
-class FlumeReceiver(
-      streamId: Int,
-      host: String,
-      port: Int,
-      storageLevel: StorageLevel
-      ) extends NetworkReceiver[SparkFlumeEvent](streamId) {
-
-  lazy val dataHandler = new DataHandler(this, storageLevel)
-
-  protected override def onStart() {
-    val responder = new SpecificResponder(
-      classOf[AvroSourceProtocol], new FlumeEventServer(this));
-    val server = new NettyServer(responder, new InetSocketAddress(host, port));
-    dataHandler.start()
-    server.start()
-    logInfo("Flume receiver started")
-  }
-
-  protected override def onStop() {
-    dataHandler.stop()
-    logInfo("Flume receiver stopped")
-  }
-
-  override def getLocationPreference = Some(host)
-}
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala b/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
deleted file mode 100644
index 4bf13dd50c..0000000000
--- a/streaming/src/main/scala/spark/streaming/NetworkInputDStream.scala
+++ /dev/null
@@ -1,156 +0,0 @@
-package spark.streaming
-
-import scala.collection.mutable.ArrayBuffer
-
-import spark.{Logging, SparkEnv, RDD}
-import spark.rdd.BlockRDD
-import spark.streaming.util.{RecurringTimer, SystemClock}
-import spark.storage.StorageLevel
-
-import java.nio.ByteBuffer
-
-import akka.actor.{Props, Actor}
-import akka.pattern.ask
-import akka.dispatch.Await
-import akka.util.duration._
-
-abstract class NetworkInputDStream[T: ClassManifest](@transient ssc_ : StreamingContext)
-  extends InputDStream[T](ssc_) {
-
-  // This is an unique identifier that is used to match the network receiver with the
-  // corresponding network input stream.
-  val id = ssc.getNewNetworkStreamId()
-
-  /**
-   * This method creates the receiver object that will be sent to the workers
-   * to receive data. This method needs to defined by any specific implementation
-   * of a NetworkInputDStream.
-   */
-  def createReceiver(): NetworkReceiver[T]
-
-  // Nothing to start or stop as both taken care of by the NetworkInputTracker.
-  def start() {}
-
-  def stop() {}
-
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    val blockIds = ssc.networkInputTracker.getBlockIds(id, validTime)    
-    Some(new BlockRDD[T](ssc.sc, blockIds))
-  }
-}
-
-
-private[streaming] sealed trait NetworkReceiverMessage
-private[streaming] case class StopReceiver(msg: String) extends NetworkReceiverMessage
-private[streaming] case class ReportBlock(blockId: String, metadata: Any) extends NetworkReceiverMessage
-private[streaming] case class ReportError(msg: String) extends NetworkReceiverMessage
-
-abstract class NetworkReceiver[T: ClassManifest](val streamId: Int) extends Serializable with Logging {
-
-  initLogging()
-
-  lazy protected val env = SparkEnv.get
-
-  lazy protected val actor = env.actorSystem.actorOf(
-    Props(new NetworkReceiverActor()), "NetworkReceiver-" + streamId)
-
-  lazy protected val receivingThread = Thread.currentThread()
-
-  /** This method will be called to start receiving data. */
-  protected def onStart()
-
-  /** This method will be called to stop receiving data. */
-  protected def onStop()
-
-  /** This method conveys a placement preference (hostname) for this receiver. */
-  def getLocationPreference() : Option[String] = None
-
-  /**
-   * This method starts the receiver. First is accesses all the lazy members to
-   * materialize them. Then it calls the user-defined onStart() method to start
-   * other threads, etc required to receiver the data.
-   */
-  def start() {
-    try {
-      // Access the lazy vals to materialize them
-      env
-      actor
-      receivingThread
-
-      // Call user-defined onStart()
-      onStart()
-    } catch {
-      case ie: InterruptedException =>
-        logInfo("Receiving thread interrupted")
-        //println("Receiving thread interrupted")
-      case e: Exception =>
-        stopOnError(e)
-    }
-  }
-
-  /**
-   * This method stops the receiver. First it interrupts the main receiving thread,
-   * that is, the thread that called receiver.start(). Then it calls the user-defined
-   * onStop() method to stop other threads and/or do cleanup.
-   */
-  def stop() {
-    receivingThread.interrupt()
-    onStop()
-    //TODO: terminate the actor
-  }
-
-  /**
-   * This method stops the receiver and reports to exception to the tracker.
-   * This should be called whenever an exception has happened on any thread
-   * of the receiver.
-   */
-  protected def stopOnError(e: Exception) {
-    logError("Error receiving data", e)
-    stop()
-    actor ! ReportError(e.toString)
-  }
-
-
-  /**
-   * This method pushes a block (as iterator of values) into the block manager.
-   */
-  def pushBlock(blockId: String, iterator: Iterator[T], metadata: Any, level: StorageLevel) {
-    val buffer = new ArrayBuffer[T] ++ iterator
-    env.blockManager.put(blockId, buffer.asInstanceOf[ArrayBuffer[Any]], level)
-
-    actor ! ReportBlock(blockId, metadata)
-  }
-
-  /**
-   * This method pushes a block (as bytes) into the block manager.
-   */
-  def pushBlock(blockId: String, bytes: ByteBuffer, metadata: Any, level: StorageLevel) {
-    env.blockManager.putBytes(blockId, bytes, level)
-    actor ! ReportBlock(blockId, metadata)
-  }
-
-  /** A helper actor that communicates with the NetworkInputTracker */
-  private class NetworkReceiverActor extends Actor {
-    logInfo("Attempting to register with tracker")
-    val ip = System.getProperty("spark.master.host", "localhost")
-    val port = System.getProperty("spark.master.port", "7077").toInt
-    val url = "akka://spark@%s:%s/user/NetworkInputTracker".format(ip, port)
-    val tracker = env.actorSystem.actorFor(url)
-    val timeout = 5.seconds
-
-    override def preStart() {
-      val future = tracker.ask(RegisterReceiver(streamId, self))(timeout)
-      Await.result(future, timeout)
-    }
-
-    override def receive() = {
-      case ReportBlock(blockId, metadata) =>
-        tracker ! AddBlocks(streamId, Array(blockId), metadata)
-      case ReportError(msg) =>
-        tracker ! DeregisterReceiver(streamId, msg)
-      case StopReceiver(msg) =>
-        stop()
-        tracker ! DeregisterReceiver(streamId, msg)
-    }
-  }
-}
diff --git a/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala b/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
index 658498dfc1..a6ab44271f 100644
--- a/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
+++ b/streaming/src/main/scala/spark/streaming/NetworkInputTracker.scala
@@ -1,5 +1,7 @@
 package spark.streaming
 
+import spark.streaming.dstream.{NetworkInputDStream, NetworkReceiver}
+import spark.streaming.dstream.{StopReceiver, ReportBlock, ReportError}
 import spark.Logging
 import spark.SparkEnv
 
diff --git a/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala b/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
index f9fef14196..b0a208e67f 100644
--- a/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
+++ b/streaming/src/main/scala/spark/streaming/PairDStreamFunctions.scala
@@ -1,6 +1,9 @@
 package spark.streaming
 
 import spark.streaming.StreamingContext._
+import spark.streaming.dstream.{ReducedWindowedDStream, StateDStream}
+import spark.streaming.dstream.{CoGroupedDStream, ShuffledDStream}
+import spark.streaming.dstream.{MapValuedDStream, FlatMapValuedDStream}
 
 import spark.{Manifests, RDD, Partitioner, HashPartitioner}
 import spark.SparkContext._
@@ -218,13 +221,13 @@ extends Serializable {
 
 
   def mapValues[U: ClassManifest](mapValuesFunc: V => U): DStream[(K, U)] = {
-    new MapValuesDStream[K, V, U](self, mapValuesFunc)
+    new MapValuedDStream[K, V, U](self, mapValuesFunc)
   }
 
   def flatMapValues[U: ClassManifest](
       flatMapValuesFunc: V => TraversableOnce[U]
     ): DStream[(K, U)] = {
-    new FlatMapValuesDStream[K, V, U](self, flatMapValuesFunc)
+    new FlatMapValuedDStream[K, V, U](self, flatMapValuesFunc)
   }
 
   def cogroup[W: ClassManifest](other: DStream[(K, W)]): DStream[(K, (Seq[V], Seq[W]))] = {
diff --git a/streaming/src/main/scala/spark/streaming/QueueInputDStream.scala b/streaming/src/main/scala/spark/streaming/QueueInputDStream.scala
deleted file mode 100644
index bb86e51932..0000000000
--- a/streaming/src/main/scala/spark/streaming/QueueInputDStream.scala
+++ /dev/null
@@ -1,40 +0,0 @@
-package spark.streaming
-
-import spark.RDD
-import spark.rdd.UnionRDD
-
-import scala.collection.mutable.Queue
-import scala.collection.mutable.ArrayBuffer
-
-class QueueInputDStream[T: ClassManifest](
-    @transient ssc: StreamingContext,
-    val queue: Queue[RDD[T]],
-    oneAtATime: Boolean,
-    defaultRDD: RDD[T]
-  ) extends InputDStream[T](ssc) {
-  
-  override def start() { }
-  
-  override def stop() { }
-  
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    val buffer = new ArrayBuffer[RDD[T]]()
-    if (oneAtATime && queue.size > 0) {
-      buffer += queue.dequeue()
-    } else {
-      buffer ++= queue
-    }
-    if (buffer.size > 0) {
-      if (oneAtATime) {
-        Some(buffer.first)
-      } else {
-        Some(new UnionRDD(ssc.sc, buffer.toSeq))
-      }
-    } else if (defaultRDD != null) {
-      Some(defaultRDD)
-    } else {
-      None
-    }
-  }
-  
-}
diff --git a/streaming/src/main/scala/spark/streaming/RawInputDStream.scala b/streaming/src/main/scala/spark/streaming/RawInputDStream.scala
deleted file mode 100644
index 6acaa9aab1..0000000000
--- a/streaming/src/main/scala/spark/streaming/RawInputDStream.scala
+++ /dev/null
@@ -1,85 +0,0 @@
-package spark.streaming
-
-import java.net.InetSocketAddress
-import java.nio.ByteBuffer
-import java.nio.channels.{ReadableByteChannel, SocketChannel}
-import java.io.EOFException
-import java.util.concurrent.ArrayBlockingQueue
-import spark._
-import spark.storage.StorageLevel
-
-/**
- * An input stream that reads blocks of serialized objects from a given network address.
- * The blocks will be inserted directly into the block store. This is the fastest way to get
- * data into Spark Streaming, though it requires the sender to batch data and serialize it
- * in the format that the system is configured with.
- */
-class RawInputDStream[T: ClassManifest](
-    @transient ssc_ : StreamingContext,
-    host: String,
-    port: Int,
-    storageLevel: StorageLevel
-  ) extends NetworkInputDStream[T](ssc_ ) with Logging {
-
-  def createReceiver(): NetworkReceiver[T] = {
-    new RawNetworkReceiver(id, host, port, storageLevel).asInstanceOf[NetworkReceiver[T]]
-  }
-}
-
-class RawNetworkReceiver(streamId: Int, host: String, port: Int, storageLevel: StorageLevel)
-  extends NetworkReceiver[Any](streamId) {
-
-  var blockPushingThread: Thread = null
-
-  override def getLocationPreference = None
-
-  def onStart() {
-    // Open a socket to the target address and keep reading from it
-    logInfo("Connecting to " + host + ":" + port)
-    val channel = SocketChannel.open()
-    channel.configureBlocking(true)
-    channel.connect(new InetSocketAddress(host, port))
-    logInfo("Connected to " + host + ":" + port)
-
-    val queue = new ArrayBlockingQueue[ByteBuffer](2)
-
-    blockPushingThread = new DaemonThread {
-      override def run() {
-        var nextBlockNumber = 0
-        while (true) {
-          val buffer = queue.take()
-          val blockId = "input-" + streamId + "-" + nextBlockNumber
-          nextBlockNumber += 1
-          pushBlock(blockId, buffer, null, storageLevel)
-        }
-      }
-    }
-    blockPushingThread.start()
-
-    val lengthBuffer = ByteBuffer.allocate(4)
-    while (true) {
-      lengthBuffer.clear()
-      readFully(channel, lengthBuffer)
-      lengthBuffer.flip()
-      val length = lengthBuffer.getInt()
-      val dataBuffer = ByteBuffer.allocate(length)
-      readFully(channel, dataBuffer)
-      dataBuffer.flip()
-      logInfo("Read a block with " + length + " bytes")
-      queue.put(dataBuffer)
-    }
-  }
-
-  def onStop() {
-    if (blockPushingThread != null) blockPushingThread.interrupt()
-  }
-
-  /** Read a buffer fully from a given Channel */
-  private def readFully(channel: ReadableByteChannel, dest: ByteBuffer) {
-    while (dest.position < dest.limit) {
-      if (channel.read(dest) == -1) {
-        throw new EOFException("End of channel")
-      }
-    }
-  }
-}
diff --git a/streaming/src/main/scala/spark/streaming/ReducedWindowedDStream.scala b/streaming/src/main/scala/spark/streaming/ReducedWindowedDStream.scala
deleted file mode 100644
index f63a9e0011..0000000000
--- a/streaming/src/main/scala/spark/streaming/ReducedWindowedDStream.scala
+++ /dev/null
@@ -1,149 +0,0 @@
-package spark.streaming
-
-import spark.streaming.StreamingContext._
-
-import spark.RDD
-import spark.rdd.UnionRDD
-import spark.rdd.CoGroupedRDD
-import spark.Partitioner
-import spark.SparkContext._
-import spark.storage.StorageLevel
-
-import scala.collection.mutable.ArrayBuffer
-import collection.SeqProxy
-
-class ReducedWindowedDStream[K: ClassManifest, V: ClassManifest](
-    parent: DStream[(K, V)],
-    reduceFunc: (V, V) => V,
-    invReduceFunc: (V, V) => V, 
-    _windowTime: Time,
-    _slideTime: Time,
-    partitioner: Partitioner
-  ) extends DStream[(K,V)](parent.ssc) {
-
-  assert(_windowTime.isMultipleOf(parent.slideTime),
-    "The window duration of ReducedWindowedDStream (" + _slideTime + ") " +
-      "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")"
-  )
-
-  assert(_slideTime.isMultipleOf(parent.slideTime),
-    "The slide duration of ReducedWindowedDStream (" + _slideTime + ") " +
-      "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")"
-  )
-
-  // Reduce each batch of data using reduceByKey which will be further reduced by window 
-  // by ReducedWindowedDStream
-  val reducedStream = parent.reduceByKey(reduceFunc, partitioner)
-
-  // Persist RDDs to memory by default as these RDDs are going to be reused.
-  super.persist(StorageLevel.MEMORY_ONLY_SER)
-  reducedStream.persist(StorageLevel.MEMORY_ONLY_SER)
-
-  def windowTime: Time =  _windowTime
-
-  override def dependencies = List(reducedStream)
-
-  override def slideTime: Time = _slideTime
-
-  override val mustCheckpoint = true
-
-  override def parentRememberDuration: Time = rememberDuration + windowTime
-
-  override def persist(storageLevel: StorageLevel): DStream[(K,V)] = {
-    super.persist(storageLevel)
-    reducedStream.persist(storageLevel)
-    this
-  }
-
-  override def checkpoint(interval: Time): DStream[(K, V)] = {
-    super.checkpoint(interval)
-    //reducedStream.checkpoint(interval)
-    this
-  }
-
-  override def compute(validTime: Time): Option[RDD[(K, V)]] = {
-    val reduceF = reduceFunc
-    val invReduceF = invReduceFunc
-
-    val currentTime = validTime
-    val currentWindow = Interval(currentTime - windowTime + parent.slideTime, currentTime)
-    val previousWindow = currentWindow - slideTime
-
-    logDebug("Window time = " + windowTime)
-    logDebug("Slide time = " + slideTime)
-    logDebug("ZeroTime = " + zeroTime)
-    logDebug("Current window = " + currentWindow)
-    logDebug("Previous window = " + previousWindow)
-
-    //  _____________________________
-    // |  previous window   _________|___________________
-    // |___________________|       current window        |  --------------> Time
-    //                     |_____________________________|
-    //
-    // |________ _________|          |________ _________|
-    //          |                             |
-    //          V                             V
-    //       old RDDs                     new RDDs
-    //
-
-    // Get the RDDs of the reduced values in "old time steps"
-    val oldRDDs = reducedStream.slice(previousWindow.beginTime, currentWindow.beginTime - parent.slideTime)
-    logDebug("# old RDDs = " + oldRDDs.size)
-
-    // Get the RDDs of the reduced values in "new time steps"
-    val newRDDs = reducedStream.slice(previousWindow.endTime + parent.slideTime, currentWindow.endTime)
-    logDebug("# new RDDs = " + newRDDs.size)
-
-    // Get the RDD of the reduced value of the previous window
-    val previousWindowRDD = getOrCompute(previousWindow.endTime).getOrElse(ssc.sc.makeRDD(Seq[(K,V)]()))
-
-    // Make the list of RDDs that needs to cogrouped together for reducing their reduced values
-    val allRDDs = new ArrayBuffer[RDD[(K, V)]]() += previousWindowRDD ++= oldRDDs ++= newRDDs
-
-    // Cogroup the reduced RDDs and merge the reduced values
-    val cogroupedRDD = new CoGroupedRDD[K](allRDDs.toSeq.asInstanceOf[Seq[RDD[(_, _)]]], partitioner)
-    //val mergeValuesFunc = mergeValues(oldRDDs.size, newRDDs.size) _
-
-    val numOldValues = oldRDDs.size
-    val numNewValues = newRDDs.size
-
-    val mergeValues = (seqOfValues: Seq[Seq[V]]) => {
-      if (seqOfValues.size != 1 + numOldValues + numNewValues) {
-        throw new Exception("Unexpected number of sequences of reduced values")
-      }
-      // Getting reduced values "old time steps" that will be removed from current window
-      val oldValues = (1 to numOldValues).map(i => seqOfValues(i)).filter(!_.isEmpty).map(_.head)
-      // Getting reduced values "new time steps"
-      val newValues = (1 to numNewValues).map(i => seqOfValues(numOldValues + i)).filter(!_.isEmpty).map(_.head)
-      if (seqOfValues(0).isEmpty) {
-        // If previous window's reduce value does not exist, then at least new values should exist
-        if (newValues.isEmpty) {
-          throw new Exception("Neither previous window has value for key, nor new values found. " +
-            "Are you sure your key class hashes consistently?")
-        }
-        // Reduce the new values
-        newValues.reduce(reduceF) // return
-      } else {
-        // Get the previous window's reduced value
-        var tempValue = seqOfValues(0).head
-        // If old values exists, then inverse reduce then from previous value
-        if (!oldValues.isEmpty) {
-          tempValue = invReduceF(tempValue, oldValues.reduce(reduceF))
-        }
-        // If new values exists, then reduce them with previous value
-        if (!newValues.isEmpty) {
-          tempValue = reduceF(tempValue, newValues.reduce(reduceF))
-        }
-        tempValue // return
-      }
-    }
-
-    val mergedValuesRDD = cogroupedRDD.asInstanceOf[RDD[(K,Seq[Seq[V]])]].mapValues(mergeValues)
-
-    Some(mergedValuesRDD)
-  }
-
-
-}
-
-
diff --git a/streaming/src/main/scala/spark/streaming/Scheduler.scala b/streaming/src/main/scala/spark/streaming/Scheduler.scala
index fd1fa77a24..aeb7c3eb0e 100644
--- a/streaming/src/main/scala/spark/streaming/Scheduler.scala
+++ b/streaming/src/main/scala/spark/streaming/Scheduler.scala
@@ -4,9 +4,6 @@ import util.{ManualClock, RecurringTimer, Clock}
 import spark.SparkEnv
 import spark.Logging
 
