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Posted to commits@spark.apache.org by ma...@apache.org on 2013/09/01 23:59:22 UTC

[38/69] [abbrv] [partial] Initial work to rename package to org.apache.spark

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/metrics/source/Source.scala
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diff --git a/core/src/main/scala/org/apache/spark/metrics/source/Source.scala b/core/src/main/scala/org/apache/spark/metrics/source/Source.scala
new file mode 100644
index 0000000..3fee55c
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/metrics/source/Source.scala
@@ -0,0 +1,25 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.metrics.source
+
+import com.codahale.metrics.MetricRegistry
+
+trait Source {
+  def sourceName: String
+  def metricRegistry: MetricRegistry
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/BufferMessage.scala
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diff --git a/core/src/main/scala/org/apache/spark/network/BufferMessage.scala b/core/src/main/scala/org/apache/spark/network/BufferMessage.scala
new file mode 100644
index 0000000..f736bb3
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/BufferMessage.scala
@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.nio.ByteBuffer
+
+import scala.collection.mutable.ArrayBuffer
+
+import org.apache.spark.storage.BlockManager
+
+
+private[spark]
+class BufferMessage(id_ : Int, val buffers: ArrayBuffer[ByteBuffer], var ackId: Int)
+  extends Message(Message.BUFFER_MESSAGE, id_) {
+
+  val initialSize = currentSize()
+  var gotChunkForSendingOnce = false
+
+  def size = initialSize
+
+  def currentSize() = {
+    if (buffers == null || buffers.isEmpty) {
+      0
+    } else {
+      buffers.map(_.remaining).reduceLeft(_ + _)
+    }
+  }
+
+  def getChunkForSending(maxChunkSize: Int): Option[MessageChunk] = {
+    if (maxChunkSize <= 0) {
+      throw new Exception("Max chunk size is " + maxChunkSize)
+    }
+
+    if (size == 0 && gotChunkForSendingOnce == false) {
+      val newChunk = new MessageChunk(
+        new MessageChunkHeader(typ, id, 0, 0, ackId, senderAddress), null)
+      gotChunkForSendingOnce = true
+      return Some(newChunk)
+    }
+
+    while(!buffers.isEmpty) {
+      val buffer = buffers(0)
+      if (buffer.remaining == 0) {
+        BlockManager.dispose(buffer)
+        buffers -= buffer
+      } else {
+        val newBuffer = if (buffer.remaining <= maxChunkSize) {
+          buffer.duplicate()
+        } else {
+          buffer.slice().limit(maxChunkSize).asInstanceOf[ByteBuffer]
+        }
+        buffer.position(buffer.position + newBuffer.remaining)
+        val newChunk = new MessageChunk(new MessageChunkHeader(
+            typ, id, size, newBuffer.remaining, ackId, senderAddress), newBuffer)
+        gotChunkForSendingOnce = true
+        return Some(newChunk)
+      }
+    }
+    None
+  }
+
+  def getChunkForReceiving(chunkSize: Int): Option[MessageChunk] = {
+    // STRONG ASSUMPTION: BufferMessage created when receiving data has ONLY ONE data buffer
+    if (buffers.size > 1) {
+      throw new Exception("Attempting to get chunk from message with multiple data buffers")
+    }
+    val buffer = buffers(0)
+    if (buffer.remaining > 0) {
+      if (buffer.remaining < chunkSize) {
+        throw new Exception("Not enough space in data buffer for receiving chunk")
+      }
+      val newBuffer = buffer.slice().limit(chunkSize).asInstanceOf[ByteBuffer]
+      buffer.position(buffer.position + newBuffer.remaining)
+      val newChunk = new MessageChunk(new MessageChunkHeader(
+          typ, id, size, newBuffer.remaining, ackId, senderAddress), newBuffer)
+      return Some(newChunk)
+    }
+    None
+  }
+
+  def flip() {
+    buffers.foreach(_.flip)
+  }
+
+  def hasAckId() = (ackId != 0)
+
+  def isCompletelyReceived() = !buffers(0).hasRemaining
+
+  override def toString = {
+    if (hasAckId) {
+      "BufferAckMessage(aid = " + ackId + ", id = " + id + ", size = " + size + ")"
+    } else {
+      "BufferMessage(id = " + id + ", size = " + size + ")"
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/Connection.scala
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diff --git a/core/src/main/scala/org/apache/spark/network/Connection.scala b/core/src/main/scala/org/apache/spark/network/Connection.scala
new file mode 100644
index 0000000..95cb020
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/Connection.scala
@@ -0,0 +1,586 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import org.apache.spark._
+
+import scala.collection.mutable.{HashMap, Queue, ArrayBuffer}
+
+import java.io._
+import java.nio._
+import java.nio.channels._
+import java.nio.channels.spi._
+import java.net._
+
+
+private[spark]
+abstract class Connection(val channel: SocketChannel, val selector: Selector,
+    val socketRemoteConnectionManagerId: ConnectionManagerId)
+  extends Logging {
+
+  def this(channel_ : SocketChannel, selector_ : Selector) = {
+    this(channel_, selector_,
+      ConnectionManagerId.fromSocketAddress(
+        channel_.socket.getRemoteSocketAddress().asInstanceOf[InetSocketAddress]))
+  }
+
+  channel.configureBlocking(false)
+  channel.socket.setTcpNoDelay(true)
+  channel.socket.setReuseAddress(true)
+  channel.socket.setKeepAlive(true)
+  /*channel.socket.setReceiveBufferSize(32768) */
+
+  @volatile private var closed = false
+  var onCloseCallback: Connection => Unit = null
+  var onExceptionCallback: (Connection, Exception) => Unit = null
+  var onKeyInterestChangeCallback: (Connection, Int) => Unit = null
+
+  val remoteAddress = getRemoteAddress()
+
+  def resetForceReregister(): Boolean
+
+  // Read channels typically do not register for write and write does not for read
+  // Now, we do have write registering for read too (temporarily), but this is to detect
+  // channel close NOT to actually read/consume data on it !
+  // How does this work if/when we move to SSL ?
+
+  // What is the interest to register with selector for when we want this connection to be selected
+  def registerInterest()
+
+  // What is the interest to register with selector for when we want this connection to
+  // be de-selected
+  // Traditionally, 0 - but in our case, for example, for close-detection on SendingConnection hack,
+  // it will be SelectionKey.OP_READ (until we fix it properly)
+  def unregisterInterest()
+
+  // On receiving a read event, should we change the interest for this channel or not ?
+  // Will be true for ReceivingConnection, false for SendingConnection.
+  def changeInterestForRead(): Boolean
+
+  // On receiving a write event, should we change the interest for this channel or not ?
+  // Will be false for ReceivingConnection, true for SendingConnection.
+  // Actually, for now, should not get triggered for ReceivingConnection
+  def changeInterestForWrite(): Boolean
+
+  def getRemoteConnectionManagerId(): ConnectionManagerId = {
+    socketRemoteConnectionManagerId
+  }
+
+  def key() = channel.keyFor(selector)
+
+  def getRemoteAddress() = channel.socket.getRemoteSocketAddress().asInstanceOf[InetSocketAddress]
+
+  // Returns whether we have to register for further reads or not.
+  def read(): Boolean = {
+    throw new UnsupportedOperationException(
+      "Cannot read on connection of type " + this.getClass.toString)
+  }
+
+  // Returns whether we have to register for further writes or not.
+  def write(): Boolean = {
+    throw new UnsupportedOperationException(
+      "Cannot write on connection of type " + this.getClass.toString)
+  }
+
+  def close() {
+    closed = true
+    val k = key()
+    if (k != null) {
+      k.cancel()
+    }
+    channel.close()
+    callOnCloseCallback()
+  }
+
+  protected def isClosed: Boolean = closed
+
+  def onClose(callback: Connection => Unit) {
+    onCloseCallback = callback
+  }
+
+  def onException(callback: (Connection, Exception) => Unit) {
+    onExceptionCallback = callback
+  }
+
+  def onKeyInterestChange(callback: (Connection, Int) => Unit) {
+    onKeyInterestChangeCallback = callback
+  }
+
+  def callOnExceptionCallback(e: Exception) {
+    if (onExceptionCallback != null) {
+      onExceptionCallback(this, e)
+    } else {
+      logError("Error in connection to " + getRemoteConnectionManagerId() +
+        " and OnExceptionCallback not registered", e)
+    }
+  }
+
+  def callOnCloseCallback() {
+    if (onCloseCallback != null) {
+      onCloseCallback(this)
+    } else {
+      logWarning("Connection to " + getRemoteConnectionManagerId() +
+        " closed and OnExceptionCallback not registered")
+    }
+
+  }
+
+  def changeConnectionKeyInterest(ops: Int) {
+    if (onKeyInterestChangeCallback != null) {
+      onKeyInterestChangeCallback(this, ops)
+    } else {
+      throw new Exception("OnKeyInterestChangeCallback not registered")
+    }
+  }
+
+  def printRemainingBuffer(buffer: ByteBuffer) {
+    val bytes = new Array[Byte](buffer.remaining)
+    val curPosition = buffer.position
+    buffer.get(bytes)
+    bytes.foreach(x => print(x + " "))
+    buffer.position(curPosition)
+    print(" (" + bytes.size + ")")
+  }
+
+  def printBuffer(buffer: ByteBuffer, position: Int, length: Int) {
+    val bytes = new Array[Byte](length)
+    val curPosition = buffer.position
+    buffer.position(position)
+    buffer.get(bytes)
+    bytes.foreach(x => print(x + " "))
+    print(" (" + position + ", " + length + ")")
+    buffer.position(curPosition)
+  }
+}
+
+
+private[spark]
+class SendingConnection(val address: InetSocketAddress, selector_ : Selector,
+    remoteId_ : ConnectionManagerId)
+  extends Connection(SocketChannel.open, selector_, remoteId_) {
+
+  private class Outbox(fair: Int = 0) {
+    val messages = new Queue[Message]()
+    val defaultChunkSize = 65536  //32768 //16384
+    var nextMessageToBeUsed = 0
+
+    def addMessage(message: Message) {
+      messages.synchronized{
+        /*messages += message*/
+        messages.enqueue(message)
+        logDebug("Added [" + message + "] to outbox for sending to " +
+          "[" + getRemoteConnectionManagerId() + "]")
+      }
+    }
+
+    def getChunk(): Option[MessageChunk] = {
+      fair match {
+        case 0 => getChunkFIFO()
+        case 1 => getChunkRR()
+        case _ => throw new Exception("Unexpected fairness policy in outbox")
+      }
+    }
+
+    private def getChunkFIFO(): Option[MessageChunk] = {
+      /*logInfo("Using FIFO")*/
+      messages.synchronized {
+        while (!messages.isEmpty) {
+          val message = messages(0)
+          val chunk = message.getChunkForSending(defaultChunkSize)
+          if (chunk.isDefined) {
+            messages += message  // this is probably incorrect, it wont work as fifo
+            if (!message.started) {
+              logDebug("Starting to send [" + message + "]")
+              message.started = true
+              message.startTime = System.currentTimeMillis
+            }
+            return chunk
+          } else {
+            /*logInfo("Finished sending [" + message + "] to [" + getRemoteConnectionManagerId() + "]")*/
+            message.finishTime = System.currentTimeMillis
+            logDebug("Finished sending [" + message + "] to [" + getRemoteConnectionManagerId() +
+              "] in "  + message.timeTaken )
+          }
+        }
+      }
+      None
+    }
+
+    private def getChunkRR(): Option[MessageChunk] = {
+      messages.synchronized {
+        while (!messages.isEmpty) {
+          /*nextMessageToBeUsed = nextMessageToBeUsed % messages.size */
+          /*val message = messages(nextMessageToBeUsed)*/
+          val message = messages.dequeue
+          val chunk = message.getChunkForSending(defaultChunkSize)
+          if (chunk.isDefined) {
+            messages.enqueue(message)
+            nextMessageToBeUsed = nextMessageToBeUsed + 1
+            if (!message.started) {
+              logDebug(
+                "Starting to send [" + message + "] to [" + getRemoteConnectionManagerId() + "]")
+              message.started = true
+              message.startTime = System.currentTimeMillis
+            }
+            logTrace(
+              "Sending chunk from [" + message+ "] to [" + getRemoteConnectionManagerId() + "]")
+            return chunk
+          } else {
+            message.finishTime = System.currentTimeMillis
+            logDebug("Finished sending [" + message + "] to [" + getRemoteConnectionManagerId() +
+              "] in "  + message.timeTaken )
+          }
+        }
+      }
+      None
+    }
+  }
+
+  // outbox is used as a lock - ensure that it is always used as a leaf (since methods which 
+  // lock it are invoked in context of other locks)
+  private val outbox = new Outbox(1)
+  /*
+    This is orthogonal to whether we have pending bytes to write or not - and satisfies a slightly 
+    different purpose. This flag is to see if we need to force reregister for write even when we 
+    do not have any pending bytes to write to socket.