-import scala.collection.mutable.HashMap
-
-
 private[streaming]
 class Scheduler(ssc: StreamingContext) extends Logging {
 
diff --git a/streaming/src/main/scala/spark/streaming/SocketInputDStream.scala b/streaming/src/main/scala/spark/streaming/SocketInputDStream.scala
deleted file mode 100644
index a9e37c0ff0..0000000000
--- a/streaming/src/main/scala/spark/streaming/SocketInputDStream.scala
+++ /dev/null
@@ -1,107 +0,0 @@
-package spark.streaming
-
-import spark.streaming.util.{RecurringTimer, SystemClock}
-import spark.storage.StorageLevel
-
-import java.io._
-import java.net.Socket
-import java.util.concurrent.ArrayBlockingQueue
-
-import scala.collection.mutable.ArrayBuffer
-import scala.Serializable
-
-class SocketInputDStream[T: ClassManifest](
-    @transient ssc_ : StreamingContext,
-    host: String,
-    port: Int,
-    bytesToObjects: InputStream => Iterator[T],
-    storageLevel: StorageLevel
-  ) extends NetworkInputDStream[T](ssc_) {
-
-  def createReceiver(): NetworkReceiver[T] = {
-    new SocketReceiver(id, host, port, bytesToObjects, storageLevel)
-  }
-}
-
-
-class SocketReceiver[T: ClassManifest](
-    streamId: Int,
-    host: String,
-    port: Int,
-    bytesToObjects: InputStream => Iterator[T],
-    storageLevel: StorageLevel
-  ) extends NetworkReceiver[T](streamId) {
-
-  lazy protected val dataHandler = new DataHandler(this, storageLevel)
-
-  override def getLocationPreference = None
-
-  protected def onStart() {
-    logInfo("Connecting to " + host + ":" + port)
-    val socket = new Socket(host, port)
-    logInfo("Connected to " + host + ":" + port)
-    dataHandler.start()
-    val iterator = bytesToObjects(socket.getInputStream())
-    while(iterator.hasNext) {
-      val obj = iterator.next
-      dataHandler += obj
-    }
-  }
-
-  protected def onStop() {
-    dataHandler.stop()
-  }
-
-}
-
-
-object SocketReceiver  {
-
-  /**
-   * This methods translates the data from an inputstream (say, from a socket)
-   * to '\n' delimited strings and returns an iterator to access the strings.
-   */
-  def bytesToLines(inputStream: InputStream): Iterator[String] = {
-    val dataInputStream = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"))
-
-    val iterator = new Iterator[String] {
-      var gotNext = false
-      var finished = false
-      var nextValue: String = null
-
-      private def getNext() {
-        try {
-          nextValue = dataInputStream.readLine()
-          if (nextValue == null) {
-            finished = true
-          }
-        }
-        gotNext = true
-      }
-
-      override def hasNext: Boolean = {
-        if (!finished) {
-          if (!gotNext) {
-            getNext()
-            if (finished) {
-              dataInputStream.close()
-            }
-          }
-        }
-        !finished
-      }
-
-      override def next(): String = {
-        if (finished) {
-          throw new NoSuchElementException("End of stream")
-        }
-        if (!gotNext) {
-          getNext()
-        }
-        gotNext = false
-        nextValue
-      }
-    }
-    iterator
-  }
-}
diff --git a/streaming/src/main/scala/spark/streaming/StateDStream.scala b/streaming/src/main/scala/spark/streaming/StateDStream.scala
deleted file mode 100644
index b7e4c1c30c..0000000000
--- a/streaming/src/main/scala/spark/streaming/StateDStream.scala
+++ /dev/null
@@ -1,84 +0,0 @@
-package spark.streaming
-
-import spark.RDD
-import spark.rdd.BlockRDD
-import spark.Partitioner
-import spark.rdd.MapPartitionsRDD
-import spark.SparkContext._
-import spark.storage.StorageLevel
-
-class StateDStream[K: ClassManifest, V: ClassManifest, S <: AnyRef : ClassManifest](
-    parent: DStream[(K, V)],
-    updateFunc: (Iterator[(K, Seq[V], Option[S])]) => Iterator[(K, S)],
-    partitioner: Partitioner,
-    preservePartitioning: Boolean
-  ) extends DStream[(K, S)](parent.ssc) {
-
-  super.persist(StorageLevel.MEMORY_ONLY_SER)
-
-  override def dependencies = List(parent)
-
-  override def slideTime = parent.slideTime
-
-  override val mustCheckpoint = true
-
-  override def compute(validTime: Time): Option[RDD[(K, S)]] = {
-
-    // Try to get the previous state RDD
-    getOrCompute(validTime - slideTime) match {
-
-      case Some(prevStateRDD) => {    // If previous state RDD exists
-
-        // Try to get the parent RDD
-        parent.getOrCompute(validTime) match {
-          case Some(parentRDD) => {   // If parent RDD exists, then compute as usual
-
-            // Define the function for the mapPartition operation on cogrouped RDD;
-            // first map the cogrouped tuple to tuples of required type,
-            // and then apply the update function
-            val updateFuncLocal = updateFunc
-            val finalFunc = (iterator: Iterator[(K, (Seq[V], Seq[S]))]) => {
-              val i = iterator.map(t => {
-                (t._1, t._2._1, t._2._2.headOption)
-              })
-              updateFuncLocal(i)
-            }
-            val cogroupedRDD = parentRDD.cogroup(prevStateRDD, partitioner)
-            val stateRDD = cogroupedRDD.mapPartitions(finalFunc, preservePartitioning)
-            //logDebug("Generating state RDD for time " + validTime)
-            return Some(stateRDD)
-          }
-          case None => {    // If parent RDD does not exist, then return old state RDD
-            return Some(prevStateRDD)
-          }
-        }
-      }
-
-      case None => {    // If previous session RDD does not exist (first input data)
-
-        // Try to get the parent RDD
-        parent.getOrCompute(validTime) match {
-          case Some(parentRDD) => {   // If parent RDD exists, then compute as usual
-
-            // Define the function for the mapPartition operation on grouped RDD;
-            // first map the grouped tuple to tuples of required type,
-            // and then apply the update function
-            val updateFuncLocal = updateFunc
-            val finalFunc = (iterator: Iterator[(K, Seq[V])]) => {
-              updateFuncLocal(iterator.map(tuple => (tuple._1, tuple._2, None)))
-            }
-
-            val groupedRDD = parentRDD.groupByKey(partitioner)
-            val sessionRDD = groupedRDD.mapPartitions(finalFunc, preservePartitioning)
-            //logDebug("Generating state RDD for time " + validTime + " (first)")
-            return Some(sessionRDD)
-          }
-          case None => { // If parent RDD does not exist, then nothing to do!
-            //logDebug("Not generating state RDD (no previous state, no parent)")
-            return None
-          }
-        }
-      }
-    }
-  }
-}
diff --git a/streaming/src/main/scala/spark/streaming/StreamingContext.scala b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
index 998fea849f..ef73049a81 100644
--- a/streaming/src/main/scala/spark/streaming/StreamingContext.scala
+++ b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
@@ -1,10 +1,10 @@
 package spark.streaming
 
-import spark.RDD
-import spark.Logging
-import spark.SparkEnv
-import spark.SparkContext
+import spark.streaming.dstream._
+
+import spark.{RDD, Logging, SparkEnv, SparkContext}
 import spark.storage.StorageLevel
+import spark.util.MetadataCleaner
 
 import scala.collection.mutable.Queue
 
@@ -18,7 +18,6 @@ import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
 import org.apache.flume.source.avro.AvroFlumeEvent
 import org.apache.hadoop.fs.Path
 import java.util.UUID
-import spark.util.MetadataCleaner
 
 /**
  * A StreamingContext is the main entry point for Spark Streaming functionality. Besides the basic
@@ -126,7 +125,7 @@ class StreamingContext private (
  /**
    * Create an input stream that pulls messages form a Kafka Broker.
    * 
-   * @param host Zookeper hostname.
+   * @param hostname Zookeper hostname.
    * @param port Zookeper port.
    * @param groupId The group id for this consumer.
    * @param topics Map of (topic_name -> numPartitions) to consume. Each partition is consumed
@@ -319,7 +318,7 @@ object StreamingContext {
 
   protected[streaming] def rddToFileName[T](prefix: String, suffix: String, time: Time): String = {
     if (prefix == null) {
-      time.millis.toString
+      time.milliseconds.toString
     } else if (suffix == null || suffix.length ==0) {
       prefix + "-" + time.milliseconds
     } else {
diff --git a/streaming/src/main/scala/spark/streaming/Time.scala b/streaming/src/main/scala/spark/streaming/Time.scala
index 480d292d7c..2976e5e87b 100644
--- a/streaming/src/main/scala/spark/streaming/Time.scala
+++ b/streaming/src/main/scala/spark/streaming/Time.scala
@@ -1,6 +1,11 @@
 package spark.streaming
 
-case class Time(millis: Long) {
+/**
+ * This class is simple wrapper class that represents time in UTC.
+ * @param millis Time in UTC long
+ */
+
+case class Time(private val millis: Long) {
   
   def < (that: Time): Boolean = (this.millis < that.millis)
  
@@ -15,7 +20,9 @@ case class Time(millis: Long) {
   def - (that: Time): Time = Time(millis - that.millis)
   