+    This can happen due to a race between adding pending buffers, and checking for existing of 
+    data as detailed in https://github.com/mesos/spark/pull/791
+   */
+  private var needForceReregister = false
+  val currentBuffers = new ArrayBuffer[ByteBuffer]()
+
+  /*channel.socket.setSendBufferSize(256 * 1024)*/
+
+  override def getRemoteAddress() = address
+
+  val DEFAULT_INTEREST = SelectionKey.OP_READ
+
+  override def registerInterest() {
+    // Registering read too - does not really help in most cases, but for some
+    // it does - so let us keep it for now.
+    changeConnectionKeyInterest(SelectionKey.OP_WRITE | DEFAULT_INTEREST)
+  }
+
+  override def unregisterInterest() {
+    changeConnectionKeyInterest(DEFAULT_INTEREST)
+  }
+
+  def send(message: Message) {
+    outbox.synchronized {
+      outbox.addMessage(message)
+      needForceReregister = true
+    }
+    if (channel.isConnected) {
+      registerInterest()
+    }
+  }
+
+  // return previous value after resetting it.
+  def resetForceReregister(): Boolean = {
+    outbox.synchronized {
+      val result = needForceReregister
+      needForceReregister = false
+      result
+    }
+  }
+
+  // MUST be called within the selector loop
+  def connect() {
+    try{
+      channel.register(selector, SelectionKey.OP_CONNECT)
+      channel.connect(address)
+      logInfo("Initiating connection to [" + address + "]")
+    } catch {
+      case e: Exception => {
+        logError("Error connecting to " + address, e)
+        callOnExceptionCallback(e)
+      }
+    }
+  }
+
+  def finishConnect(force: Boolean): Boolean = {
+    try {
+      // Typically, this should finish immediately since it was triggered by a connect
+      // selection - though need not necessarily always complete successfully.
+      val connected = channel.finishConnect
+      if (!force && !connected) {
+        logInfo(
+          "finish connect failed [" + address + "], " + outbox.messages.size + " messages pending")
+        return false
+      }
+
+      // Fallback to previous behavior - assume finishConnect completed
+      // This will happen only when finishConnect failed for some repeated number of times
+      // (10 or so)
+      // Is highly unlikely unless there was an unclean close of socket, etc
+      registerInterest()
+      logInfo("Connected to [" + address + "], " + outbox.messages.size + " messages pending")
+      return true
+    } catch {
+      case e: Exception => {
+        logWarning("Error finishing connection to " + address, e)
+        callOnExceptionCallback(e)
+        // ignore
+        return true
+      }
+    }
+  }
+
+  override def write(): Boolean = {
+    try {
+      while (true) {
+        if (currentBuffers.size == 0) {
+          outbox.synchronized {
+            outbox.getChunk() match {
+              case Some(chunk) => {
+                val buffers = chunk.buffers
+                // If we have 'seen' pending messages, then reset flag - since we handle that as normal 
+                // registering of event (below)
+                if (needForceReregister && buffers.exists(_.remaining() > 0)) resetForceReregister()
+                currentBuffers ++= buffers
+              }
+              case None => {
+                // changeConnectionKeyInterest(0)
+                /*key.interestOps(0)*/
+                return false
+              }
+            }
+          }
+        }
+
+        if (currentBuffers.size > 0) {
+          val buffer = currentBuffers(0)
+          val remainingBytes = buffer.remaining
+          val writtenBytes = channel.write(buffer)
+          if (buffer.remaining == 0) {
+            currentBuffers -= buffer
+          }
+          if (writtenBytes < remainingBytes) {
+            // re-register for write.
+            return true
+          }
+        }
+      }
+    } catch {
+      case e: Exception => {
+        logWarning("Error writing in connection to " + getRemoteConnectionManagerId(), e)
+        callOnExceptionCallback(e)
+        close()
+        return false
+      }
+    }
+    // should not happen - to keep scala compiler happy
+    return true
+  }
+
+  // This is a hack to determine if remote socket was closed or not.
+  // SendingConnection DOES NOT expect to receive any data - if it does, it is an error
+  // For a bunch of cases, read will return -1 in case remote socket is closed : hence we
+  // register for reads to determine that.
+  override def read(): Boolean = {
+    // We don't expect the other side to send anything; so, we just read to detect an error or EOF.
+    try {
+      val length = channel.read(ByteBuffer.allocate(1))
+      if (length == -1) { // EOF
+        close()
+      } else if (length > 0) {
+        logWarning(
+          "Unexpected data read from SendingConnection to " + getRemoteConnectionManagerId())
+      }
+    } catch {
+      case e: Exception =>
+        logError("Exception while reading SendingConnection to " + getRemoteConnectionManagerId(), e)
+        callOnExceptionCallback(e)
+        close()
+    }
+
+    false
+  }
+
+  override def changeInterestForRead(): Boolean = false
+
+  override def changeInterestForWrite(): Boolean = ! isClosed
+}
+
+
+// Must be created within selector loop - else deadlock
+private[spark] class ReceivingConnection(channel_ : SocketChannel, selector_ : Selector)
+  extends Connection(channel_, selector_) {
+
+  class Inbox() {
+    val messages = new HashMap[Int, BufferMessage]()
+
+    def getChunk(header: MessageChunkHeader): Option[MessageChunk] = {
+
+      def createNewMessage: BufferMessage = {
+        val newMessage = Message.create(header).asInstanceOf[BufferMessage]
+        newMessage.started = true
+        newMessage.startTime = System.currentTimeMillis
+        logDebug(
+          "Starting to receive [" + newMessage + "] from [" + getRemoteConnectionManagerId() + "]")
+        messages += ((newMessage.id, newMessage))
+        newMessage
+      }
+
+      val message = messages.getOrElseUpdate(header.id, createNewMessage)
+      logTrace(
+        "Receiving chunk of [" + message + "] from [" + getRemoteConnectionManagerId() + "]")
+      message.getChunkForReceiving(header.chunkSize)
+    }
+
+    def getMessageForChunk(chunk: MessageChunk): Option[BufferMessage] = {
+      messages.get(chunk.header.id)
+    }
+
+    def removeMessage(message: Message) {
+      messages -= message.id
+    }
+  }
+
+  @volatile private var inferredRemoteManagerId: ConnectionManagerId = null
+
+  override def getRemoteConnectionManagerId(): ConnectionManagerId = {
+    val currId = inferredRemoteManagerId
+    if (currId != null) currId else super.getRemoteConnectionManagerId()
+  }
+
+  // The reciever's remote address is the local socket on remote side : which is NOT
+  // the connection manager id of the receiver.
+  // We infer that from the messages we receive on the receiver socket.
+  private def processConnectionManagerId(header: MessageChunkHeader) {
+    val currId = inferredRemoteManagerId
+    if (header.address == null || currId != null) return
+
+    val managerId = ConnectionManagerId.fromSocketAddress(header.address)
+
+    if (managerId != null) {
+      inferredRemoteManagerId = managerId
+    }
+  }
+
+
+  val inbox = new Inbox()
+  val headerBuffer: ByteBuffer = ByteBuffer.allocate(MessageChunkHeader.HEADER_SIZE)
+  var onReceiveCallback: (Connection , Message) => Unit = null
+  var currentChunk: MessageChunk = null
+
+  channel.register(selector, SelectionKey.OP_READ)
+
+  override def read(): Boolean = {
+    try {
+      while (true) {
+        if (currentChunk == null) {
+          val headerBytesRead = channel.read(headerBuffer)
+          if (headerBytesRead == -1) {
+            close()
+            return false
+          }
+          if (headerBuffer.remaining > 0) {
+            // re-register for read event ...
+            return true
+          }
+          headerBuffer.flip
+          if (headerBuffer.remaining != MessageChunkHeader.HEADER_SIZE) {
+            throw new Exception(
+              "Unexpected number of bytes (" + headerBuffer.remaining + ") in the header")
+          }
+          val header = MessageChunkHeader.create(headerBuffer)
+          headerBuffer.clear()
+
+          processConnectionManagerId(header)
+
+          header.typ match {
+            case Message.BUFFER_MESSAGE => {
+              if (header.totalSize == 0) {
+                if (onReceiveCallback != null) {
+                  onReceiveCallback(this, Message.create(header))
+                }
+                currentChunk = null
+                // re-register for read event ...
+                return true
+              } else {
+                currentChunk = inbox.getChunk(header).orNull
+              }
+            }
+            case _ => throw new Exception("Message of unknown type received")
+          }
+        }
+
+        if (currentChunk == null) throw new Exception("No message chunk to receive data")
+
+        val bytesRead = channel.read(currentChunk.buffer)
+        if (bytesRead == 0) {
+          // re-register for read event ...
+          return true
+        } else if (bytesRead == -1) {
+          close()
+          return false
+        }
+
+        /*logDebug("Read " + bytesRead + " bytes for the buffer")*/
+
+        if (currentChunk.buffer.remaining == 0) {
+          /*println("Filled buffer at " + System.currentTimeMillis)*/
+          val bufferMessage = inbox.getMessageForChunk(currentChunk).get
+          if (bufferMessage.isCompletelyReceived) {
+            bufferMessage.flip
+            bufferMessage.finishTime = System.currentTimeMillis
+            logDebug("Finished receiving [" + bufferMessage + "] from " +
+              "[" + getRemoteConnectionManagerId() + "] in " + bufferMessage.timeTaken)
+            if (onReceiveCallback != null) {
+              onReceiveCallback(this, bufferMessage)
+            }
+            inbox.removeMessage(bufferMessage)
+          }
+          currentChunk = null
+        }
+      }
+    } catch {
+      case e: Exception  => {
+        logWarning("Error reading from connection to " + getRemoteConnectionManagerId(), e)
+        callOnExceptionCallback(e)
+        close()
+        return false
+      }
+    }
+    // should not happen - to keep scala compiler happy
+    return true
+  }
+
+  def onReceive(callback: (Connection, Message) => Unit) {onReceiveCallback = callback}
+
+  // override def changeInterestForRead(): Boolean = ! isClosed
+  override def changeInterestForRead(): Boolean = true
+
+  override def changeInterestForWrite(): Boolean = {
+    throw new IllegalStateException("Unexpected invocation right now")
+  }
+
+  override def registerInterest() {
+    // Registering read too - does not really help in most cases, but for some
+    // it does - so let us keep it for now.
+    changeConnectionKeyInterest(SelectionKey.OP_READ)
+  }
+
+  override def unregisterInterest() {
+    changeConnectionKeyInterest(0)
+  }
+
+  // For read conn, always false.