   def * (times: Int): Time = Time(millis * times)
-  
+
+  def / (that: Time): Long = millis / that.millis
+
   def floor(that: Time): Time = {
     val t = that.millis
     val m = math.floor(this.millis / t).toLong 
diff --git a/streaming/src/main/scala/spark/streaming/WindowedDStream.scala b/streaming/src/main/scala/spark/streaming/WindowedDStream.scala
deleted file mode 100644
index e4d2a634f5..0000000000
--- a/streaming/src/main/scala/spark/streaming/WindowedDStream.scala
+++ /dev/null
@@ -1,39 +0,0 @@
-package spark.streaming
-
-import spark.RDD
-import spark.rdd.UnionRDD
-import spark.storage.StorageLevel
-
-
-class WindowedDStream[T: ClassManifest](
-    parent: DStream[T],
-    _windowTime: Time,
-    _slideTime: Time) 
-  extends DStream[T](parent.ssc) {
-
-  if (!_windowTime.isMultipleOf(parent.slideTime))
-    throw new Exception("The window duration of WindowedDStream (" + _slideTime + ") " +
-    "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")")
-
-  if (!_slideTime.isMultipleOf(parent.slideTime))
-    throw new Exception("The slide duration of WindowedDStream (" + _slideTime + ") " +
-    "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")")
-
-  parent.persist(StorageLevel.MEMORY_ONLY_SER)
-
-  def windowTime: Time =  _windowTime
-
-  override def dependencies = List(parent)
-
-  override def slideTime: Time = _slideTime
-
-  override def parentRememberDuration: Time = rememberDuration + windowTime
-
-  override def compute(validTime: Time): Option[RDD[T]] = {
-    val currentWindow = Interval(validTime - windowTime + parent.slideTime, validTime)
-    Some(new UnionRDD(ssc.sc, parent.slice(currentWindow)))
-  }
-}
-
-
-
diff --git a/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
new file mode 100644
index 0000000000..2e427dadf7
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
@@ -0,0 +1,39 @@
+package spark.streaming.dstream
+
+import spark.{RDD, Partitioner}
+import spark.rdd.CoGroupedRDD
+import spark.streaming.{Time, DStream}
+
+class CoGroupedDStream[K : ClassManifest](
+    parents: Seq[DStream[(_, _)]],
+    partitioner: Partitioner
+  ) extends DStream[(K, Seq[Seq[_]])](parents.head.ssc) {
+
+  if (parents.length == 0) {
+    throw new IllegalArgumentException("Empty array of parents")
+  }
+
+  if (parents.map(_.ssc).distinct.size > 1) {
+    throw new IllegalArgumentException("Array of parents have different StreamingContexts")
+  }
+
+  if (parents.map(_.slideTime).distinct.size > 1) {
+    throw new IllegalArgumentException("Array of parents have different slide times")
+  }
+
+  override def dependencies = parents.toList
+
+  override def slideTime = parents.head.slideTime
+
+  override def compute(validTime: Time): Option[RDD[(K, Seq[Seq[_]])]] = {
+    val part = partitioner
+    val rdds = parents.flatMap(_.getOrCompute(validTime))
+    if (rdds.size > 0) {
+      val q = new CoGroupedRDD[K](rdds, part)
+      Some(q)
+    } else {
+      None
+    }
+  }
+
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/ConstantInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/ConstantInputDStream.scala
new file mode 100644
index 0000000000..41c3af4694
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/ConstantInputDStream.scala
@@ -0,0 +1,19 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.streaming.{Time, StreamingContext}
+
+/**
+ * An input stream that always returns the same RDD on each timestep. Useful for testing.
+ */
+class ConstantInputDStream[T: ClassManifest](ssc_ : StreamingContext, rdd: RDD[T])
+  extends InputDStream[T](ssc_) {
+
+  override def start() {}
+
+  override def stop() {}
+
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    Some(rdd)
+  }
+}
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/dstream/DataHandler.scala b/streaming/src/main/scala/spark/streaming/dstream/DataHandler.scala
new file mode 100644
index 0000000000..d737ba1ecc
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/DataHandler.scala
@@ -0,0 +1,83 @@
+package spark.streaming.dstream
+
+import java.util.concurrent.ArrayBlockingQueue
+import scala.collection.mutable.ArrayBuffer
+import spark.Logging
+import spark.streaming.util.{RecurringTimer, SystemClock}
+import spark.storage.StorageLevel
+
+
+/**
+   * This is a helper object that manages the data received from the socket. It divides
+   * the object received into small batches of 100s of milliseconds, pushes them as
+   * blocks into the block manager and reports the block IDs to the network input
+   * tracker. It starts two threads, one to periodically start a new batch and prepare
+   * the previous batch of as a block, the other to push the blocks into the block
+   * manager.
+   */
+  class DataHandler[T](receiver: NetworkReceiver[T], storageLevel: StorageLevel) 
+    extends Serializable with Logging {
+    
+    case class Block(id: String, iterator: Iterator[T], metadata: Any = null)
+
+    val clock = new SystemClock()
+    val blockInterval = 200L
+    val blockIntervalTimer = new RecurringTimer(clock, blockInterval, updateCurrentBuffer)
+    val blockStorageLevel = storageLevel
+    val blocksForPushing = new ArrayBlockingQueue[Block](1000)
+    val blockPushingThread = new Thread() { override def run() { keepPushingBlocks() } }
+
+    var currentBuffer = new ArrayBuffer[T]
+
+    def createBlock(blockId: String, iterator: Iterator[T]) : Block = {
+      new Block(blockId, iterator)
+    }
+
+    def start() {
+      blockIntervalTimer.start()
+      blockPushingThread.start()
+      logInfo("Data handler started")
+    }
+
+    def stop() {
+      blockIntervalTimer.stop()
+      blockPushingThread.interrupt()
+      logInfo("Data handler stopped")
+    }
+
+    def += (obj: T) {
+      currentBuffer += obj
+    }
+
+    def updateCurrentBuffer(time: Long) {
+      try {
+        val newBlockBuffer = currentBuffer
+        currentBuffer = new ArrayBuffer[T]
+        if (newBlockBuffer.size > 0) {
+          val blockId = "input-" + receiver.streamId + "- " + (time - blockInterval)
+          val newBlock = createBlock(blockId, newBlockBuffer.toIterator)
+          blocksForPushing.add(newBlock)
+        }
+      } catch {
+        case ie: InterruptedException =>
+          logInfo("Block interval timer thread interrupted")
+        case e: Exception =>
+          receiver.stop()
+      }
+    }
+
+    def keepPushingBlocks() {
+      logInfo("Block pushing thread started")
+      try {
+        while(true) {
+          val block = blocksForPushing.take()
+          receiver.pushBlock(block.id, block.iterator, block.metadata, storageLevel)
+        }
+      } catch {
+        case ie: InterruptedException =>
+          logInfo("Block pushing thread interrupted")
+        case e: Exception =>
+          receiver.stop()
+      }
+    }
+  }
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
new file mode 100644
index 0000000000..8cdaff467b
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
@@ -0,0 +1,110 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.rdd.UnionRDD
+import spark.streaming.{StreamingContext, Time}
+
+import org.apache.hadoop.fs.{FileSystem, Path, PathFilter}
+import org.apache.hadoop.conf.Configuration
+import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
+
+import scala.collection.mutable.HashSet
+
+
+class FileInputDStream[K: ClassManifest, V: ClassManifest, F <: NewInputFormat[K,V] : ClassManifest](
+    @transient ssc_ : StreamingContext,
+    directory: String,
+    filter: PathFilter = FileInputDStream.defaultPathFilter,
+    newFilesOnly: Boolean = true) 
+  extends InputDStream[(K, V)](ssc_) {
+
+  @transient private var path_ : Path = null
+  @transient private var fs_ : FileSystem = null
+
+  var lastModTime = 0L
+  val lastModTimeFiles = new HashSet[String]()
+
+  def path(): Path = {
+    if (path_ == null) path_ = new Path(directory)
+    path_
+  }
+
+  def fs(): FileSystem = {
+    if (fs_ == null) fs_ = path.getFileSystem(new Configuration())
+    fs_
+  }
+
+  override def start() {
+    if (newFilesOnly) {
+      lastModTime = System.currentTimeMillis()
+    } else {
+      lastModTime = 0
+    }
+  }
+  
+  override def stop() { }
+
+  /**
+   * Finds the files that were modified since the last time this method was called and makes
+   * a union RDD out of them. Note that this maintains the list of files that were processed
+   * in the latest modification time in the previous call to this method. This is because the
+   * modification time returned by the FileStatus API seems to return times only at the
+   * granularity of seconds. Hence, new files may have the same modification time as the
+   * latest modification time in the previous call to this method and the list of files
+   * maintained is used to filter the one that have been processed.
+   */
+  override def compute(validTime: Time): Option[RDD[(K, V)]] = {
+    // Create the filter for selecting new files
+    val newFilter = new PathFilter() {
+      var latestModTime = 0L
+      val latestModTimeFiles = new HashSet[String]()
+
+      def accept(path: Path): Boolean = {
+        if (!filter.accept(path)) {
+          return false
+        } else {
+          val modTime = fs.getFileStatus(path).getModificationTime()
+          if (modTime < lastModTime){
+            return false
+          } else if (modTime == lastModTime && lastModTimeFiles.contains(path.toString)) {
+            return false
+          }
+          if (modTime > latestModTime) {
+            latestModTime = modTime
+            latestModTimeFiles.clear()
+          }
+          latestModTimeFiles += path.toString
+          return true
+        }        
+      }
+    }
+
+    val newFiles = fs.listStatus(path, newFilter)
+    logInfo("New files: " + newFiles.map(_.getPath).mkString(", "))
+    if (newFiles.length > 0) {
+      // Update the modification time and the files processed for that modification time
+      if (lastModTime != newFilter.latestModTime) {
+        lastModTime = newFilter.latestModTime
+        lastModTimeFiles.clear()
+      }
+      lastModTimeFiles ++= newFilter.latestModTimeFiles
+    }
+    val newRDD = new UnionRDD(ssc.sc, newFiles.map(
+      file => ssc.sc.newAPIHadoopFile[K, V, F](file.getPath.toString)))
+    Some(newRDD)
+  }
+}
+
+object FileInputDStream {
+  val defaultPathFilter = new PathFilter with Serializable {
+    def accept(path: Path): Boolean = {
+      val file = path.getName()
+      if (file.startsWith(".") || file.endsWith("_tmp")) {
+        return false
+      } else {
+        return true
+      }
+    }
+  }
+}
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FilteredDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FilteredDStream.scala
new file mode 100644
index 0000000000..1cbb4d536e
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/FilteredDStream.scala
@@ -0,0 +1,21 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+
+private[streaming]
+class FilteredDStream[T: ClassManifest](
+    parent: DStream[T],
+    filterFunc: T => Boolean
+  ) extends DStream[T](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    parent.getOrCompute(validTime).map(_.filter(filterFunc))
+  }
+}
+
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FlatMapValuedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FlatMapValuedDStream.scala
new file mode 100644
index 0000000000..11ed8cf317
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/FlatMapValuedDStream.scala
@@ -0,0 +1,20 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+import spark.SparkContext._
+
+private[streaming]
+class FlatMapValuedDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
+    parent: DStream[(K, V)],
+    flatMapValueFunc: V => TraversableOnce[U]
+  ) extends DStream[(K, U)](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[(K, U)]] = {
+    parent.getOrCompute(validTime).map(_.flatMapValues[U](flatMapValueFunc))
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FlatMappedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FlatMappedDStream.scala
new file mode 100644
index 0000000000..a13b4c9ff9
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/FlatMappedDStream.scala
@@ -0,0 +1,20 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+
+private[streaming]
+class FlatMappedDStream[T: ClassManifest, U: ClassManifest](
+    parent: DStream[T],
+    flatMapFunc: T => Traversable[U]
+  ) extends DStream[U](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[U]] = {
+    parent.getOrCompute(validTime).map(_.flatMap(flatMapFunc))
+  }
+}
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
new file mode 100644
index 0000000000..7e988cadf4
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
@@ -0,0 +1,135 @@
+package spark.streaming.dstream
+
+import spark.streaming.StreamingContext
+
+import spark.Utils
+import spark.storage.StorageLevel
+
+import org.apache.flume.source.avro.AvroSourceProtocol
+import org.apache.flume.source.avro.AvroFlumeEvent
+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
+
+class FlumeInputDStream[T: ClassManifest](
+  @transient ssc_ : StreamingContext,
+  host: String,
+  port: Int,
+  storageLevel: StorageLevel
+) extends NetworkInputDStream[SparkFlumeEvent](ssc_) {
+
+  override def createReceiver(): NetworkReceiver[SparkFlumeEvent] = {
+    new FlumeReceiver(id, host, port, storageLevel)
+  }
+}
+
+/**
+ * A wrapper class for AvroFlumeEvent's with a custom serialization format.
+ *
+ * This is necessary because AvroFlumeEvent uses inner data structures
+ * which are not serializable.
+ */
+class SparkFlumeEvent() extends Externalizable {
+  var event : AvroFlumeEvent = new AvroFlumeEvent()
+
+  /* De-serialize from bytes. */
+  def readExternal(in: ObjectInput) {
+    val bodyLength = in.readInt()
+    val bodyBuff = new Array[Byte](bodyLength)
+    in.read(bodyBuff)
+
+    val numHeaders = in.readInt()
+    val headers = new java.util.HashMap[CharSequence, CharSequence]
+
+    for (i <- 0 until numHeaders) {
+      val keyLength = in.readInt()
+      val keyBuff = new Array[Byte](keyLength)
+      in.read(keyBuff)
+      val key : String = Utils.deserialize(keyBuff)
+
+      val valLength = in.readInt()
+      val valBuff = new Array[Byte](valLength)
+      in.read(valBuff)
+      val value : String = Utils.deserialize(valBuff)
+
+      headers.put(key, value)
+    }
+
+    event.setBody(ByteBuffer.wrap(bodyBuff))
+    event.setHeaders(headers)
+  }
+
+  /* Serialize to bytes. */
+  def writeExternal(out: ObjectOutput) {
+    val body = event.getBody.array()
+    out.writeInt(body.length)
+    out.write(body)
+
+    val numHeaders = event.getHeaders.size()
+    out.writeInt(numHeaders)
+    for ((k, v) <- event.getHeaders) {
+      val keyBuff = Utils.serialize(k.toString)
+      out.writeInt(keyBuff.length)
+      out.write(keyBuff)
+      val valBuff = Utils.serialize(v.toString)
+      out.writeInt(valBuff.length)
+      out.write(valBuff)
+    }
+  }
+}
+
+private[streaming] object SparkFlumeEvent {
+  def fromAvroFlumeEvent(in : AvroFlumeEvent) : SparkFlumeEvent = {
+    val event = new SparkFlumeEvent
+    event.event = in
+    event
+  }
+}
+
+/** A simple server that implements Flume's Avro protocol. */
+class FlumeEventServer(receiver : FlumeReceiver) extends AvroSourceProtocol {
+  override def append(event : AvroFlumeEvent) : Status = {
+    receiver.dataHandler += SparkFlumeEvent.fromAvroFlumeEvent(event)
+    Status.OK
+  }
+
+  override def appendBatch(events : java.util.List[AvroFlumeEvent]) : Status = {
+    events.foreach (event =>
+      receiver.dataHandler += SparkFlumeEvent.fromAvroFlumeEvent(event))
+    Status.OK
+  }
+}
+
+/** A NetworkReceiver which listens for events using the
+  * Flume Avro interface.*/
+class FlumeReceiver(
+      streamId: Int,
+      host: String,
+      port: Int,
+      storageLevel: StorageLevel
+      ) extends NetworkReceiver[SparkFlumeEvent](streamId) {
+
+  lazy val dataHandler = new DataHandler(this, storageLevel)
+
+  protected override def onStart() {
+    val responder = new SpecificResponder(
+      classOf[AvroSourceProtocol], new FlumeEventServer(this));
+    val server = new NettyServer(responder, new InetSocketAddress(host, port));
+    dataHandler.start()
+    server.start()
+    logInfo("Flume receiver started")
+  }
+
+  protected override def onStop() {
+    dataHandler.stop()
+    logInfo("Flume receiver stopped")
+  }
+
+  override def getLocationPreference = Some(host)
+}
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/dstream/ForEachDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/ForEachDStream.scala
new file mode 100644
index 0000000000..41c629a225
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/ForEachDStream.scala
@@ -0,0 +1,28 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.streaming.{DStream, Job, Time}
+
+private[streaming]
+class ForEachDStream[T: ClassManifest] (
+    parent: DStream[T],
+    foreachFunc: (RDD[T], Time) => Unit
+  ) extends DStream[Unit](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[Unit]] = None
+
+  override def generateJob(time: Time): Option[Job] = {
+    parent.getOrCompute(time) match {
+      case Some(rdd) =>
+        val jobFunc = () => {
+          foreachFunc(rdd, time)
+        }
+        Some(new Job(time, jobFunc))
+      case None => None
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/GlommedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/GlommedDStream.scala
new file mode 100644
index 0000000000..92ea503cae
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/GlommedDStream.scala
@@ -0,0 +1,17 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+
+private[streaming]
+class GlommedDStream[T: ClassManifest](parent: DStream[T])
+  extends DStream[Array[T]](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[Array[T]]] = {
+    parent.getOrCompute(validTime).map(_.glom())
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/InputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/InputDStream.scala
new file mode 100644
index 0000000000..4959c66b06
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/InputDStream.scala
@@ -0,0 +1,19 @@
+package spark.streaming.dstream
+
+import spark.streaming.{StreamingContext, DStream}
+
+abstract class InputDStream[T: ClassManifest] (@transient ssc_ : StreamingContext)
+  extends DStream[T](ssc_) {
+
+  override def dependencies = List()
+
+  override def slideTime = {
+    if (ssc == null) throw new Exception("ssc is null")
+    if (ssc.graph.batchDuration == null) throw new Exception("batchDuration is null")
+    ssc.graph.batchDuration
+  }
+
+  def start()
+
+  def stop()
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
new file mode 100644
index 0000000000..a46721af2f
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
@@ -0,0 +1,197 @@
+package spark.streaming.dstream
+
+import spark.Logging
+import spark.storage.StorageLevel
+import spark.streaming.{Time, DStreamCheckpointData, StreamingContext}
+
+import java.util.Properties
+import java.util.concurrent.Executors
+
+import kafka.consumer._
+import kafka.message.{Message, MessageSet, MessageAndMetadata}
+import kafka.serializer.StringDecoder
+import kafka.utils.{Utils, ZKGroupTopicDirs}
+import kafka.utils.ZkUtils._
+
+import scala.collection.mutable.HashMap
+import scala.collection.JavaConversions._
+
+
+// Key for a specific Kafka Partition: (broker, topic, group, part)
+case class KafkaPartitionKey(brokerId: Int, topic: String, groupId: String, partId: Int)
+// NOT USED - Originally intended for fault-tolerance
+// Metadata for a Kafka Stream that it sent to the Master
+case class KafkaInputDStreamMetadata(timestamp: Long, data: Map[KafkaPartitionKey, Long])
+// NOT USED - Originally intended for fault-tolerance
+// Checkpoint data specific to a KafkaInputDstream
+case class KafkaDStreamCheckpointData(kafkaRdds: HashMap[Time, Any], 
+  savedOffsets: Map[KafkaPartitionKey, Long]) extends DStreamCheckpointData(kafkaRdds)
+
+/**
+ * Input stream that pulls messages from a Kafka Broker.
+ * 
+ * @param host Zookeper hostname.
+ * @param port Zookeper port.
+ * @param groupId The group id for this consumer.
+ * @param topics Map of (topic_name -> numPartitions) to consume. Each partition is consumed
+ * in its own thread.
+ * @param initialOffsets Optional initial offsets for each of the partitions to consume.
+ * By default the value is pulled from zookeper.
+ * @param storageLevel RDD storage level.
+ */
+class KafkaInputDStream[T: ClassManifest](
+    @transient ssc_ : StreamingContext,
+    host: String,
+    port: Int,
+    groupId: String,
+    topics: Map[String, Int],
+    initialOffsets: Map[KafkaPartitionKey, Long],
+    storageLevel: StorageLevel
+  ) extends NetworkInputDStream[T](ssc_ ) with Logging {
+
+  // Metadata that keeps track of which messages have already been consumed.
+  var savedOffsets = HashMap[Long, Map[KafkaPartitionKey, Long]]()
+  
+  /* NOT USED - Originally intended for fault-tolerance
+ 
+  // In case of a failure, the offets for a particular timestamp will be restored.
+  @transient var restoredOffsets : Map[KafkaPartitionKey, Long] = null
+
+ 
+  override protected[streaming] def addMetadata(metadata: Any) {
+    metadata match {
+      case x : KafkaInputDStreamMetadata =>
+        savedOffsets(x.timestamp) = x.data
+        // TOOD: Remove logging
+        logInfo("New saved Offsets: " + savedOffsets)
+      case _ => logInfo("Received unknown metadata: " + metadata.toString)
+    }
+  }
+
+  override protected[streaming] def updateCheckpointData(currentTime: Time) {
+    super.updateCheckpointData(currentTime)
+    if(savedOffsets.size > 0) {
+      // Find the offets that were stored before the checkpoint was initiated
+      val key = savedOffsets.keys.toList.sortWith(_ < _).filter(_ < currentTime.millis).last
+      val latestOffsets = savedOffsets(key)
+      logInfo("Updating KafkaDStream checkpoint data: " + latestOffsets.toString)
+      checkpointData = KafkaDStreamCheckpointData(checkpointData.rdds, latestOffsets)
+      // TODO: This may throw out offsets that are created after the checkpoint,
+      // but it's unlikely we'll need them.
+      savedOffsets.clear()
+    }
+  }
+
+  override protected[streaming] def restoreCheckpointData() {
+    super.restoreCheckpointData()
+    logInfo("Restoring KafkaDStream checkpoint data.")
+    checkpointData match { 
+      case x : KafkaDStreamCheckpointData => 
+        restoredOffsets = x.savedOffsets
+        logInfo("Restored KafkaDStream offsets: " + savedOffsets)
+    }
+  } */
+
+  def createReceiver(): NetworkReceiver[T] = {
+    new KafkaReceiver(id, host, port,  groupId, topics, initialOffsets, storageLevel)
+        .asInstanceOf[NetworkReceiver[T]]
+  }
+}
+
+class KafkaReceiver(streamId: Int, host: String, port: Int, groupId: String, 
+  topics: Map[String, Int], initialOffsets: Map[KafkaPartitionKey, Long], 
+  storageLevel: StorageLevel) extends NetworkReceiver[Any](streamId) {
+
+  // Timeout for establishing a connection to Zookeper in ms.
+  val ZK_TIMEOUT = 10000
+
+  // Handles pushing data into the BlockManager
+  lazy protected val dataHandler = new DataHandler(this, storageLevel)
+  // Keeps track of the current offsets. Maps from (broker, topic, group, part) -> Offset
+  lazy val offsets = HashMap[KafkaPartitionKey, Long]()
+  // Connection to Kafka
+  var consumerConnector : ZookeeperConsumerConnector = null
+
+  def onStop() {
+    dataHandler.stop()
+  }
+
+  def onStart() {
+
+    // Starting the DataHandler that buffers blocks and pushes them into them BlockManager
+    dataHandler.start()
+
+    // In case we are using multiple Threads to handle Kafka Messages
+    val executorPool = Executors.newFixedThreadPool(topics.values.reduce(_ + _))
+
+    val zooKeeperEndPoint = host + ":" + port
+    logInfo("Starting Kafka Consumer Stream with group: " + groupId)
+    logInfo("Initial offsets: " + initialOffsets.toString)
+    
+    // Zookeper connection properties
+    val props = new Properties()
+    props.put("zk.connect", zooKeeperEndPoint)
+    props.put("zk.connectiontimeout.ms", ZK_TIMEOUT.toString)
+    props.put("groupid", groupId)
+
+    // Create the connection to the cluster
+    logInfo("Connecting to Zookeper: " + zooKeeperEndPoint)
+    val consumerConfig = new ConsumerConfig(props)
+    consumerConnector = Consumer.create(consumerConfig).asInstanceOf[ZookeeperConsumerConnector]
+    logInfo("Connected to " + zooKeeperEndPoint)
+
+    // Reset the Kafka offsets in case we are recovering from a failure
+    resetOffsets(initialOffsets)
+
+    // Create Threads for each Topic/Message Stream we are listening
+    val topicMessageStreams = consumerConnector.createMessageStreams(topics, new StringDecoder())
+
+    // Start the messages handler for each partition
+    topicMessageStreams.values.foreach { streams =>
+      streams.foreach { stream => executorPool.submit(new MessageHandler(stream)) }
+    }
+
+  }
+
+  // Overwrites the offets in Zookeper.
+  private def resetOffsets(offsets: Map[KafkaPartitionKey, Long]) {
+    offsets.foreach { case(key, offset) =>
+      val topicDirs = new ZKGroupTopicDirs(key.groupId, key.topic)
+      val partitionName = key.brokerId + "-" + key.partId
+      updatePersistentPath(consumerConnector.zkClient, 
+        topicDirs.consumerOffsetDir + "/" + partitionName, offset.toString)
+    }
+  }
+
+  // Handles Kafka Messages
+  private class MessageHandler(stream: KafkaStream[String]) extends Runnable {
+    def run() {
+      logInfo("Starting MessageHandler.")
+      stream.takeWhile { msgAndMetadata => 
+        dataHandler += msgAndMetadata.message
+
+        // Updating the offet. The key is (broker, topic, group, partition).
+        val key = KafkaPartitionKey(msgAndMetadata.topicInfo.brokerId, msgAndMetadata.topic, 
+          groupId, msgAndMetadata.topicInfo.partition.partId)
+        val offset = msgAndMetadata.topicInfo.getConsumeOffset
+        offsets.put(key, offset)
+        // logInfo("Handled message: " + (key, offset).toString)
+
+        // Keep on handling messages
+        true
+      }  
+    }
+  }
+
+  // NOT USED - Originally intended for fault-tolerance
+  // class KafkaDataHandler(receiver: KafkaReceiver, storageLevel: StorageLevel) 
+  // extends DataHandler[Any](receiver, storageLevel) {
+
+  //   override def createBlock(blockId: String, iterator: Iterator[Any]) : Block = {
+  //     // Creates a new Block with Kafka-specific Metadata
+  //     new Block(blockId, iterator, KafkaInputDStreamMetadata(System.currentTimeMillis, offsets.toMap))
+  //   }
+
+  // }
+
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/MapPartitionedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/MapPartitionedDStream.scala
new file mode 100644
index 0000000000..daf78c6893
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/MapPartitionedDStream.scala
@@ -0,0 +1,21 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+
+private[streaming]
+class MapPartitionedDStream[T: ClassManifest, U: ClassManifest](
+    parent: DStream[T],
+    mapPartFunc: Iterator[T] => Iterator[U],
+    preservePartitioning: Boolean
+  ) extends DStream[U](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[U]] = {
+    parent.getOrCompute(validTime).map(_.mapPartitions[U](mapPartFunc, preservePartitioning))
+  }
+}
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/MapValuedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/MapValuedDStream.scala
new file mode 100644
index 0000000000..689caeef0e