+  override def resetForceReregister(): Boolean = false
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
new file mode 100644
index 0000000..9e2233c
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala
@@ -0,0 +1,720 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import org.apache.spark._
+
+import java.nio._
+import java.nio.channels._
+import java.nio.channels.spi._
+import java.net._
+import java.util.concurrent.{LinkedBlockingDeque, TimeUnit, ThreadPoolExecutor}
+
+import scala.collection.mutable.HashSet
+import scala.collection.mutable.HashMap
+import scala.collection.mutable.SynchronizedMap
+import scala.collection.mutable.SynchronizedQueue
+import scala.collection.mutable.ArrayBuffer
+
+import akka.dispatch.{Await, Promise, ExecutionContext, Future}
+import akka.util.Duration
+import akka.util.duration._
+
+
+private[spark] class ConnectionManager(port: Int) extends Logging {
+
+  class MessageStatus(
+      val message: Message,
+      val connectionManagerId: ConnectionManagerId,
+      completionHandler: MessageStatus => Unit) {
+
+    var ackMessage: Option[Message] = None
+    var attempted = false
+    var acked = false
+
+    def markDone() { completionHandler(this) }
+  }
+
+  private val selector = SelectorProvider.provider.openSelector()
+
+  private val handleMessageExecutor = new ThreadPoolExecutor(
+    System.getProperty("spark.core.connection.handler.threads.min","20").toInt,
+    System.getProperty("spark.core.connection.handler.threads.max","60").toInt,
+    System.getProperty("spark.core.connection.handler.threads.keepalive","60").toInt, TimeUnit.SECONDS,
+    new LinkedBlockingDeque[Runnable]())
+
+  private val handleReadWriteExecutor = new ThreadPoolExecutor(
+    System.getProperty("spark.core.connection.io.threads.min","4").toInt,
+    System.getProperty("spark.core.connection.io.threads.max","32").toInt,
+    System.getProperty("spark.core.connection.io.threads.keepalive","60").toInt, TimeUnit.SECONDS,
+    new LinkedBlockingDeque[Runnable]())
+
+  // Use a different, yet smaller, thread pool - infrequently used with very short lived tasks : which should be executed asap
+  private val handleConnectExecutor = new ThreadPoolExecutor(
+    System.getProperty("spark.core.connection.connect.threads.min","1").toInt,
+    System.getProperty("spark.core.connection.connect.threads.max","8").toInt,
+    System.getProperty("spark.core.connection.connect.threads.keepalive","60").toInt, TimeUnit.SECONDS,
+    new LinkedBlockingDeque[Runnable]())
+
+  private val serverChannel = ServerSocketChannel.open()
+  private val connectionsByKey = new HashMap[SelectionKey, Connection] with SynchronizedMap[SelectionKey, Connection]
+  private val connectionsById = new HashMap[ConnectionManagerId, SendingConnection] with SynchronizedMap[ConnectionManagerId, SendingConnection]
+  private val messageStatuses = new HashMap[Int, MessageStatus]
+  private val keyInterestChangeRequests = new SynchronizedQueue[(SelectionKey, Int)]
+  private val registerRequests = new SynchronizedQueue[SendingConnection]
+
+  implicit val futureExecContext = ExecutionContext.fromExecutor(Utils.newDaemonCachedThreadPool())
+
+  private var onReceiveCallback: (BufferMessage, ConnectionManagerId) => Option[Message]= null
+
+  serverChannel.configureBlocking(false)
+  serverChannel.socket.setReuseAddress(true)
+  serverChannel.socket.setReceiveBufferSize(256 * 1024)
+
+  serverChannel.socket.bind(new InetSocketAddress(port))
+  serverChannel.register(selector, SelectionKey.OP_ACCEPT)
+
+  val id = new ConnectionManagerId(Utils.localHostName, serverChannel.socket.getLocalPort)
+  logInfo("Bound socket to port " + serverChannel.socket.getLocalPort() + " with id = " + id)
+
+  private val selectorThread = new Thread("connection-manager-thread") {
+    override def run() = ConnectionManager.this.run()
+  }
+  selectorThread.setDaemon(true)
+  selectorThread.start()
+
+  private val writeRunnableStarted: HashSet[SelectionKey] = new HashSet[SelectionKey]()
+
+  private def triggerWrite(key: SelectionKey) {
+    val conn = connectionsByKey.getOrElse(key, null)
+    if (conn == null) return
+
+    writeRunnableStarted.synchronized {
+      // So that we do not trigger more write events while processing this one.
+      // The write method will re-register when done.
+      if (conn.changeInterestForWrite()) conn.unregisterInterest()
+      if (writeRunnableStarted.contains(key)) {
+        // key.interestOps(key.interestOps() & ~ SelectionKey.OP_WRITE)
+        return
+      }
+
+      writeRunnableStarted += key
+    }
+    handleReadWriteExecutor.execute(new Runnable {
+      override def run() {
+        var register: Boolean = false
+        try {
+          register = conn.write()
+        } finally {
+          writeRunnableStarted.synchronized {
+            writeRunnableStarted -= key
+            val needReregister = register || conn.resetForceReregister()
+            if (needReregister && conn.changeInterestForWrite()) {
+              conn.registerInterest()
+            }
+          }
+        }
+      }
+    } )
+  }
+
+  private val readRunnableStarted: HashSet[SelectionKey] = new HashSet[SelectionKey]()
+
+  private def triggerRead(key: SelectionKey) {
+    val conn = connectionsByKey.getOrElse(key, null)
+    if (conn == null) return
+
+    readRunnableStarted.synchronized {
+      // So that we do not trigger more read events while processing this one.
+      // The read method will re-register when done.
+      if (conn.changeInterestForRead())conn.unregisterInterest()
+      if (readRunnableStarted.contains(key)) {
+        return
+      }
+
+      readRunnableStarted += key
+    }
+    handleReadWriteExecutor.execute(new Runnable {
+      override def run() {
+        var register: Boolean = false
+        try {
+          register = conn.read()
+        } finally {
+          readRunnableStarted.synchronized {
+            readRunnableStarted -= key
+            if (register && conn.changeInterestForRead()) {
+              conn.registerInterest()
+            }
+          }
+        }
+      }
+    } )
+  }
+
+  private def triggerConnect(key: SelectionKey) {
+    val conn = connectionsByKey.getOrElse(key, null).asInstanceOf[SendingConnection]
+    if (conn == null) return
+
+    // prevent other events from being triggered
+    // Since we are still trying to connect, we do not need to do the additional steps in triggerWrite
+    conn.changeConnectionKeyInterest(0)
+
+    handleConnectExecutor.execute(new Runnable {
+      override def run() {
+
+        var tries: Int = 10
+        while (tries >= 0) {
+          if (conn.finishConnect(false)) return
+          // Sleep ?
+          Thread.sleep(1)
+          tries -= 1
+        }
+
+        // fallback to previous behavior : we should not really come here since this method was
+        // triggered since channel became connectable : but at times, the first finishConnect need not
+        // succeed : hence the loop to retry a few 'times'.
+        conn.finishConnect(true)
+      }
+    } )
+  }
+
+  // MUST be called within selector loop - else deadlock.
+  private def triggerForceCloseByException(key: SelectionKey, e: Exception) {
+    try {
+      key.interestOps(0)
+    } catch {
+      // ignore exceptions
+      case e: Exception => logDebug("Ignoring exception", e)
+    }
+
+    val conn = connectionsByKey.getOrElse(key, null)
+    if (conn == null) return
+
+    // Pushing to connect threadpool
+    handleConnectExecutor.execute(new Runnable {
+      override def run() {
+        try {
+          conn.callOnExceptionCallback(e)
+        } catch {
+          // ignore exceptions
+          case e: Exception => logDebug("Ignoring exception", e)
+        }
+        try {
+          conn.close()
+        } catch {
+          // ignore exceptions
+          case e: Exception => logDebug("Ignoring exception", e)
+        }
+      }
+    })
+  }
+
+
+  def run() {
+    try {
+      while(!selectorThread.isInterrupted) {
+        while (! registerRequests.isEmpty) {
+          val conn: SendingConnection = registerRequests.dequeue
+          addListeners(conn)
+          conn.connect()
+          addConnection(conn)
+        }
+
+        while(!keyInterestChangeRequests.isEmpty) {
+          val (key, ops) = keyInterestChangeRequests.dequeue
+
+          try {
+            if (key.isValid) {
+              val connection = connectionsByKey.getOrElse(key, null)
+              if (connection != null) {
+                val lastOps = key.interestOps()
+                key.interestOps(ops)
+
+                // hot loop - prevent materialization of string if trace not enabled.
+                if (isTraceEnabled()) {
+                  def intToOpStr(op: Int): String = {
+                    val opStrs = ArrayBuffer[String]()
+                    if ((op & SelectionKey.OP_READ) != 0) opStrs += "READ"
+                    if ((op & SelectionKey.OP_WRITE) != 0) opStrs += "WRITE"
+                    if ((op & SelectionKey.OP_CONNECT) != 0) opStrs += "CONNECT"
+                    if ((op & SelectionKey.OP_ACCEPT) != 0) opStrs += "ACCEPT"
+                    if (opStrs.size > 0) opStrs.reduceLeft(_ + " | " + _) else " "
+                  }
+
+                  logTrace("Changed key for connection to [" + connection.getRemoteConnectionManagerId()  +
+                    "] changed from [" + intToOpStr(lastOps) + "] to [" + intToOpStr(ops) + "]")
+                }
+              }
+            } else {
+              logInfo("Key not valid ? " + key)
+              throw new CancelledKeyException()
+            }
+          } catch {
+            case e: CancelledKeyException => {
+              logInfo("key already cancelled ? " + key, e)
+              triggerForceCloseByException(key, e)
+            }
+            case e: Exception => {
+              logError("Exception processing key " + key, e)
+              triggerForceCloseByException(key, e)
+            }
+          }
+        }
+
+        val selectedKeysCount =
+          try {
+            selector.select()
+          } catch {
+            // Explicitly only dealing with CancelledKeyException here since other exceptions should be dealt with differently.
+            case e: CancelledKeyException => {
+              // Some keys within the selectors list are invalid/closed. clear them.
+              val allKeys = selector.keys().iterator()
+
+              while (allKeys.hasNext()) {
+                val key = allKeys.next()
+                try {
+                  if (! key.isValid) {
+                    logInfo("Key not valid ? " + key)
+                    throw new CancelledKeyException()
+                  }
+                } catch {
+                  case e: CancelledKeyException => {
+                    logInfo("key already cancelled ? " + key, e)
+                    triggerForceCloseByException(key, e)
+                  }
+                  case e: Exception => {
+                    logError("Exception processing key " + key, e)
+                    triggerForceCloseByException(key, e)
+                  }
+                }
+              }
+            }
+            0
+          }
+
+        if (selectedKeysCount == 0) {
+          logDebug("Selector selected " + selectedKeysCount + " of " + selector.keys.size + " keys")
+        }
+        if (selectorThread.isInterrupted) {
+          logInfo("Selector thread was interrupted!")
+          return
+        }
+
+        if (0 != selectedKeysCount) {
+          val selectedKeys = selector.selectedKeys().iterator()
+          while (selectedKeys.hasNext()) {
+            val key = selectedKeys.next
+            selectedKeys.remove()
+            try {
+              if (key.isValid) {
+                if (key.isAcceptable) {
+                  acceptConnection(key)
+                } else
+                if (key.isConnectable) {
+                  triggerConnect(key)
+                } else
+                if (key.isReadable) {
+                  triggerRead(key)
+                } else
+                if (key.isWritable) {
+                  triggerWrite(key)
+                }
+              } else {
+                logInfo("Key not valid ? " + key)
+                throw new CancelledKeyException()
+              }
+            } catch {
+              // weird, but we saw this happening - even though key.isValid was true, key.isAcceptable would throw CancelledKeyException.