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/MapValuedDStream.scala
@@ -0,0 +1,21 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+import spark.SparkContext._
+
+private[streaming]
+class MapValuedDStream[K: ClassManifest, V: ClassManifest, U: ClassManifest](
+    parent: DStream[(K, V)],
+    mapValueFunc: V => U
+  ) extends DStream[(K, U)](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[(K, U)]] = {
+    parent.getOrCompute(validTime).map(_.mapValues[U](mapValueFunc))
+  }
+}
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/MappedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/MappedDStream.scala
new file mode 100644
index 0000000000..786b9966f2
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/MappedDStream.scala
@@ -0,0 +1,20 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+
+private[streaming]
+class MappedDStream[T: ClassManifest, U: ClassManifest] (
+    parent: DStream[T],
+    mapFunc: T => U
+  ) extends DStream[U](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[U]] = {
+    parent.getOrCompute(validTime).map(_.map[U](mapFunc))
+  }
+}
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/NetworkInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/NetworkInputDStream.scala
new file mode 100644
index 0000000000..41276da8bb
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/NetworkInputDStream.scala
@@ -0,0 +1,157 @@
+package spark.streaming.dstream
+
+import spark.streaming.{Time, StreamingContext, AddBlocks, RegisterReceiver, DeregisterReceiver}
+
+import spark.{Logging, SparkEnv, RDD}
+import spark.rdd.BlockRDD
+import spark.storage.StorageLevel
+
+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._
+
+abstract class NetworkInputDStream[T: ClassManifest](@transient ssc_ : StreamingContext)
+  extends InputDStream[T](ssc_) {
+
+  // This is an unique identifier that is used to match the network receiver with the
+  // corresponding network input stream.
+  val id = ssc.getNewNetworkStreamId()
+
+  /**
+   * This method creates the receiver object that will be sent to the workers
+   * to receive data. This method needs to defined by any specific implementation
+   * of a NetworkInputDStream.
+   */
+  def createReceiver(): NetworkReceiver[T]
+
+  // Nothing to start or stop as both taken care of by the NetworkInputTracker.
+  def start() {}
+
+  def stop() {}
+
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    val blockIds = ssc.networkInputTracker.getBlockIds(id, validTime)    
+    Some(new BlockRDD[T](ssc.sc, blockIds))
+  }
+}
+
+
+private[streaming] sealed trait NetworkReceiverMessage
+private[streaming] case class StopReceiver(msg: String) extends NetworkReceiverMessage
+private[streaming] case class ReportBlock(blockId: String, metadata: Any) extends NetworkReceiverMessage
+private[streaming] case class ReportError(msg: String) extends NetworkReceiverMessage
+
+abstract class NetworkReceiver[T: ClassManifest](val streamId: Int) extends Serializable with Logging {
+
+  initLogging()
+
+  lazy protected val env = SparkEnv.get
+
+  lazy protected val actor = env.actorSystem.actorOf(
+    Props(new NetworkReceiverActor()), "NetworkReceiver-" + streamId)
+
+  lazy protected val receivingThread = Thread.currentThread()
+
+  /** This method will be called to start receiving data. */
+  protected def onStart()
+
+  /** This method will be called to stop receiving data. */
+  protected def onStop()
+
+  /** This method conveys a placement preference (hostname) for this receiver. */
+  def getLocationPreference() : Option[String] = None
+
+  /**
+   * This method starts the receiver. First is accesses all the lazy members to
+   * materialize them. Then it calls the user-defined onStart() method to start
+   * other threads, etc required to receiver the data.
+   */
+  def start() {
+    try {
+      // Access the lazy vals to materialize them
+      env
+      actor
+      receivingThread
+
+      // Call user-defined onStart()
+      onStart()
+    } catch {
+      case ie: InterruptedException =>
+        logInfo("Receiving thread interrupted")
+        //println("Receiving thread interrupted")
+      case e: Exception =>
+        stopOnError(e)
+    }
+  }
+
+  /**
+   * This method stops the receiver. First it interrupts the main receiving thread,
+   * that is, the thread that called receiver.start(). Then it calls the user-defined
+   * onStop() method to stop other threads and/or do cleanup.
+   */
+  def stop() {
+    receivingThread.interrupt()
+    onStop()
+    //TODO: terminate the actor
+  }
+
+  /**
+   * This method stops the receiver and reports to exception to the tracker.
+   * This should be called whenever an exception has happened on any thread
+   * of the receiver.
+   */
+  protected def stopOnError(e: Exception) {
+    logError("Error receiving data", e)
+    stop()
+    actor ! ReportError(e.toString)
+  }
+
+
+  /**
+   * This method pushes a block (as iterator of values) into the block manager.
+   */
+  def pushBlock(blockId: String, iterator: Iterator[T], metadata: Any, level: StorageLevel) {
+    val buffer = new ArrayBuffer[T] ++ iterator
+    env.blockManager.put(blockId, buffer.asInstanceOf[ArrayBuffer[Any]], level)
+
+    actor ! ReportBlock(blockId, metadata)
+  }
+
+  /**
+   * This method pushes a block (as bytes) into the block manager.
+   */
+  def pushBlock(blockId: String, bytes: ByteBuffer, metadata: Any, level: StorageLevel) {
+    env.blockManager.putBytes(blockId, bytes, level)
+    actor ! ReportBlock(blockId, metadata)
+  }
+
+  /** A helper actor that communicates with the NetworkInputTracker */
+  private class NetworkReceiverActor extends Actor {
+    logInfo("Attempting to register with tracker")
+    val ip = System.getProperty("spark.master.host", "localhost")
+    val port = System.getProperty("spark.master.port", "7077").toInt
+    val url = "akka://spark@%s:%s/user/NetworkInputTracker".format(ip, port)
+    val tracker = env.actorSystem.actorFor(url)
+    val timeout = 5.seconds
+
+    override def preStart() {
+      val future = tracker.ask(RegisterReceiver(streamId, self))(timeout)
+      Await.result(future, timeout)
+    }
+
+    override def receive() = {
+      case ReportBlock(blockId, metadata) =>
+        tracker ! AddBlocks(streamId, Array(blockId), metadata)
+      case ReportError(msg) =>
+        tracker ! DeregisterReceiver(streamId, msg)
+      case StopReceiver(msg) =>
+        stop()
+        tracker ! DeregisterReceiver(streamId, msg)
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/QueueInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/QueueInputDStream.scala
new file mode 100644
index 0000000000..024bf3bea4
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/QueueInputDStream.scala
@@ -0,0 +1,41 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.rdd.UnionRDD
+
+import scala.collection.mutable.Queue
+import scala.collection.mutable.ArrayBuffer
+import spark.streaming.{Time, StreamingContext}
+
+class QueueInputDStream[T: ClassManifest](
+    @transient ssc: StreamingContext,
+    val queue: Queue[RDD[T]],
+    oneAtATime: Boolean,
+    defaultRDD: RDD[T]
+  ) extends InputDStream[T](ssc) {
+  
+  override def start() { }
+  
+  override def stop() { }
+  
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    val buffer = new ArrayBuffer[RDD[T]]()
+    if (oneAtATime && queue.size > 0) {
+      buffer += queue.dequeue()
+    } else {
+      buffer ++= queue
+    }
+    if (buffer.size > 0) {
+      if (oneAtATime) {
+        Some(buffer.first)
+      } else {
+        Some(new UnionRDD(ssc.sc, buffer.toSeq))
+      }
+    } else if (defaultRDD != null) {
+      Some(defaultRDD)
+    } else {
+      None
+    }
+  }
+  
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
new file mode 100644
index 0000000000..996cc7dea8
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
@@ -0,0 +1,88 @@
+package spark.streaming.dstream
+
+import spark.{DaemonThread, Logging}
+import spark.storage.StorageLevel
+import spark.streaming.StreamingContext
+
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+import java.nio.channels.{ReadableByteChannel, SocketChannel}
+import java.io.EOFException
+import java.util.concurrent.ArrayBlockingQueue
+
+
+/**
+ * An input stream that reads blocks of serialized objects from a given network address.
+ * The blocks will be inserted directly into the block store. This is the fastest way to get
+ * data into Spark Streaming, though it requires the sender to batch data and serialize it
+ * in the format that the system is configured with.
+ */
+class RawInputDStream[T: ClassManifest](
+    @transient ssc_ : StreamingContext,
+    host: String,
+    port: Int,
+    storageLevel: StorageLevel
+  ) extends NetworkInputDStream[T](ssc_ ) with Logging {
+
+  def createReceiver(): NetworkReceiver[T] = {
+    new RawNetworkReceiver(id, host, port, storageLevel).asInstanceOf[NetworkReceiver[T]]
+  }
+}
+
+class RawNetworkReceiver(streamId: Int, host: String, port: Int, storageLevel: StorageLevel)
+  extends NetworkReceiver[Any](streamId) {
+
+  var blockPushingThread: Thread = null
+
+  override def getLocationPreference = None
+
+  def onStart() {
+    // Open a socket to the target address and keep reading from it
+    logInfo("Connecting to " + host + ":" + port)
+    val channel = SocketChannel.open()
+    channel.configureBlocking(true)
+    channel.connect(new InetSocketAddress(host, port))
+    logInfo("Connected to " + host + ":" + port)
+
+    val queue = new ArrayBlockingQueue[ByteBuffer](2)
+
+    blockPushingThread = new DaemonThread {
+      override def run() {
+        var nextBlockNumber = 0
+        while (true) {
+          val buffer = queue.take()
+          val blockId = "input-" + streamId + "-" + nextBlockNumber
+          nextBlockNumber += 1
+          pushBlock(blockId, buffer, null, storageLevel)
+        }
+      }
+    }
+    blockPushingThread.start()
+
+    val lengthBuffer = ByteBuffer.allocate(4)
+    while (true) {
+      lengthBuffer.clear()
+      readFully(channel, lengthBuffer)
+      lengthBuffer.flip()
+      val length = lengthBuffer.getInt()
+      val dataBuffer = ByteBuffer.allocate(length)
+      readFully(channel, dataBuffer)
+      dataBuffer.flip()
+      logInfo("Read a block with " + length + " bytes")
+      queue.put(dataBuffer)
+    }
+  }
+
+  def onStop() {
+    if (blockPushingThread != null) blockPushingThread.interrupt()
+  }
+
+  /** Read a buffer fully from a given Channel */
+  private def readFully(channel: ReadableByteChannel, dest: ByteBuffer) {
+    while (dest.position < dest.limit) {
+      if (channel.read(dest) == -1) {
+        throw new EOFException("End of channel")
+      }
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
new file mode 100644
index 0000000000..2686de14d2
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
@@ -0,0 +1,148 @@
+package spark.streaming.dstream
+
+import spark.streaming.StreamingContext._
+
+import spark.RDD
+import spark.rdd.CoGroupedRDD
+import spark.Partitioner
+import spark.SparkContext._
+import spark.storage.StorageLevel
+
+import scala.collection.mutable.ArrayBuffer
+import spark.streaming.{Interval, Time, DStream}
+
+class ReducedWindowedDStream[K: ClassManifest, V: ClassManifest](
+    parent: DStream[(K, V)],
+    reduceFunc: (V, V) => V,
+    invReduceFunc: (V, V) => V, 
+    _windowTime: Time,
+    _slideTime: Time,
+    partitioner: Partitioner
+  ) extends DStream[(K,V)](parent.ssc) {
+
+  assert(_windowTime.isMultipleOf(parent.slideTime),
+    "The window duration of ReducedWindowedDStream (" + _slideTime + ") " +
+      "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")"
+  )
+
+  assert(_slideTime.isMultipleOf(parent.slideTime),
+    "The slide duration of ReducedWindowedDStream (" + _slideTime + ") " +
+      "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")"
+  )
+
+  // Reduce each batch of data using reduceByKey which will be further reduced by window 
+  // by ReducedWindowedDStream
+  val reducedStream = parent.reduceByKey(reduceFunc, partitioner)
+
+  // Persist RDDs to memory by default as these RDDs are going to be reused.
+  super.persist(StorageLevel.MEMORY_ONLY_SER)
+  reducedStream.persist(StorageLevel.MEMORY_ONLY_SER)
+
+  def windowTime: Time =  _windowTime
+
+  override def dependencies = List(reducedStream)
+
+  override def slideTime: Time = _slideTime
+
+  override val mustCheckpoint = true
+
+  override def parentRememberDuration: Time = rememberDuration + windowTime
+
+  override def persist(storageLevel: StorageLevel): DStream[(K,V)] = {
+    super.persist(storageLevel)
+    reducedStream.persist(storageLevel)
+    this
+  }
+
+  override def checkpoint(interval: Time): DStream[(K, V)] = {
+    super.checkpoint(interval)
+    //reducedStream.checkpoint(interval)
+    this
+  }
+
+  override def compute(validTime: Time): Option[RDD[(K, V)]] = {
+    val reduceF = reduceFunc
+    val invReduceF = invReduceFunc
+
+    val currentTime = validTime
+    val currentWindow = Interval(currentTime - windowTime + parent.slideTime, currentTime)
+    val previousWindow = currentWindow - slideTime
+
+    logDebug("Window time = " + windowTime)
+    logDebug("Slide time = " + slideTime)
+    logDebug("ZeroTime = " + zeroTime)
+    logDebug("Current window = " + currentWindow)
+    logDebug("Previous window = " + previousWindow)
+
+    //  _____________________________
+    // |  previous window   _________|___________________
+    // |___________________|       current window        |  --------------> Time
+    //                     |_____________________________|
+    //
+    // |________ _________|          |________ _________|
+    //          |                             |
+    //          V                             V
+    //       old RDDs                     new RDDs
+    //
+
+    // Get the RDDs of the reduced values in "old time steps"
+    val oldRDDs = reducedStream.slice(previousWindow.beginTime, currentWindow.beginTime - parent.slideTime)
+    logDebug("# old RDDs = " + oldRDDs.size)
+
+    // Get the RDDs of the reduced values in "new time steps"
+    val newRDDs = reducedStream.slice(previousWindow.endTime + parent.slideTime, currentWindow.endTime)
+    logDebug("# new RDDs = " + newRDDs.size)
+
+    // Get the RDD of the reduced value of the previous window
+    val previousWindowRDD = getOrCompute(previousWindow.endTime).getOrElse(ssc.sc.makeRDD(Seq[(K,V)]()))
+
+    // Make the list of RDDs that needs to cogrouped together for reducing their reduced values
+    val allRDDs = new ArrayBuffer[RDD[(K, V)]]() += previousWindowRDD ++= oldRDDs ++= newRDDs
+
+    // Cogroup the reduced RDDs and merge the reduced values
+    val cogroupedRDD = new CoGroupedRDD[K](allRDDs.toSeq.asInstanceOf[Seq[RDD[(_, _)]]], partitioner)
+    //val mergeValuesFunc = mergeValues(oldRDDs.size, newRDDs.size) _
+
+    val numOldValues = oldRDDs.size
+    val numNewValues = newRDDs.size
+
+    val mergeValues = (seqOfValues: Seq[Seq[V]]) => {
+      if (seqOfValues.size != 1 + numOldValues + numNewValues) {
+        throw new Exception("Unexpected number of sequences of reduced values")
+      }
+      // Getting reduced values "old time steps" that will be removed from current window
+      val oldValues = (1 to numOldValues).map(i => seqOfValues(i)).filter(!_.isEmpty).map(_.head)
+      // Getting reduced values "new time steps"
+      val newValues = (1 to numNewValues).map(i => seqOfValues(numOldValues + i)).filter(!_.isEmpty).map(_.head)
+      if (seqOfValues(0).isEmpty) {
+        // If previous window's reduce value does not exist, then at least new values should exist
+        if (newValues.isEmpty) {
+          throw new Exception("Neither previous window has value for key, nor new values found. " +
+            "Are you sure your key class hashes consistently?")
+        }
+        // Reduce the new values
+        newValues.reduce(reduceF) // return
+      } else {
+        // Get the previous window's reduced value
+        var tempValue = seqOfValues(0).head
+        // If old values exists, then inverse reduce then from previous value
+        if (!oldValues.isEmpty) {
+          tempValue = invReduceF(tempValue, oldValues.reduce(reduceF))
+        }
+        // If new values exists, then reduce them with previous value
+        if (!newValues.isEmpty) {
+          tempValue = reduceF(tempValue, newValues.reduce(reduceF))
+        }
+        tempValue // return
+      }
+    }
+
+    val mergedValuesRDD = cogroupedRDD.asInstanceOf[RDD[(K,Seq[Seq[V]])]].mapValues(mergeValues)
+
+    Some(mergedValuesRDD)
+  }
+
+
+}
+
+
diff --git a/streaming/src/main/scala/spark/streaming/dstream/ShuffledDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/ShuffledDStream.scala
new file mode 100644
index 0000000000..6854bbe665
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/ShuffledDStream.scala
@@ -0,0 +1,27 @@
+package spark.streaming.dstream
+
+import spark.{RDD, Partitioner}
+import spark.SparkContext._
+import spark.streaming.{DStream, Time}
+
+private[streaming]
+class ShuffledDStream[K: ClassManifest, V: ClassManifest, C: ClassManifest](
+    parent: DStream[(K,V)],
+    createCombiner: V => C,
+    mergeValue: (C, V) => C,
+    mergeCombiner: (C, C) => C,
+    partitioner: Partitioner
+  ) extends DStream [(K,C)] (parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[(K,C)]] = {
+    parent.getOrCompute(validTime) match {
+      case Some(rdd) =>
+        Some(rdd.combineByKey[C](createCombiner, mergeValue, mergeCombiner, partitioner))
+      case None => None
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
new file mode 100644
index 0000000000..af5b73ae8d
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
@@ -0,0 +1,103 @@
+package spark.streaming.dstream
+
+import spark.streaming.StreamingContext
+import spark.storage.StorageLevel
+
+import java.io._
+import java.net.Socket
+
+class SocketInputDStream[T: ClassManifest](
+    @transient ssc_ : StreamingContext,
+    host: String,
+    port: Int,
+    bytesToObjects: InputStream => Iterator[T],
+    storageLevel: StorageLevel
+  ) extends NetworkInputDStream[T](ssc_) {
+
+  def createReceiver(): NetworkReceiver[T] = {
+    new SocketReceiver(id, host, port, bytesToObjects, storageLevel)
+  }
+}
+
+
+class SocketReceiver[T: ClassManifest](
+    streamId: Int,
+    host: String,
+    port: Int,
+    bytesToObjects: InputStream => Iterator[T],
+    storageLevel: StorageLevel
+  ) extends NetworkReceiver[T](streamId) {
+
+  lazy protected val dataHandler = new DataHandler(this, storageLevel)
+
+  override def getLocationPreference = None
+
+  protected def onStart() {
+    logInfo("Connecting to " + host + ":" + port)
+    val socket = new Socket(host, port)
+    logInfo("Connected to " + host + ":" + port)
+    dataHandler.start()
+    val iterator = bytesToObjects(socket.getInputStream())
+    while(iterator.hasNext) {
+      val obj = iterator.next
+      dataHandler += obj
+    }
+  }
+
+  protected def onStop() {
+    dataHandler.stop()
+  }
+
+}
+
+
+object SocketReceiver  {
+
+  /**
+   * This methods translates the data from an inputstream (say, from a socket)
+   * to '\n' delimited strings and returns an iterator to access the strings.
+   */
+  def bytesToLines(inputStream: InputStream): Iterator[String] = {
+    val dataInputStream = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"))
+
+    val iterator = new Iterator[String] {
+      var gotNext = false
+      var finished = false
+      var nextValue: String = null
+
+      private def getNext() {
+        try {
+          nextValue = dataInputStream.readLine()
+          if (nextValue == null) {
+            finished = true
+          }
+        }
+        gotNext = true
+      }
+
+      override def hasNext: Boolean = {
+        if (!finished) {
+          if (!gotNext) {
+            getNext()
+            if (finished) {
+              dataInputStream.close()
+            }
+          }
+        }
+        !finished
+      }
+
+      override def next(): String = {
+        if (finished) {
+          throw new NoSuchElementException("End of stream")
+        }
+        if (!gotNext) {
+          getNext()
+        }
+        gotNext = false
+        nextValue
+      }
+    }
+    iterator
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
new file mode 100644
index 0000000000..6e190b5564
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
@@ -0,0 +1,83 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.Partitioner
+import spark.SparkContext._
+import spark.storage.StorageLevel
+import spark.streaming.{Time, DStream}
+
+class StateDStream[K: ClassManifest, V: ClassManifest, S <: AnyRef : ClassManifest](
+    parent: DStream[(K, V)],
+    updateFunc: (Iterator[(K, Seq[V], Option[S])]) => Iterator[(K, S)],
+    partitioner: Partitioner,
+    preservePartitioning: Boolean
+  ) extends DStream[(K, S)](parent.ssc) {
+
+  super.persist(StorageLevel.MEMORY_ONLY_SER)
+
+  override def dependencies = List(parent)
+
+  override def slideTime = parent.slideTime
+
+  override val mustCheckpoint = true
+
+  override def compute(validTime: Time): Option[RDD[(K, S)]] = {
+
+    // Try to get the previous state RDD
+    getOrCompute(validTime - slideTime) match {
+
+      case Some(prevStateRDD) => {    // If previous state RDD exists
+
+        // Try to get the parent RDD
+        parent.getOrCompute(validTime) match {
+          case Some(parentRDD) => {   // If parent RDD exists, then compute as usual
+
+            // Define the function for the mapPartition operation on cogrouped RDD;
+            // first map the cogrouped tuple to tuples of required type,
+            // and then apply the update function
+            val updateFuncLocal = updateFunc
+            val finalFunc = (iterator: Iterator[(K, (Seq[V], Seq[S]))]) => {
+              val i = iterator.map(t => {
+                (t._1, t._2._1, t._2._2.headOption)
+              })
+              updateFuncLocal(i)
+            }
+            val cogroupedRDD = parentRDD.cogroup(prevStateRDD, partitioner)
+            val stateRDD = cogroupedRDD.mapPartitions(finalFunc, preservePartitioning)
+            //logDebug("Generating state RDD for time " + validTime)
+            return Some(stateRDD)
+          }
+          case None => {    // If parent RDD does not exist, then return old state RDD
+            return Some(prevStateRDD)
+          }
+        }
+      }
+
+      case None => {    // If previous session RDD does not exist (first input data)
+
+        // Try to get the parent RDD
+        parent.getOrCompute(validTime) match {
+          case Some(parentRDD) => {   // If parent RDD exists, then compute as usual
+
+            // Define the function for the mapPartition operation on grouped RDD;
+            // first map the grouped tuple to tuples of required type,
+            // and then apply the update function
+            val updateFuncLocal = updateFunc
+            val finalFunc = (iterator: Iterator[(K, Seq[V])]) => {
+              updateFuncLocal(iterator.map(tuple => (tuple._1, tuple._2, None)))
+            }
+
+            val groupedRDD = parentRDD.groupByKey(partitioner)
+            val sessionRDD = groupedRDD.mapPartitions(finalFunc, preservePartitioning)
+            //logDebug("Generating state RDD for time " + validTime + " (first)")
+            return Some(sessionRDD)
+          }
+          case None => { // If parent RDD does not exist, then nothing to do!
+            //logDebug("Not generating state RDD (no previous state, no parent)")
+            return None
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/TransformedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/TransformedDStream.scala
new file mode 100644
index 0000000000..0337579514
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/TransformedDStream.scala
@@ -0,0 +1,19 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.streaming.{DStream, Time}
+
+private[streaming]
+class TransformedDStream[T: ClassManifest, U: ClassManifest] (
+    parent: DStream[T],
+    transformFunc: (RDD[T], Time) => RDD[U]
+  ) extends DStream[U](parent.ssc) {
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = parent.slideTime
+
+  override def compute(validTime: Time): Option[RDD[U]] = {
+    parent.getOrCompute(validTime).map(transformFunc(_, validTime))
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
new file mode 100644
index 0000000000..f1efb2ae72
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
@@ -0,0 +1,39 @@
+package spark.streaming.dstream
+
+import spark.streaming.{DStream, Time}
+import spark.RDD
+import collection.mutable.ArrayBuffer
+import spark.rdd.UnionRDD
+
+class UnionDStream[T: ClassManifest](parents: Array[DStream[T]])
+  extends DStream[T](parents.head.ssc) {
+
+  if (parents.length == 0) {
+    throw new IllegalArgumentException("Empty array of parents")
+  }
+
+  if (parents.map(_.ssc).distinct.size > 1) {
+    throw new IllegalArgumentException("Array of parents have different StreamingContexts")
+  }
+
+  if (parents.map(_.slideTime).distinct.size > 1) {
+    throw new IllegalArgumentException("Array of parents have different slide times")
+  }
+
+  override def dependencies = parents.toList
+
+  override def slideTime: Time = parents.head.slideTime
+
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    val rdds = new ArrayBuffer[RDD[T]]()
+    parents.map(_.getOrCompute(validTime)).foreach(_ match {
+      case Some(rdd) => rdds += rdd
+      case None => throw new Exception("Could not generate RDD from a parent for unifying at time " + validTime)
+    })
+    if (rdds.size > 0) {
+      Some(new UnionRDD(ssc.sc, rdds))
+    } else {
+      None
+    }
+  }
+}
diff --git a/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
new file mode 100644
index 0000000000..4b2621c497
--- /dev/null
+++ b/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
@@ -0,0 +1,40 @@
+package spark.streaming.dstream
+
+import spark.RDD
+import spark.rdd.UnionRDD
+import spark.storage.StorageLevel
+import spark.streaming.{Interval, Time, DStream}
+
+
+class WindowedDStream[T: ClassManifest](
+    parent: DStream[T],
+    _windowTime: Time,
+    _slideTime: Time) 
+  extends DStream[T](parent.ssc) {
+
+  if (!_windowTime.isMultipleOf(parent.slideTime))
+    throw new Exception("The window duration of WindowedDStream (" + _slideTime + ") " +
+    "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")")
+
+  if (!_slideTime.isMultipleOf(parent.slideTime))
+    throw new Exception("The slide duration of WindowedDStream (" + _slideTime + ") " +
+    "must be multiple of the slide duration of parent DStream (" + parent.slideTime + ")")
+
+  parent.persist(StorageLevel.MEMORY_ONLY_SER)
+
+  def windowTime: Time =  _windowTime
+
+  override def dependencies = List(parent)
+
+  override def slideTime: Time = _slideTime
+
+  override def parentRememberDuration: Time = rememberDuration + windowTime
+
+  override def compute(validTime: Time): Option[RDD[T]] = {
+    val currentWindow = Interval(validTime - windowTime + parent.slideTime, validTime)
+    Some(new UnionRDD(ssc.sc, parent.slice(currentWindow)))
+  }
+}
+
+
+
diff --git a/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala b/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
index 7c4ee3b34c..dfaaf03f03 100644
--- a/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/GrepRaw.scala
@@ -25,7 +25,7 @@ object GrepRaw {
 
     val rawStreams = (1 to numStreams).map(_ =>
       ssc.rawNetworkStream[String](host, port, StorageLevel.MEMORY_ONLY_SER_2)).toArray
-    val union = new UnionDStream(rawStreams)
+    val union = ssc.union(rawStreams)
     union.filter(_.contains("Alice")).count().foreach(r =>
       println("Grep count: " + r.collect().mkString))
     ssc.start()
diff --git a/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala b/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
index 182dfd8a52..338834bc3c 100644
--- a/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/TopKWordCountRaw.scala
@@ -34,7 +34,7 @@ object TopKWordCountRaw {
     val lines = (1 to numStreams).map(_ => {
         ssc.rawNetworkStream[String]("localhost", port, StorageLevel.MEMORY_ONLY_SER_2)
     })
-    val union = new UnionDStream(lines.toArray)
+    val union = ssc.union(lines)
     val counts = union.mapPartitions(splitAndCountPartitions)
     val windowedCounts = counts.reduceByKeyAndWindow(add _, subtract _, Seconds(30), Seconds(1), 10)
     val partialTopKWindowedCounts = windowedCounts.mapPartitions(topK(_, k))
diff --git a/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala b/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
index 9bcd30f4d7..d93335a8ce 100644
--- a/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
+++ b/streaming/src/main/scala/spark/streaming/examples/WordCountRaw.scala
@@ -33,7 +33,7 @@ object WordCountRaw {
     val lines = (1 to numStreams).map(_ => {
         ssc.rawNetworkStream[String]("localhost", port, StorageLevel.MEMORY_ONLY_SER_2)
     })
-    val union = new UnionDStream(lines.toArray)
+    val union = ssc.union(lines)
     val counts = union.mapPartitions(splitAndCountPartitions)
     val windowedCounts = counts.reduceByKeyAndWindow(add _, subtract _, Seconds(30), Seconds(1), 10)
     windowedCounts.foreach(r => println("# unique words = " + r.count()))
diff --git a/streaming/src/main/scala/spark/streaming/input/KafkaInputDStream.scala b/streaming/src/main/scala/spark/streaming/input/KafkaInputDStream.scala
deleted file mode 100644
index 7c642d4802..0000000000
--- a/streaming/src/main/scala/spark/streaming/input/KafkaInputDStream.scala
+++ /dev/null
@@ -1,193 +0,0 @@
-package spark.streaming
-
-import java.util.Properties
-import java.util.concurrent.Executors
-import kafka.consumer._
-import kafka.message.{Message, MessageSet, MessageAndMetadata}
-import kafka.serializer.StringDecoder
-import kafka.utils.{Utils, ZKGroupTopicDirs}
-import kafka.utils.ZkUtils._
-import scala.collection.mutable.HashMap
-import scala.collection.JavaConversions._
-import spark._
-import spark.RDD
-import spark.storage.StorageLevel
-
-// Key for a specific Kafka Partition: (broker, topic, group, part)
-case class KafkaPartitionKey(brokerId: Int, topic: String, groupId: String, partId: Int)
-// NOT USED - Originally intended for fault-tolerance
-// Metadata for a Kafka Stream that it sent to the Master
-case class KafkaInputDStreamMetadata(timestamp: Long, data: Map[KafkaPartitionKey, Long])
-// NOT USED - Originally intended for fault-tolerance
-// Checkpoint data specific to a KafkaInputDstream
-case class KafkaDStreamCheckpointData(kafkaRdds: HashMap[Time, Any], 
-  savedOffsets: Map[KafkaPartitionKey, Long]) extends DStreamCheckpointData(kafkaRdds)
-
-/**
- * Input stream that pulls messages form a Kafka Broker.
- * 
- * @param host Zookeper hostname.
- * @param port Zookeper port.
- * @param groupId The group id for this consumer.
- * @param topics Map of (topic_name -> numPartitions) to consume. Each partition is consumed
- * in its own thread.
- * @param initialOffsets Optional initial offsets for each of the partitions to consume.
- * By default the value is pulled from zookeper.
- * @param storageLevel RDD storage level.
- */
-class KafkaInputDStream[T: ClassManifest](
-    @transient ssc_ : StreamingContext,
-    host: String,
-    port: Int,
-    groupId: String,
-    topics: Map[String, Int],
-    initialOffsets: Map[KafkaPartitionKey, Long],
-    storageLevel: StorageLevel
-  ) extends NetworkInputDStream[T](ssc_ ) with Logging {
-
-  // Metadata that keeps track of which messages have already been consumed.
-  var savedOffsets = HashMap[Long, Map[KafkaPartitionKey, Long]]()
-  
-  /* NOT USED - Originally intended for fault-tolerance
- 
-  // In case of a failure, the offets for a particular timestamp will be restored.
-  @transient var restoredOffsets : Map[KafkaPartitionKey, Long] = null
-
- 
-  override protected[streaming] def addMetadata(metadata: Any) {
-    metadata match {
-      case x : KafkaInputDStreamMetadata =>
-        savedOffsets(x.timestamp) = x.data
-        // TOOD: Remove logging
-        logInfo("New saved Offsets: " + savedOffsets)
-      case _ => logInfo("Received unknown metadata: " + metadata.toString)
-    }
-  }
-
-  override protected[streaming] def updateCheckpointData(currentTime: Time) {
-    super.updateCheckpointData(currentTime)
-    if(savedOffsets.size > 0) {
-      // Find the offets that were stored before the checkpoint was initiated
-      val key = savedOffsets.keys.toList.sortWith(_ < _).filter(_ < currentTime.millis).last
-      val latestOffsets = savedOffsets(key)
-      logInfo("Updating KafkaDStream checkpoint data: " + latestOffsets.toString)
-      checkpointData = KafkaDStreamCheckpointData(checkpointData.rdds, latestOffsets)
-      // TODO: This may throw out offsets that are created after the checkpoint,
-      // but it's unlikely we'll need them.
-      savedOffsets.clear()
-    }
-  }
-
-  override protected[streaming] def restoreCheckpointData() {
-    super.restoreCheckpointData()
-    logInfo("Restoring KafkaDStream checkpoint data.")
-    checkpointData match { 
-      case x : KafkaDStreamCheckpointData => 
-        restoredOffsets = x.savedOffsets
-        logInfo("Restored KafkaDStream offsets: " + savedOffsets)
-    }
-  } */
-
-  def createReceiver(): NetworkReceiver[T] = {
-    new KafkaReceiver(id, host, port,  groupId, topics, initialOffsets, storageLevel)
-        .asInstanceOf[NetworkReceiver[T]]
-  }
-}
-
-class KafkaReceiver(streamId: Int, host: String, port: Int, groupId: String, 
-  topics: Map[String, Int], initialOffsets: Map[KafkaPartitionKey, Long], 
-  storageLevel: StorageLevel) extends NetworkReceiver[Any](streamId) {
-
-  // Timeout for establishing a connection to Zookeper in ms.
-  val ZK_TIMEOUT = 10000
-
-  // Handles pushing data into the BlockManager
-  lazy protected val dataHandler = new DataHandler(this, storageLevel)
-  // Keeps track of the current offsets. Maps from (broker, topic, group, part) -> Offset
-  lazy val offsets = HashMap[KafkaPartitionKey, Long]()
-  // Connection to Kafka
-  var consumerConnector : ZookeeperConsumerConnector = null
-
-  def onStop() {
-    dataHandler.stop()
-  }
-
-  def onStart() {
-
-    // Starting the DataHandler that buffers blocks and pushes them into them BlockManager
-    dataHandler.start()
-
-    // In case we are using multiple Threads to handle Kafka Messages
-    val executorPool = Executors.newFixedThreadPool(topics.values.reduce(_ + _))
-
-    val zooKeeperEndPoint = host + ":" + port
-    logInfo("Starting Kafka Consumer Stream with group: " + groupId)
-    logInfo("Initial offsets: " + initialOffsets.toString)
-    
-    // Zookeper connection properties
-    val props = new Properties()
-    props.put("zk.connect", zooKeeperEndPoint)
-    props.put("zk.connectiontimeout.ms", ZK_TIMEOUT.toString)
-    props.put("groupid", groupId)
-
-    // Create the connection to the cluster
-    logInfo("Connecting to Zookeper: " + zooKeeperEndPoint)
-    val consumerConfig = new ConsumerConfig(props)
-    consumerConnector = Consumer.create(consumerConfig).asInstanceOf[ZookeeperConsumerConnector]
-    logInfo("Connected to " + zooKeeperEndPoint)
-
-    // Reset the Kafka offsets in case we are recovering from a failure
-    resetOffsets(initialOffsets)
-
-    // Create Threads for each Topic/Message Stream we are listening
-    val topicMessageStreams = consumerConnector.createMessageStreams(topics, new StringDecoder())
-
-    // Start the messages handler for each partition
-    topicMessageStreams.values.foreach { streams =>
-      streams.foreach { stream => executorPool.submit(new MessageHandler(stream)) }
-    }
-
-  }
-
-  // Overwrites the offets in Zookeper.
-  private def resetOffsets(offsets: Map[KafkaPartitionKey, Long]) {
-    offsets.foreach { case(key, offset) =>
-      val topicDirs = new ZKGroupTopicDirs(key.groupId, key.topic)
-      val partitionName = key.brokerId + "-" + key.partId
-      updatePersistentPath(consumerConnector.zkClient, 
-        topicDirs.consumerOffsetDir + "/" + partitionName, offset.toString)
-    }
-  }
-
-  // Handles Kafka Messages
-  private class MessageHandler(stream: KafkaStream[String]) extends Runnable {
-    def run() {
-      logInfo("Starting MessageHandler.")
-      stream.takeWhile { msgAndMetadata => 
-        dataHandler += msgAndMetadata.message
-
-        // Updating the offet. The key is (broker, topic, group, partition).
-        val key = KafkaPartitionKey(msgAndMetadata.topicInfo.brokerId, msgAndMetadata.topic, 
-          groupId, msgAndMetadata.topicInfo.partition.partId)
-        val offset = msgAndMetadata.topicInfo.getConsumeOffset
-        offsets.put(key, offset)
-        // logInfo("Handled message: " + (key, offset).toString)
-
-        // Keep on handling messages
-        true
-      }  
-    }
-  }
-
-  // NOT USED - Originally intended for fault-tolerance
-  // class KafkaDataHandler(receiver: KafkaReceiver, storageLevel: StorageLevel) 
-  // extends DataHandler[Any](receiver, storageLevel) {
-
-  //   override def createBlock(blockId: String, iterator: Iterator[Any]) : Block = {
-  //     // Creates a new Block with Kafka-specific Metadata
-  //     new Block(blockId, iterator, KafkaInputDStreamMetadata(System.currentTimeMillis, offsets.toMap))
-  //   }
-
-  // }
-
-}
diff --git a/streaming/src/test/scala/spark/streaming/CheckpointSuite.scala b/streaming/src/test/scala/spark/streaming/CheckpointSuite.scala
index 0d82b2f1ea..920388bba9 100644
--- a/streaming/src/test/scala/spark/streaming/CheckpointSuite.scala
+++ b/streaming/src/test/scala/spark/streaming/CheckpointSuite.scala
@@ -42,7 +42,7 @@ class CheckpointSuite extends TestSuiteBase with BeforeAndAfter {
     val stateStreamCheckpointInterval = Seconds(1)
 