+              case e: CancelledKeyException => {
+                logInfo("key already cancelled ? " + key, e)
+                triggerForceCloseByException(key, e)
+              }
+              case e: Exception => {
+                logError("Exception processing key " + key, e)
+                triggerForceCloseByException(key, e)
+              }
+            }
+          }
+        }
+      }
+    } catch {
+      case e: Exception => logError("Error in select loop", e)
+    }
+  }
+
+  def acceptConnection(key: SelectionKey) {
+    val serverChannel = key.channel.asInstanceOf[ServerSocketChannel]
+
+    var newChannel = serverChannel.accept()
+
+    // accept them all in a tight loop. non blocking accept with no processing, should be fine
+    while (newChannel != null) {
+      try {
+        val newConnection = new ReceivingConnection(newChannel, selector)
+        newConnection.onReceive(receiveMessage)
+        addListeners(newConnection)
+        addConnection(newConnection)
+        logInfo("Accepted connection from [" + newConnection.remoteAddress.getAddress + "]")
+      } catch {
+        // might happen in case of issues with registering with selector
+        case e: Exception => logError("Error in accept loop", e)
+      }
+
+      newChannel = serverChannel.accept()
+    }
+  }
+
+  private def addListeners(connection: Connection) {
+    connection.onKeyInterestChange(changeConnectionKeyInterest)
+    connection.onException(handleConnectionError)
+    connection.onClose(removeConnection)
+  }
+
+  def addConnection(connection: Connection) {
+    connectionsByKey += ((connection.key, connection))
+  }
+
+  def removeConnection(connection: Connection) {
+    connectionsByKey -= connection.key
+
+    try {
+      if (connection.isInstanceOf[SendingConnection]) {
+        val sendingConnection = connection.asInstanceOf[SendingConnection]
+        val sendingConnectionManagerId = sendingConnection.getRemoteConnectionManagerId()
+        logInfo("Removing SendingConnection to " + sendingConnectionManagerId)
+
+        connectionsById -= sendingConnectionManagerId
+
+        messageStatuses.synchronized {
+          messageStatuses
+            .values.filter(_.connectionManagerId == sendingConnectionManagerId).foreach(status => {
+              logInfo("Notifying " + status)
+              status.synchronized {
+              status.attempted = true
+               status.acked = false
+               status.markDone()
+              }
+            })
+
+          messageStatuses.retain((i, status) => {
+            status.connectionManagerId != sendingConnectionManagerId
+          })
+        }
+      } else if (connection.isInstanceOf[ReceivingConnection]) {
+        val receivingConnection = connection.asInstanceOf[ReceivingConnection]
+        val remoteConnectionManagerId = receivingConnection.getRemoteConnectionManagerId()
+        logInfo("Removing ReceivingConnection to " + remoteConnectionManagerId)
+
+        val sendingConnectionOpt = connectionsById.get(remoteConnectionManagerId)
+          if (! sendingConnectionOpt.isDefined) {
+          logError("Corresponding SendingConnectionManagerId not found")
+          return
+        }
+
+        val sendingConnection = sendingConnectionOpt.get
+        connectionsById -= remoteConnectionManagerId
+        sendingConnection.close()
+
+        val sendingConnectionManagerId = sendingConnection.getRemoteConnectionManagerId()
+
+        assert (sendingConnectionManagerId == remoteConnectionManagerId)
+
+        messageStatuses.synchronized {
+          for (s <- messageStatuses.values if s.connectionManagerId == sendingConnectionManagerId) {
+            logInfo("Notifying " + s)
+            s.synchronized {
+              s.attempted = true
+              s.acked = false
+              s.markDone()
+            }
+          }
+
+          messageStatuses.retain((i, status) => {
+            status.connectionManagerId != sendingConnectionManagerId
+          })
+        }
+      }
+    } finally {
+      // So that the selection keys can be removed.
+      wakeupSelector()
+    }
+  }
+
+  def handleConnectionError(connection: Connection, e: Exception) {
+    logInfo("Handling connection error on connection to " + connection.getRemoteConnectionManagerId())
+    removeConnection(connection)
+  }
+
+  def changeConnectionKeyInterest(connection: Connection, ops: Int) {
+    keyInterestChangeRequests += ((connection.key, ops))
+    // so that registerations happen !
+    wakeupSelector()
+  }
+
+  def receiveMessage(connection: Connection, message: Message) {
+    val connectionManagerId = ConnectionManagerId.fromSocketAddress(message.senderAddress)
+    logDebug("Received [" + message + "] from [" + connectionManagerId + "]")
+    val runnable = new Runnable() {
+      val creationTime = System.currentTimeMillis
+      def run() {
+        logDebug("Handler thread delay is " + (System.currentTimeMillis - creationTime) + " ms")
+        handleMessage(connectionManagerId, message)
+        logDebug("Handling delay is " + (System.currentTimeMillis - creationTime) + " ms")
+      }
+    }
+    handleMessageExecutor.execute(runnable)
+    /*handleMessage(connection, message)*/
+  }
+
+  private def handleMessage(connectionManagerId: ConnectionManagerId, message: Message) {
+    logDebug("Handling [" + message + "] from [" + connectionManagerId + "]")
+    message match {
+      case bufferMessage: BufferMessage => {
+        if (bufferMessage.hasAckId) {
+          val sentMessageStatus = messageStatuses.synchronized {
+            messageStatuses.get(bufferMessage.ackId) match {
+              case Some(status) => {
+                messageStatuses -= bufferMessage.ackId
+                status
+              }
+              case None => {
+                throw new Exception("Could not find reference for received ack message " + message.id)
+                null
+              }
+            }
+          }
+          sentMessageStatus.synchronized {
+            sentMessageStatus.ackMessage = Some(message)
+            sentMessageStatus.attempted = true
+            sentMessageStatus.acked = true
+            sentMessageStatus.markDone()
+          }
+        } else {
+          val ackMessage = if (onReceiveCallback != null) {
+            logDebug("Calling back")
+            onReceiveCallback(bufferMessage, connectionManagerId)
+          } else {
+            logDebug("Not calling back as callback is null")
+            None
+          }
+
+          if (ackMessage.isDefined) {
+            if (!ackMessage.get.isInstanceOf[BufferMessage]) {
+              logDebug("Response to " + bufferMessage + " is not a buffer message, it is of type " + ackMessage.get.getClass())
+            } else if (!ackMessage.get.asInstanceOf[BufferMessage].hasAckId) {
+              logDebug("Response to " + bufferMessage + " does not have ack id set")
+              ackMessage.get.asInstanceOf[BufferMessage].ackId = bufferMessage.id
+            }
+          }
+
+          sendMessage(connectionManagerId, ackMessage.getOrElse {
+            Message.createBufferMessage(bufferMessage.id)
+          })
+        }
+      }
+      case _ => throw new Exception("Unknown type message received")
+    }
+  }
+
+  private def sendMessage(connectionManagerId: ConnectionManagerId, message: Message) {
+    def startNewConnection(): SendingConnection = {
+      val inetSocketAddress = new InetSocketAddress(connectionManagerId.host, connectionManagerId.port)
+      val newConnection = new SendingConnection(inetSocketAddress, selector, connectionManagerId)
+      registerRequests.enqueue(newConnection)
+
+      newConnection
+    }
+    // I removed the lookupKey stuff as part of merge ... should I re-add it ? We did not find it useful in our test-env ...