     // this ensure checkpointing occurs at least once
-    val firstNumBatches = (stateStreamCheckpointInterval.millis / batchDuration.millis) * 2
+    val firstNumBatches = (stateStreamCheckpointInterval / batchDuration) * 2
     val secondNumBatches = firstNumBatches
 
     // Setup the streams
diff --git a/streaming/src/test/scala/spark/streaming/FailureSuite.scala b/streaming/src/test/scala/spark/streaming/FailureSuite.scala
index 5b414117fc..4aa428bf64 100644
--- a/streaming/src/test/scala/spark/streaming/FailureSuite.scala
+++ b/streaming/src/test/scala/spark/streaming/FailureSuite.scala
@@ -133,7 +133,7 @@ class FailureSuite extends TestSuiteBase with BeforeAndAfter {
     // Get the output buffer
     val outputStream = ssc.graph.getOutputStreams.head.asInstanceOf[TestOutputStream[V]]
     val output = outputStream.output
-    val waitTime = (batchDuration.millis * (numBatches.toDouble + 0.5)).toLong
+    val waitTime = (batchDuration.milliseconds * (numBatches.toDouble + 0.5)).toLong
     val startTime = System.currentTimeMillis()
 
     try {
diff --git a/streaming/src/test/scala/spark/streaming/InputStreamsSuite.scala b/streaming/src/test/scala/spark/streaming/InputStreamsSuite.scala
index ed9a659092..76b528bec3 100644
--- a/streaming/src/test/scala/spark/streaming/InputStreamsSuite.scala
+++ b/streaming/src/test/scala/spark/streaming/InputStreamsSuite.scala
@@ -1,5 +1,6 @@
 package spark.streaming
 
+import dstream.SparkFlumeEvent
 import java.net.{InetSocketAddress, SocketException, Socket, ServerSocket}
 import java.io.{File, BufferedWriter, OutputStreamWriter}
 import java.util.concurrent.{TimeUnit, ArrayBlockingQueue}
diff --git a/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala b/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
index a44f738957..28bdd53c3c 100644
--- a/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
+++ b/streaming/src/test/scala/spark/streaming/TestSuiteBase.scala
@@ -1,12 +1,16 @@
 package spark.streaming
 
+import spark.streaming.dstream.{InputDStream, ForEachDStream}
+import spark.streaming.util.ManualClock
+
 import spark.{RDD, Logging}
-import util.ManualClock
+
 import collection.mutable.ArrayBuffer
-import org.scalatest.FunSuite
 import collection.mutable.SynchronizedBuffer
+
 import java.io.{ObjectInputStream, IOException}
 
+import org.scalatest.FunSuite
 
 /**
  * This is a input stream just for the testsuites. This is equivalent to a checkpointable,
@@ -70,6 +74,10 @@ trait TestSuiteBase extends FunSuite with Logging {
 
   def actuallyWait = false
 
+  /**
+   * Set up required DStreams to test the DStream operation using the two sequences
+   * of input collections.
+   */
   def setupStreams[U: ClassManifest, V: ClassManifest](
       input: Seq[Seq[U]],
       operation: DStream[U] => DStream[V]
@@ -90,6 +98,10 @@ trait TestSuiteBase extends FunSuite with Logging {
     ssc
   }
 
+  /**
+   * Set up required DStreams to test the binary operation using the sequence
+   * of input collections.
+   */
   def setupStreams[U: ClassManifest, V: ClassManifest, W: ClassManifest](
       input1: Seq[Seq[U]],
       input2: Seq[Seq[V]],
@@ -173,6 +185,11 @@ trait TestSuiteBase extends FunSuite with Logging {
     output
   }
 
+  /**
+   * Verify whether the output values after running a DStream operation
+   * is same as the expected output values, by comparing the output
+   * collections either as lists (order matters) or sets (order does not matter)
+   */
   def verifyOutput[V: ClassManifest](
       output: Seq[Seq[V]],
       expectedOutput: Seq[Seq[V]],
@@ -199,6 +216,10 @@ trait TestSuiteBase extends FunSuite with Logging {
     logInfo("Output verified successfully")
   }
 
+  /**
+   * Test unary DStream operation with a list of inputs, with number of
+   * batches to run same as the number of expected output values
+   */
   def testOperation[U: ClassManifest, V: ClassManifest](
       input: Seq[Seq[U]],
       operation: DStream[U] => DStream[V],
@@ -208,6 +229,15 @@ trait TestSuiteBase extends FunSuite with Logging {
     testOperation[U, V](input, operation, expectedOutput, -1, useSet)
   }
 
+  /**
+   * Test unary DStream operation with a list of inputs
+   * @param input      Sequence of input collections
+   * @param operation  Binary DStream operation to be applied to the 2 inputs
+   * @param expectedOutput Sequence of expected output collections
+   * @param numBatches Number of batches to run the operation for
+   * @param useSet     Compare the output values with the expected output values
+   *                   as sets (order matters) or as lists (order does not matter)
+   */
   def testOperation[U: ClassManifest, V: ClassManifest](
       input: Seq[Seq[U]],
       operation: DStream[U] => DStream[V],
@@ -221,6 +251,10 @@ trait TestSuiteBase extends FunSuite with Logging {
     verifyOutput[V](output, expectedOutput, useSet)
   }
 
+  /**
+   * Test binary DStream operation with two lists of inputs, with number of
+   * batches to run same as the number of expected output values
+   */
   def testOperation[U: ClassManifest, V: ClassManifest, W: ClassManifest](
       input1: Seq[Seq[U]],
       input2: Seq[Seq[V]],
@@ -231,6 +265,16 @@ trait TestSuiteBase extends FunSuite with Logging {
     testOperation[U, V, W](input1, input2, operation, expectedOutput, -1, useSet)
   }
 
+  /**
+   * Test binary DStream operation with two lists of inputs
+   * @param input1     First sequence of input collections
+   * @param input2     Second sequence of input collections
+   * @param operation  Binary DStream operation to be applied to the 2 inputs
+   * @param expectedOutput Sequence of expected output collections
+   * @param numBatches Number of batches to run the operation for
+   * @param useSet     Compare the output values with the expected output values
+   *                   as sets (order matters) or as lists (order does not matter)
+   */
   def testOperation[U: ClassManifest, V: ClassManifest, W: ClassManifest](
       input1: Seq[Seq[U]],
       input2: Seq[Seq[V]],
diff --git a/streaming/src/test/scala/spark/streaming/WindowOperationsSuite.scala b/streaming/src/test/scala/spark/streaming/WindowOperationsSuite.scala
index 3e20e16708..4bc5229465 100644
--- a/streaming/src/test/scala/spark/streaming/WindowOperationsSuite.scala
+++ b/streaming/src/test/scala/spark/streaming/WindowOperationsSuite.scala
@@ -209,7 +209,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     val expectedOutput = bigGroupByOutput.map(_.map(x => (x._1, x._2.toSet)))
     val windowTime = Seconds(2)
     val slideTime = Seconds(1)
-    val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+    val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
     val operation = (s: DStream[(String, Int)]) => {
       s.groupByKeyAndWindow(windowTime, slideTime)
        .map(x => (x._1, x._2.toSet))
@@ -223,7 +223,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     val expectedOutput = Seq( Seq(1), Seq(2), Seq(3), Seq(3), Seq(1), Seq(0))
     val windowTime = Seconds(2)
     val slideTime = Seconds(1)
-    val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+    val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
     val operation = (s: DStream[Int]) => s.countByWindow(windowTime, slideTime)
     testOperation(input, operation, expectedOutput, numBatches, true)
   }
@@ -233,7 +233,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     val expectedOutput = Seq( Seq(("a", 1)), Seq(("a", 1), ("b", 2)), Seq(("a", 1), ("b", 3)))
     val windowTime = Seconds(2)
     val slideTime = Seconds(1)
-    val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+    val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
     val operation = (s: DStream[(String, Int)]) => {
       s.countByKeyAndWindow(windowTime, slideTime).map(x => (x._1, x._2.toInt))
     }
@@ -251,7 +251,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     slideTime: Time = Seconds(1)
     ) {
     test("window - " + name) {
-      val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+      val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
       val operation = (s: DStream[Int]) => s.window(windowTime, slideTime)
       testOperation(input, operation, expectedOutput, numBatches, true)
     }
@@ -265,7 +265,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     slideTime: Time = Seconds(1)
     ) {
     test("reduceByKeyAndWindow - " + name) {
-      val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+      val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
       val operation = (s: DStream[(String, Int)]) => {
         s.reduceByKeyAndWindow(_ + _, windowTime, slideTime).persist()
       }
@@ -281,7 +281,7 @@ class WindowOperationsSuite extends TestSuiteBase {
     slideTime: Time = Seconds(1)
   ) {
     test("reduceByKeyAndWindowInv - " + name) {
-      val numBatches = expectedOutput.size * (slideTime.millis / batchDuration.millis).toInt
+      val numBatches = expectedOutput.size * (slideTime / batchDuration).toInt
       val operation = (s: DStream[(String, Int)]) => {
         s.reduceByKeyAndWindow(_ + _, _ - _, windowTime, slideTime)
          .persist()
-- 
cgit v1.2.3


From 18b9b3b99fd753899d19bd10f0dbef7d5c4ae8d7 Mon Sep 17 00:00:00 2001
From: Tathagata Das <tathagata.das1565@gmail.com>
Date: Sun, 30 Dec 2012 20:00:42 -0800
Subject: More classes made private[streaming] to hide from scala docs.

---
 .gitignore                                         |   2 +
 .../src/main/scala/spark/streaming/DStream.scala   |   2 +-
 .../main/scala/spark/streaming/JobManager.scala    |   2 +-
 .../src/main/scala/spark/streaming/Scheduler.scala |   2 +-
 .../scala/spark/streaming/StreamingContext.scala   | 108 ++++++++++++++++-----
 .../src/main/scala/spark/streaming/Time.scala      |  30 ++++--
 .../spark/streaming/dstream/CoGroupedDStream.scala |   1 +
 .../spark/streaming/dstream/FileInputDStream.scala |   2 +-
 .../streaming/dstream/FlumeInputDStream.scala      |  13 ++-
 .../streaming/dstream/KafkaInputDStream.scala      |   6 +-
 .../spark/streaming/dstream/RawInputDStream.scala  |   2 +
 .../streaming/dstream/ReducedWindowedDStream.scala |   1 +
 .../streaming/dstream/SocketInputDStream.scala     |   5 +-
 .../spark/streaming/dstream/StateDStream.scala     |   1 +
 .../spark/streaming/dstream/UnionDStream.scala     |   1 +
 .../spark/streaming/dstream/WindowedDStream.scala  |   2 +-
 .../main/scala/spark/streaming/util/Clock.scala    |   8 +-
 .../spark/streaming/util/RecurringTimer.scala      |   1 +
 18 files changed, 137 insertions(+), 52 deletions(-)

(limited to 'streaming')

diff --git a/.gitignore b/.gitignore
index c207409e3c..88d7b56181 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@ third_party/libmesos.so
 third_party/libmesos.dylib
 conf/java-opts
 conf/spark-env.sh
+conf/streaming-env.sh
 conf/log4j.properties
 docs/_site
 docs/api
@@ -31,4 +32,5 @@ project/plugins/src_managed/
 logs/
 log/
 spark-tests.log
+streaming-tests.log
 dependency-reduced-pom.xml
diff --git a/streaming/src/main/scala/spark/streaming/DStream.scala b/streaming/src/main/scala/spark/streaming/DStream.scala
index 292ad3b9f9..beba9cfd4f 100644
--- a/streaming/src/main/scala/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/spark/streaming/DStream.scala
@@ -189,7 +189,7 @@ abstract class DStream[T: ClassManifest] (
     val metadataCleanerDelay = spark.util.MetadataCleaner.getDelaySeconds
     logInfo("metadataCleanupDelay = " + metadataCleanerDelay)
     assert(
-      metadataCleanerDelay < 0 || rememberDuration < metadataCleanerDelay * 1000,
+      metadataCleanerDelay < 0 || rememberDuration.milliseconds < metadataCleanerDelay * 1000,
       "It seems you are doing some DStream window operation or setting a checkpoint interval " +
         "which requires " + this.getClass.getSimpleName + " to remember generated RDDs for more " +
         "than " + rememberDuration.milliseconds + " milliseconds. But the Spark's metadata cleanup" +
diff --git a/streaming/src/main/scala/spark/streaming/JobManager.scala b/streaming/src/main/scala/spark/streaming/JobManager.scala
index fda7264a27..3b910538e0 100644
--- a/streaming/src/main/scala/spark/streaming/JobManager.scala
+++ b/streaming/src/main/scala/spark/streaming/JobManager.scala
@@ -14,7 +14,7 @@ class JobManager(ssc: StreamingContext, numThreads: Int = 1) extends Logging {
       try {
         val timeTaken = job.run()
         logInfo("Total delay: %.5f s for job %s (execution: %.5f s)".format(
-          (System.currentTimeMillis() - job.time) / 1000.0, job.id, timeTaken / 1000.0))
+          (System.currentTimeMillis() - job.time.milliseconds) / 1000.0, job.id, timeTaken / 1000.0))
       } catch {
         case e: Exception =>
           logError("Running " + job + " failed", e)
diff --git a/streaming/src/main/scala/spark/streaming/Scheduler.scala b/streaming/src/main/scala/spark/streaming/Scheduler.scala
index aeb7c3eb0e..eb40affe6d 100644
--- a/streaming/src/main/scala/spark/streaming/Scheduler.scala
+++ b/streaming/src/main/scala/spark/streaming/Scheduler.scala
@@ -22,7 +22,7 @@ class Scheduler(ssc: StreamingContext) extends Logging {
 
   val clockClass = System.getProperty("spark.streaming.clock", "spark.streaming.util.SystemClock")
   val clock = Class.forName(clockClass).newInstance().asInstanceOf[Clock]
-  val timer = new RecurringTimer(clock, ssc.graph.batchDuration, generateRDDs(_))
+  val timer = new RecurringTimer(clock, ssc.graph.batchDuration.milliseconds, generateRDDs(_))
 
   def start() {
     // If context was started from checkpoint, then restart timer such that
diff --git a/streaming/src/main/scala/spark/streaming/StreamingContext.scala b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
index ef73049a81..7256e41af9 100644
--- a/streaming/src/main/scala/spark/streaming/StreamingContext.scala
+++ b/streaming/src/main/scala/spark/streaming/StreamingContext.scala
@@ -15,7 +15,6 @@ import org.apache.hadoop.io.LongWritable
 import org.apache.hadoop.io.Text
 import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
 import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
-import org.apache.flume.source.avro.AvroFlumeEvent
 import org.apache.hadoop.fs.Path
 import java.util.UUID
 
@@ -101,14 +100,27 @@ class StreamingContext private (
   protected[streaming] var receiverJobThread: Thread = null
   protected[streaming] var scheduler: Scheduler = null
 
+  /**
+   * Sets each DStreams in this context to remember RDDs it generated in the last given duration.
+   * DStreams remember RDDs only for a limited duration of time and releases them for garbage
+   * collection. This method allows the developer to specify how to long to remember the RDDs (
+   * if the developer wishes to query old data outside the DStream computation).
+   * @param duration Minimum duration that each DStream should remember its RDDs
+   */
   def remember(duration: Time) {
     graph.remember(duration)
   }
 
-  def checkpoint(dir: String, interval: Time = null) {
-    if (dir != null) {
-      sc.setCheckpointDir(StreamingContext.getSparkCheckpointDir(dir))
-      checkpointDir = dir
+  /**
+   * Sets the context to periodically checkpoint the DStream operations for master
+   * fault-tolerance. By default, the graph will be checkpointed every batch interval.
+   * @param directory HDFS-compatible directory where the checkpoint data will be reliably stored
+   * @param interval checkpoint interval
+   */
+  def checkpoint(directory: String, interval: Time = null) {
+    if (directory != null) {
+      sc.setCheckpointDir(StreamingContext.getSparkCheckpointDir(directory))
+      checkpointDir = directory
       checkpointInterval = interval
     } else {
       checkpointDir = null
@@ -122,9 +134,8 @@ class StreamingContext private (
 
   protected[streaming] def getNewNetworkStreamId() = nextNetworkInputStreamId.getAndIncrement()
 
- /**
+  /**
    * Create an input stream that pulls messages form a Kafka Broker.
-   * 
    * @param hostname Zookeper hostname.
    * @param port Zookeper port.
    * @param groupId The group id for this consumer.
@@ -147,6 +158,15 @@ class StreamingContext private (
     inputStream
   }
 
+  /**
+   * Create a input stream from network source hostname:port. Data is received using
+   * a TCP socket and the receive bytes is interpreted as UTF8 encoded \n delimited
+   * lines.
+   * @param hostname      Hostname to connect to for receiving data
+   * @param port          Port to connect to for receiving data
+   * @param storageLevel  Storage level to use for storing the received objects
+   *                      (default: StorageLevel.MEMORY_AND_DISK_SER_2)
+   */
   def networkTextStream(
       hostname: String,
       port: Int,
@@ -155,6 +175,16 @@ class StreamingContext private (
     networkStream[String](hostname, port, SocketReceiver.bytesToLines, storageLevel)
   }
 
+  /**
+   * Create a input stream from network source hostname:port. Data is received using
+   * a TCP socket and the receive bytes it interepreted as object using the given
+   * converter.
+   * @param hostname      Hostname to connect to for receiving data
+   * @param port          Port to connect to for receiving data
+   * @param converter     Function to convert the byte stream to objects
+   * @param storageLevel  Storage level to use for storing the received objects
+   * @tparam T            Type of the objects received (after converting bytes to objects)
+   */
   def networkStream[T: ClassManifest](
       hostname: String,
       port: Int,
@@ -166,16 +196,32 @@ class StreamingContext private (
     inputStream
   }
 
+  /**
+   * Creates a input stream from a Flume source.
+   * @param hostname Hostname of the slave machine to which the flume data will be sent
+   * @param port     Port of the slave machine to which the flume data will be sent
+   * @param storageLevel  Storage level to use for storing the received objects
+   */
   def flumeStream (
-    hostname: String,
-    port: Int,
-    storageLevel: StorageLevel = StorageLevel.MEMORY_AND_DISK_SER_2): DStream[SparkFlumeEvent] = {
+      hostname: String,
+      port: Int,
+      storageLevel: StorageLevel = StorageLevel.MEMORY_AND_DISK_SER_2
+    ): DStream[SparkFlumeEvent] = {
     val inputStream = new FlumeInputDStream(this, hostname, port, storageLevel)
     graph.addInputStream(inputStream)
     inputStream
   }
 
-
+  /**
+   * Create a input stream from network source hostname:port, where data is received
+   * as serialized blocks (serialized using the Spark's serializer) that can be directly
+   * pushed into the block manager without deserializing them. This is the most efficient
+   * way to receive data.
+   * @param hostname      Hostname to connect to for receiving data
+   * @param port          Port to connect to for receiving data
+   * @param storageLevel  Storage level to use for storing the received objects
+   * @tparam T            Type of the objects in the received blocks
+   */
   def rawNetworkStream[T: ClassManifest](
       hostname: String,
       port: Int,
@@ -188,7 +234,11 @@ class StreamingContext private (
 
   /**
    * Creates a input stream that monitors a Hadoop-compatible filesystem
-   * for new files and executes the necessary processing on them.
+   * for new files and reads them using the given key-value types and input format.
+   * @param directory HDFS directory to monitor for new file
+   * @tparam K Key type for reading HDFS file
+   * @tparam V Value type for reading HDFS file
+   * @tparam F Input format for reading HDFS file
    */
   def fileStream[
     K: ClassManifest,
@@ -200,13 +250,23 @@ class StreamingContext private (
     inputStream
   }
 
+  /**
+   * Creates a input stream that monitors a Hadoop-compatible filesystem
+   * for new files and reads them as text files (using key as LongWritable, value
+   * as Text and input format as TextInputFormat).
+   * @param directory HDFS directory to monitor for new file
+   */
   def textFileStream(directory: String): DStream[String] = {
     fileStream[LongWritable, Text, TextInputFormat](directory).map(_._2.toString)
   }
 
   /**
    * Creates a input stream from an queue of RDDs. In each batch,
-   * it will process either one or all of the RDDs returned by the queue
+   * it will process either one or all of the RDDs returned by the queue.
+   * @param queue      Queue of RDDs
+   * @param oneAtATime Whether only one RDD should be consumed from the queue in every interval
+   * @param defaultRDD Default RDD is returned by the DStream when the queue is empty
+   * @tparam T         Type of objects in the RDD
    */
   def queueStream[T: ClassManifest](
       queue: Queue[RDD[T]],
@@ -218,13 +278,9 @@ class StreamingContext private (
     inputStream
   }
 
-  def queueStream[T: ClassManifest](array: Array[RDD[T]]): DStream[T] = {
-    val queue = new Queue[RDD[T]]
-    val inputStream = queueStream(queue, true, null)
-    queue ++= array
-    inputStream
-  }
-
+  /**
+   * Create a unified DStream from multiple DStreams of the same type and same interval
+   */
   def union[T: ClassManifest](streams: Seq[DStream[T]]): DStream[T] = {
     new UnionDStream[T](streams.toArray)
   }
@@ -256,7 +312,7 @@ class StreamingContext private (
   }
 
   /**
-   * This function starts the execution of the streams.
+   * Starts the execution of the streams.
    */
   def start() {
     if (checkpointDir != null && checkpointInterval == null && graph != null) {
@@ -284,7 +340,7 @@ class StreamingContext private (
   }
 
   /**
-   * This function stops the execution of the streams.
+   * Sstops the execution of the streams.
    */
   def stop() {
     try {
@@ -302,6 +358,10 @@ class StreamingContext private (
 
 object StreamingContext {
 
+  implicit def toPairDStreamFunctions[K: ClassManifest, V: ClassManifest](stream: DStream[(K,V)]) = {
+    new PairDStreamFunctions[K, V](stream)
+  }
+
   protected[streaming] def createNewSparkContext(master: String, frameworkName: String): SparkContext = {
 
     // Set the default cleaner delay to an hour if not already set.
@@ -312,10 +372,6 @@ object StreamingContext {
     new SparkContext(master, frameworkName)
   }
 
-  implicit def toPairDStreamFunctions[K: ClassManifest, V: ClassManifest](stream: DStream[(K,V)]) = {
-    new PairDStreamFunctions[K, V](stream)
-  }
-
   protected[streaming] def rddToFileName[T](prefix: String, suffix: String, time: Time): String = {
     if (prefix == null) {
       time.milliseconds.toString
diff --git a/streaming/src/main/scala/spark/streaming/Time.scala b/streaming/src/main/scala/spark/streaming/Time.scala
index 2976e5e87b..3c6fd5d967 100644
--- a/streaming/src/main/scala/spark/streaming/Time.scala
+++ b/streaming/src/main/scala/spark/streaming/Time.scala
@@ -1,16 +1,18 @@
 package spark.streaming
 
 /**
- * This class is simple wrapper class that represents time in UTC.
- * @param millis Time in UTC long
+ * This is a simple class that represents time. Internally, it represents time as UTC.
+ * The recommended way to create instances of Time is to use helper objects
+ * [[spark.streaming.Milliseconds]], [[spark.streaming.Seconds]], and [[spark.streaming.Minutes]].
+ * @param millis Time in UTC.
  */
 
 case class Time(private val millis: Long) {
   
   def < (that: Time): Boolean = (this.millis < that.millis)
- 
+
   def <= (that: Time): Boolean = (this.millis <= that.millis)
-  
+
   def > (that: Time): Boolean = (this.millis > that.millis)
   
   def >= (that: Time): Boolean = (this.millis >= that.millis)
@@ -45,23 +47,33 @@ case class Time(private val millis: Long) {
   def milliseconds: Long = millis
 }
 
-object Time {
+private[streaming] object Time {
   val zero = Time(0)
 
   implicit def toTime(long: Long) = Time(long)
-  
-  implicit def toLong(time: Time) = time.milliseconds
 }
 
+/**
+ * Helper object that creates instance of [[spark.streaming.Time]] representing
+ * a given number of milliseconds.
+ */
 object Milliseconds {
   def apply(milliseconds: Long) = Time(milliseconds)
 }
 
+/**
+ * Helper object that creates instance of [[spark.streaming.Time]] representing
+ * a given number of seconds.
+ */
 object Seconds {
   def apply(seconds: Long) = Time(seconds * 1000)
-}  
+}
 
-object Minutes { 
+/**
+ * Helper object that creates instance of [[spark.streaming.Time]] representing
+ * a given number of minutes.
+ */
+object Minutes {
   def apply(minutes: Long) = Time(minutes * 60000)
 }
 
diff --git a/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
index 2e427dadf7..bc23d423d3 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
@@ -4,6 +4,7 @@ import spark.{RDD, Partitioner}
 import spark.rdd.CoGroupedRDD
 import spark.streaming.{Time, DStream}
 
+private[streaming]
 class CoGroupedDStream[K : ClassManifest](
     parents: Seq[DStream[(_, _)]],
     partitioner: Partitioner
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
index 8cdaff467b..cf72095324 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/FileInputDStream.scala
@@ -10,7 +10,7 @@ import org.apache.hadoop.mapreduce.{InputFormat => NewInputFormat}
 
 import scala.collection.mutable.HashSet
 
-
+private[streaming]
 class FileInputDStream[K: ClassManifest, V: ClassManifest, F <: NewInputFormat[K,V] : ClassManifest](
     @transient ssc_ : StreamingContext,
     directory: String,
diff --git a/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
index 7e988cadf4..ff73225e0f 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/FlumeInputDStream.scala
@@ -17,6 +17,7 @@ import java.net.InetSocketAddress
 import java.io.{ObjectInput, ObjectOutput, Externalizable}
 import java.nio.ByteBuffer
 
+private[streaming]
 class FlumeInputDStream[T: ClassManifest](
   @transient ssc_ : StreamingContext,
   host: String,
@@ -93,6 +94,7 @@ private[streaming] object SparkFlumeEvent {
 }
 
 /** A simple server that implements Flume's Avro protocol. */
+private[streaming]
 class FlumeEventServer(receiver : FlumeReceiver) extends AvroSourceProtocol {
   override def append(event : AvroFlumeEvent) : Status = {
     receiver.dataHandler += SparkFlumeEvent.fromAvroFlumeEvent(event)
@@ -108,12 +110,13 @@ class FlumeEventServer(receiver : FlumeReceiver) extends AvroSourceProtocol {
 
 /** A NetworkReceiver which listens for events using the
   * Flume Avro interface.*/
+private[streaming]
 class FlumeReceiver(
-      streamId: Int,
-      host: String,
-      port: Int,
-      storageLevel: StorageLevel
-      ) extends NetworkReceiver[SparkFlumeEvent](streamId) {
+    streamId: Int,
+    host: String,
+    port: Int,
+    storageLevel: StorageLevel
+  ) extends NetworkReceiver[SparkFlumeEvent](streamId) {
 
   lazy val dataHandler = new DataHandler(this, storageLevel)
 
diff --git a/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
index a46721af2f..175c75bcb9 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/KafkaInputDStream.scala
@@ -21,10 +21,12 @@ import scala.collection.JavaConversions._
 case class KafkaPartitionKey(brokerId: Int, topic: String, groupId: String, partId: Int)
 // NOT USED - Originally intended for fault-tolerance
 // Metadata for a Kafka Stream that it sent to the Master
+private[streaming]
 case class KafkaInputDStreamMetadata(timestamp: Long, data: Map[KafkaPartitionKey, Long])
 // NOT USED - Originally intended for fault-tolerance
 // Checkpoint data specific to a KafkaInputDstream
-case class KafkaDStreamCheckpointData(kafkaRdds: HashMap[Time, Any], 
+private[streaming]
+case class KafkaDStreamCheckpointData(kafkaRdds: HashMap[Time, Any],
   savedOffsets: Map[KafkaPartitionKey, Long]) extends DStreamCheckpointData(kafkaRdds)
 
 /**
@@ -39,6 +41,7 @@ case class KafkaDStreamCheckpointData(kafkaRdds: HashMap[Time, Any],
  * By default the value is pulled from zookeper.
  * @param storageLevel RDD storage level.
  */
+private[streaming]
 class KafkaInputDStream[T: ClassManifest](
     @transient ssc_ : StreamingContext,
     host: String,
@@ -98,6 +101,7 @@ class KafkaInputDStream[T: ClassManifest](
   }
 }
 
+private[streaming]
 class KafkaReceiver(streamId: Int, host: String, port: Int, groupId: String, 
   topics: Map[String, Int], initialOffsets: Map[KafkaPartitionKey, Long], 
   storageLevel: StorageLevel) extends NetworkReceiver[Any](streamId) {
diff --git a/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
index 996cc7dea8..aa2f31cea8 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/RawInputDStream.scala
@@ -17,6 +17,7 @@ import java.util.concurrent.ArrayBlockingQueue
  * data into Spark Streaming, though it requires the sender to batch data and serialize it
  * in the format that the system is configured with.
  */
+private[streaming]
 class RawInputDStream[T: ClassManifest](
     @transient ssc_ : StreamingContext,
     host: String,
@@ -29,6 +30,7 @@ class RawInputDStream[T: ClassManifest](
   }
 }
 
+private[streaming]
 class RawNetworkReceiver(streamId: Int, host: String, port: Int, storageLevel: StorageLevel)
   extends NetworkReceiver[Any](streamId) {
 
diff --git a/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
index 2686de14d2..d289ed2a3f 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/ReducedWindowedDStream.scala
@@ -11,6 +11,7 @@ import spark.storage.StorageLevel
 import scala.collection.mutable.ArrayBuffer
 import spark.streaming.{Interval, Time, DStream}
 
+private[streaming]
 class ReducedWindowedDStream[K: ClassManifest, V: ClassManifest](
     parent: DStream[(K, V)],
     reduceFunc: (V, V) => V,
diff --git a/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
index af5b73ae8d..cbe4372299 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/SocketInputDStream.scala
@@ -6,6 +6,7 @@ import spark.storage.StorageLevel
 import java.io._
 import java.net.Socket
 
+private[streaming]
 class SocketInputDStream[T: ClassManifest](
     @transient ssc_ : StreamingContext,
     host: String,
@@ -19,7 +20,7 @@ class SocketInputDStream[T: ClassManifest](
   }
 }
 
-
+private[streaming]
 class SocketReceiver[T: ClassManifest](
     streamId: Int,
     host: String,
@@ -50,7 +51,7 @@ class SocketReceiver[T: ClassManifest](
 
 }
 
-
+private[streaming]
 object SocketReceiver  {
 
   /**
diff --git a/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
index 6e190b5564..175b3060c1 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/StateDStream.scala
@@ -6,6 +6,7 @@ import spark.SparkContext._
 import spark.storage.StorageLevel
 import spark.streaming.{Time, DStream}
 
+private[streaming]
 class StateDStream[K: ClassManifest, V: ClassManifest, S <: AnyRef : ClassManifest](
     parent: DStream[(K, V)],
     updateFunc: (Iterator[(K, Seq[V], Option[S])]) => Iterator[(K, S)],
diff --git a/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
index f1efb2ae72..3bf4c2ecea 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/UnionDStream.scala
@@ -5,6 +5,7 @@ import spark.RDD
 import collection.mutable.ArrayBuffer
 import spark.rdd.UnionRDD
 
+private[streaming]
 class UnionDStream[T: ClassManifest](parents: Array[DStream[T]])
   extends DStream[T](parents.head.ssc) {
 
diff --git a/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala b/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
index 4b2621c497..7718794cbf 100644
--- a/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
+++ b/streaming/src/main/scala/spark/streaming/dstream/WindowedDStream.scala
@@ -5,7 +5,7 @@ import spark.rdd.UnionRDD
 import spark.storage.StorageLevel
 import spark.streaming.{Interval, Time, DStream}
 
-
+private[streaming]
 class WindowedDStream[T: ClassManifest](
     parent: DStream[T],
     _windowTime: Time,
diff --git a/streaming/src/main/scala/spark/streaming/util/Clock.scala b/streaming/src/main/scala/spark/streaming/util/Clock.scala
index ed087e4ea8..974651f9f6 100644
--- a/streaming/src/main/scala/spark/streaming/util/Clock.scala
+++ b/streaming/src/main/scala/spark/streaming/util/Clock.scala
@@ -1,13 +1,12 @@
 package spark.streaming.util
 
-import spark.streaming._
-
-trait Clock {  
+private[streaming]
+trait Clock {
   def currentTime(): Long 
   def waitTillTime(targetTime: Long): Long
 }
 
-
+private[streaming]
 class SystemClock() extends Clock {
   
   val minPollTime = 25L
@@ -54,6 +53,7 @@ class SystemClock() extends Clock {
   }
 }
 
+private[streaming]
 class ManualClock() extends Clock {
   
   var time = 0L
diff --git a/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala b/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
index dc55fd902b..2e7f4169c9 100644
--- a/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
+++ b/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
@@ -1,5 +1,6 @@
 package spark.streaming.util
 
+private[streaming]
 class RecurringTimer(val clock: Clock, val period: Long, val callback: (Long) => Unit) {
   
   val minPollTime = 25L
-- 
cgit v1.2.3


From 02497f0cd49a24ebc8b92d3471de250319fe56cd Mon Sep 17 00:00:00 2001
From: Tathagata Das <tathagata.das1565@gmail.com>
Date: Tue, 1 Jan 2013 12:21:32 -0800
Subject: Updated Streaming Programming Guide.

---
 docs/_layouts/global.html                          |  12 +-
 docs/api.md                                        |   5 +-
 docs/configuration.md                              |  11 ++
 docs/streaming-programming-guide.md                | 167 +++++++++++++++++++--
 .../spark/streaming/util/RecurringTimer.scala      |   1 +
 5 files changed, 179 insertions(+), 17 deletions(-)

(limited to 'streaming')

diff --git a/docs/_layouts/global.html b/docs/_layouts/global.html
index d656b3e3de..a8be52f23e 100755
--- a/docs/_layouts/global.html
+++ b/docs/_layouts/global.html
@@ -47,11 +47,19 @@
                                 <li><a href="quick-start.html">Quick Start</a></li>
                                 <li><a href="scala-programming-guide.html">Scala</a></li>
                                 <li><a href="java-programming-guide.html">Java</a></li>
-                                <li><a href="streaming-programming-guide.html">Spark Streaming (Alpha)</a></li>
+                                <li><a href="streaming-programming-guide.html">Spark Streaming</a></li>
                             </ul>
                         </li>
                         
-                        <li><a href="api/core/index.html">API (Scaladoc)</a></li>
+                        <li class="dropdown">
+                            <a href="#" class="dropdown-toggle" data-toggle="dropdown">API (Scaladoc)<b class="caret"></b></a>
+                            <ul class="dropdown-menu">
+                                <li><a href="api/core/index.html">Spark</a></li>
+                                <li><a href="api/examples/index.html">Spark Examples</a></li>
+                                <li><a href="api/streaming/index.html">Spark Streaming</a></li>
+                                <li><a href="api/bagel/index.html">Bagel</a></li>
+                            </ul>
+                        </li>
 
                         <li class="dropdown">
                             <a href="#" class="dropdown-toggle" data-toggle="dropdown">Deploying<b class="caret"></b></a>
diff --git a/docs/api.md b/docs/api.md
index 43548b223c..3a13e30f82 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -5,6 +5,7 @@ title: Spark API documentation (Scaladoc)
 
 Here you can find links to the Scaladoc generated for the Spark sbt subprojects.  If the following links don't work, try running `sbt/sbt doc` from the Spark project home directory.
 
-- [Core](api/core/index.html)
-- [Examples](api/examples/index.html)
+- [Spark](api/core/index.html)
+- [Spark Examples](api/examples/index.html)
+- [Spark Streaming](api/streaming/index.html)
 - [Bagel](api/bagel/index.html)
diff --git a/docs/configuration.md b/docs/configuration.md
index d8317ea97c..87cb4a6797 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -219,6 +219,17 @@ Apart from these, the following properties are also available, and may be useful
     Port for the master to listen on.
   </td>
 </tr>
+<tr>
+  <td>spark.cleaner.delay</td>
+  <td>(disable)</td>
+  <td>
+    Duration (minutes) of how long Spark will remember any metadata (stages generated, tasks generated, etc.).
+    Periodic cleanups will ensure that metadata older than this duration will be forgetten. This is
+    useful for running Spark for many hours / days (for example, running 24/7 in case of Spark Streaming
+    applications). Note that any RDD that persists in memory for more than this duration will be cleared as well.
+  </td>
+</tr>
+
 </table>
 
 # Configuring Logging
diff --git a/docs/streaming-programming-guide.md b/docs/streaming-programming-guide.md
index 7c421ac70f..fc2ea2ef79 100644
--- a/docs/streaming-programming-guide.md
+++ b/docs/streaming-programming-guide.md
@@ -1,8 +1,9 @@
 ---
 layout: global
-title: Streaming (Alpha) Programming Guide
+title: Spark Streaming Programming Guide
 ---
 
+* This will become a table of contents (this text will be scraped).
 {:toc}
 
 # Overview
@@ -13,33 +14,38 @@ A Spark Streaming application is very similar to a Spark application; it consist
 This guide shows some how to start programming with DStreams. 
 
 # Initializing Spark Streaming
-The first thing a Spark Streaming program must do is create a `StreamingContext` object, which tells Spark how to access a cluster. A `StreamingContext` can be created from an existing `SparkContext`, or directly:
+The first thing a Spark Streaming program must do is create a `StreamingContext` object, which tells Spark how to access a cluster. A `StreamingContext` can be created by using
 
 {% highlight scala %}
-import spark.SparkContext
-import SparkContext._
+new StreamingContext(master, jobName, batchDuration)
+{% endhighlight %}
+
+The `master` parameter is either the [Mesos master URL](running-on-mesos.html) (for running on a cluster)or the special "local" string (for local mode) that is used to create a Spark Context. For more information about this please refer to the [Spark programming guide](scala-programming-guide.html). The `jobName` is the name of the streaming job, which is the same as the jobName used in SparkContext. It is used to identify this job in the Mesos web UI. The `batchDuration` is the size of the batches (as explained earlier). This must be set carefully such the cluster can keep up with the processing of the data streams. Starting with something conservative like 5 seconds maybe a good start. See [Performance Tuning](#setting-the-right-batch-size) section for a detailed discussion.
 
-new StreamingContext(master, frameworkName, batchDuration)
+This constructor creates a SparkContext object using the given `master` and `jobName` parameters. However, if you already have a SparkContext or you need to create a custom SparkContext by specifying list of JARs, then a StreamingContext can be created from the existing SparkContext, by using
+{% highlight scala %}
 new StreamingContext(sparkContext, batchDuration)
 {% endhighlight %}
 
-The `master` parameter is either the [Mesos master URL](running-on-mesos.html) (for running on a cluster)or the special "local" string (for local mode) that is used to create a Spark Context. For more information about this please refer to the [Spark programming guide](scala-programming-guide.html).
 
 
-# Creating Input Sources - InputDStreams
+# Attaching Input Sources - InputDStreams
 The StreamingContext is used to creating InputDStreams from input sources:
 
 {% highlight scala %}
-context.neworkStream(host, port) // Creates a stream that uses a TCP socket to read data from <host>:<port>
-context.flumeStream(host, port)  // Creates a stream populated by a Flume flow
+// Assuming ssc is the StreamingContext
+ssc.networkStream(hostname, port)    // Creates a stream that uses a TCP socket to read data from hostname:port
+ssc.textFileStream(directory)   // Creates a stream by monitoring and processing new files in a HDFS directory
 {% endhighlight %}
 
-A complete list of input sources is available in the [DStream API doc](api/streaming/index.html#spark.streaming.StreamingContext). 
+A complete list of input sources is available in the [StreamingContext API documentation](api/streaming/index.html#spark.streaming.StreamingContext). Data received from these sources can be processed using DStream operations, which are explained next.
+
 
-## DStream Operations
+
+# DStream Operations
 Once an input stream has been created, you can transform it using _stream operators_. Most of these operators return new DStreams which you can further transform. Eventually, you'll need to call an _output operator_, which forces evaluation of the stream by writing data out to an external source.
 
-### Transformations
+## Transformations
 
 DStreams support many of the transformations available on normal Spark RDD's:
 
@@ -132,7 +138,7 @@ Spark Streaming features windowed computations, which allow you to report statis
 </table>
 
 
-### Output Operators
+## Output Operations
 When an output operator is called, it triggers the computation of a stream. Currently the following output operators are defined:
 
 <table class="table">
@@ -165,3 +171,138 @@ When an output operator is called, it triggers the computation of a stream. Curr
 
 </table>
 
+## DStream Persistence
+Similar to RDDs, DStreams also allow developers to persist the stream's data in memory. That is, using `persist()` method on a DStream would automatically persist every RDD of that DStream in memory. This is useful if the data in the DStream will be computed multiple times (e.g., multiple DStream operations on the same data). For window-based operations like `reduceByWindow` and `reduceByKeyAndWindow` and state-based operations like `updateStateByKey`, this is implicitly true. Hence, DStreams generated by window-based operations are automatically persisted in memory, without the developer calling `persist()`.
+
+Note that, unlike RDDs, the default persistence level of DStreams keeps the data serialized in memory. This is further discussed in the [Performance Tuning](#memory-tuning) section. More information on different persistence levels can be found in [Spark Programming Guide](scala-programming-guide.html#rdd-persistence).
+
+# Starting the Streaming computation
+All the above DStream operations are completely lazy, that is, the operations will start executing only after the context is started by using
+{% highlight scala %}
+ssc.start()
+{% endhighlight %}
+
+Conversely, the computation can be stopped by using
+{% highlight scala %}
+ssc.stop()
+{% endhighlight %}
+
+# Example - WordCountNetwork.scala
+A good example to start off is the spark.streaming.examples.WordCountNetwork. This example counts the words received from a network server every second. Given below is the relevant sections of the source code. You can find the full source code in <Spark repo>/streaming/src/main/scala/spark/streaming/examples/WordCountNetwork.scala.
+
+{% highlight scala %}
+import spark.streaming.{Seconds, StreamingContext}
+import spark.streaming.StreamingContext._
+...
+
+// Create the context and set up a network input stream to receive from a host:port
+val ssc = new StreamingContext(args(0), "WordCountNetwork", Seconds(1))
+val lines = ssc.networkTextStream(args(1), args(2).toInt)
+
+// Split the lines into words, count them, and print some of the counts on the master
+val words = lines.flatMap(_.split(" "))
+val wordCounts = words.map(x => (x, 1)).reduceByKey(_ + _)
+wordCounts.print()
+
+// Start the computation
+ssc.start()
+{% endhighlight %}
+
+To run this example on your local machine, you need to first run a Netcat server by using
+
+{% highlight bash %}
+$ nc -lk 9999
+{% endhighlight %}
+
+Then, in a different terminal, you can start WordCountNetwork by using
+
+{% highlight bash %}
+$ ./run spark.streaming.examples.WordCountNetwork local[2] localhost 9999
+{% endhighlight %}
+
+This will make WordCountNetwork connect to the netcat server. Any lines typed in the terminal running the netcat server will be counted and printed on screen.
+
+<table>
+<td>
+{% highlight bash %}
+# TERMINAL 1
+# RUNNING NETCAT
+
+$ nc -lk 9999
+hello world
+
+
+
+
+
+...
+{% endhighlight %}
+</td>
+<td>
+{% highlight bash %}
+# TERMINAL 2: RUNNING WordCountNetwork
+...
+2012-12-31 18:47:10,446 INFO SparkContext: Job finished: run at ThreadPoolExecutor.java:886, took 0.038817 s
+-------------------------------------------
+Time: 1357008430000 ms
+-------------------------------------------
+(hello,1)
+(world,1)
+
+2012-12-31 18:47:10,447 INFO JobManager: Total delay: 0.44700 s for job 8 (execution: 0.44000 s)
+...
+{% endhighlight %}
+</td>
+</table>
+
+
+
+# Performance Tuning
+Getting the best performance of a Spark Streaming application on a cluster requires a bit of tuning. This section explains a number of the parameters and configurations that can tuned to improve the performance of you application. At a high level, you need to consider two things:
+<ol>
+<li>Reducing the processing time of each batch of data by efficiently using cluster resources.</li>
+<li>Setting the right batch size such that the data processing can keep up with the data ingestion.</li>
+</ol>
+
+## Reducing the Processing Time of each Batch
+There are a number of optimizations that can be done in Spark to minimize the processing time of each batch. These have been discussed in detail in [Tuning Guide](tuning.html). This section highlights some of the most important ones.
+
+### Level of Parallelism
+Cluster resources maybe underutilized if the number of parallel tasks used in any stage of the computation is not high enough. For example, for distributed reduce operations like `reduceByKey` and `reduceByKeyAndWindow`, the default number of parallel tasks is 8. You can pass the level of parallelism as an argument (see the [`spark.PairDStreamFunctions`](api/streaming/index.html#spark.PairDStreamFunctions) documentation), or set the system property `spark.default.parallelism` to change the default.
+
+### Data Serialization
+The overhead of data serialization can be significant, especially when sub-second batch sizes are to be achieved. There are two aspects to it.
+* Serialization of RDD data in Spark: Please refer to the detailed discussion on data serialization in the [Tuning Guide](tuning.html). However, note that unlike Spark, by default RDDs are persisted as serialized byte arrays to minimize pauses related to GC.
+* Serialization of input data: To ingest external data into Spark, data received as bytes (say, from the network) needs to deserialized from bytes and re-serialized into Spark's serialization format. Hence, the deserialization overhead of input data may be a bottleneck.
+
+### Task Launching Overheads
+If the number of tasks launched per second is high (say, 50 or more per second), then the overhead of sending out tasks to the slaves maybe significant and will make it hard to achieve sub-second latencies. The overhead can be reduced by the following changes:
+* Task Serialization: Using Kryo serialization for serializing tasks can reduced the task sizes, and therefore reduce the time taken to send them to the slaves.
+* Execution mode: Running Spark in Standalone mode or coarse-grained Mesos mode leads to better task launch times than the fine-grained Mesos mode. Please refer to the [Running on Mesos guide](running-on-mesos.html) for more details.
+These changes may reduce batch processing time by 100s of milliseconds, thus allowing sub-second batch size to be viable.
+
+## Setting the Right Batch Size
+For a Spark Streaming application running on a cluster to be stable, the processing of the data streams must keep up with the rate of ingestion of the data streams. Depending on the type of computation, the batch size used may have significant impact on the rate of ingestion that can be sustained by the Spark Streaming application on a fixed cluster resources. For example, let us consider the earlier WordCountNetwork example. For a particular data rate, the system may be able to keep up with reporting word counts every 2 seconds (i.e., batch size of 2 seconds), but not every 500 milliseconds.
+
+A good approach to figure out the right batch size for your application is to test it with a conservative batch size (say, 5-10 seconds) and a low data rate. To verify whether the system is able to keep up with data rate, you can check the value of the end-to-end delay experienced by each processed batch (in the Spark master logs, find the line having the phrase "Total delay"). If the delay is maintained to be less than the batch size, then system is stable. Otherwise, if the delay is continuously increasing, it means that the system is unable to keep up and it therefore unstable. Once you have an idea of a stable configuration, you can try increasing the data rate and/or reducing the batch size. Note that momentary increase in the delay due to temporary data rate increases maybe fine as long as the delay reduces back to a low value (i.e., less than batch size).
+
+## 24/7 Operation
+By default, Spark does not forget any of the metadata (RDDs generated, stages processed, etc.). But for a Spark Streaming application to operate 24/7, it is necessary for Spark to do periodic cleanup of it metadata. This can be enabled by setting the Java system property `spark.cleaner.delay` to the number of minutes you want any metadata to persist. For example, setting `spark.cleaner.delay` to 10 would cause Spark periodically cleanup all metadata and persisted RDDs that are older than 10 minutes. Note, that this property needs to be set before the SparkContext is created.
+
+This value is closely tied with any window operation that is being used. Any window operation would require the input data to be persisted in memory for at least the duration of the window. Hence it is necessary to set the delay to at least the value of the largest window operation used in the Spark Streaming application. If this delay is set too low, the application will throw an exception saying so.
+
+## Memory Tuning
+Tuning the memory usage and GC behavior of Spark applications have been discussed in great detail in the [Tuning Guide](tuning.html). It is recommended that you read that. In this section, we highlight a few customizations that are strongly recommended to minimize GC related pauses in Spark Streaming applications and achieving more consistent batch processing times.
+
+* <b>Default persistence level of DStreams</b>: Unlike RDDs, the default persistence level of DStreams serializes the data in memory (that is, [StorageLevel.MEMORY_ONLY_SER](api/core/index.html#spark.storage.StorageLevel$) for DStream compared to [StorageLevel.MEMORY_ONLY](api/core/index.html#spark.storage.StorageLevel$) for RDDs). Even though keeping the data serialized incurs a higher serialization overheads, it significantly reduces GC pauses.
+
+* <b>Concurrent garbage collector</b>: Using the concurrent mark-and-sweep GC further minimizes the variability of GC pauses. Even though concurrent GC is known to reduce the overall processing throughput of the system, its use is still recommended to achieve more consistent batch processing times.
+
+# Master Fault-tolerance (Alpha)
+TODO
+
+* Checkpointing of DStream graph
+
+* Recovery from master faults
+
+* Current state and future directions
\ No newline at end of file
diff --git a/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala b/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
index 2e7f4169c9..db715cc295 100644
--- a/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
+++ b/streaming/src/main/scala/spark/streaming/util/RecurringTimer.scala
@@ -54,6 +54,7 @@ class RecurringTimer(val clock: Clock, val period: Long, val callback: (Long) =>
   }
 }
 
+private[streaming]
 object RecurringTimer {
   
   def main(args: Array[String]) {
-- 
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