+    // If we do re-add it, we should consistently use it everywhere I guess ?
+    val connection = connectionsById.getOrElseUpdate(connectionManagerId, startNewConnection())
+    message.senderAddress = id.toSocketAddress()
+    logDebug("Sending [" + message + "] to [" + connectionManagerId + "]")
+    connection.send(message)
+
+    wakeupSelector()
+  }
+
+  private def wakeupSelector() {
+    selector.wakeup()
+  }
+
+  def sendMessageReliably(connectionManagerId: ConnectionManagerId, message: Message)
+      : Future[Option[Message]] = {
+    val promise = Promise[Option[Message]]
+    val status = new MessageStatus(message, connectionManagerId, s => promise.success(s.ackMessage))
+    messageStatuses.synchronized {
+      messageStatuses += ((message.id, status))
+    }
+    sendMessage(connectionManagerId, message)
+    promise.future
+  }
+
+  def sendMessageReliablySync(connectionManagerId: ConnectionManagerId, message: Message): Option[Message] = {
+    Await.result(sendMessageReliably(connectionManagerId, message), Duration.Inf)
+  }
+
+  def onReceiveMessage(callback: (Message, ConnectionManagerId) => Option[Message]) {
+    onReceiveCallback = callback
+  }
+
+  def stop() {
+    selectorThread.interrupt()
+    selectorThread.join()
+    selector.close()
+    val connections = connectionsByKey.values
+    connections.foreach(_.close())
+    if (connectionsByKey.size != 0) {
+      logWarning("All connections not cleaned up")
+    }
+    handleMessageExecutor.shutdown()
+    handleReadWriteExecutor.shutdown()
+    handleConnectExecutor.shutdown()
+    logInfo("ConnectionManager stopped")
+  }
+}
+
+
+private[spark] object ConnectionManager {
+
+  def main(args: Array[String]) {
+    val manager = new ConnectionManager(9999)
+    manager.onReceiveMessage((msg: Message, id: ConnectionManagerId) => {
+      println("Received [" + msg + "] from [" + id + "]")
+      None
+    })
+
+    /*testSequentialSending(manager)*/
+    /*System.gc()*/
+
+    /*testParallelSending(manager)*/
+    /*System.gc()*/
+
+    /*testParallelDecreasingSending(manager)*/
+    /*System.gc()*/
+
+    testContinuousSending(manager)
+    System.gc()
+  }
+
+  def testSequentialSending(manager: ConnectionManager) {
+    println("--------------------------")
+    println("Sequential Sending")
+    println("--------------------------")
+    val size = 10 * 1024 * 1024
+    val count = 10
+
+    val buffer = ByteBuffer.allocate(size).put(Array.tabulate[Byte](size)(x => x.toByte))
+    buffer.flip
+
+    (0 until count).map(i => {
+      val bufferMessage = Message.createBufferMessage(buffer.duplicate)
+      manager.sendMessageReliablySync(manager.id, bufferMessage)
+    })
+    println("--------------------------")
+    println()
+  }
+
+  def testParallelSending(manager: ConnectionManager) {
+    println("--------------------------")
+    println("Parallel Sending")
+    println("--------------------------")
+    val size = 10 * 1024 * 1024
+    val count = 10
+
+    val buffer = ByteBuffer.allocate(size).put(Array.tabulate[Byte](size)(x => x.toByte))
+    buffer.flip
+
+    val startTime = System.currentTimeMillis
+    (0 until count).map(i => {
+      val bufferMessage = Message.createBufferMessage(buffer.duplicate)
+      manager.sendMessageReliably(manager.id, bufferMessage)
+    }).foreach(f => {
+      val g = Await.result(f, 1 second)
+      if (!g.isDefined) println("Failed")
+    })
+    val finishTime = System.currentTimeMillis
+
+    val mb = size * count / 1024.0 / 1024.0
+    val ms = finishTime - startTime
+    val tput = mb * 1000.0 / ms
+    println("--------------------------")
+    println("Started at " + startTime + ", finished at " + finishTime)
+    println("Sent " + count + " messages of size " + size + " in " + ms + " ms (" + tput + " MB/s)")
+    println("--------------------------")
+    println()
+  }
+
+  def testParallelDecreasingSending(manager: ConnectionManager) {
+    println("--------------------------")
+    println("Parallel Decreasing Sending")
+    println("--------------------------")
+    val size = 10 * 1024 * 1024
+    val count = 10
+    val buffers = Array.tabulate(count)(i => ByteBuffer.allocate(size * (i + 1)).put(Array.tabulate[Byte](size * (i + 1))(x => x.toByte)))
+    buffers.foreach(_.flip)
+    val mb = buffers.map(_.remaining).reduceLeft(_ + _) / 1024.0 / 1024.0
+
+    val startTime = System.currentTimeMillis
+    (0 until count).map(i => {
+      val bufferMessage = Message.createBufferMessage(buffers(count - 1 - i).duplicate)
+      manager.sendMessageReliably(manager.id, bufferMessage)
+    }).foreach(f => {
+      val g = Await.result(f, 1 second)
+      if (!g.isDefined) println("Failed")
+    })
+    val finishTime = System.currentTimeMillis
+
+    val ms = finishTime - startTime
+    val tput = mb * 1000.0 / ms
+    println("--------------------------")
+    /*println("Started at " + startTime + ", finished at " + finishTime) */
+    println("Sent " + mb + " MB in " + ms + " ms (" + tput + " MB/s)")
+    println("--------------------------")
+    println()
+  }
+
+  def testContinuousSending(manager: ConnectionManager) {
+    println("--------------------------")
+    println("Continuous Sending")
+    println("--------------------------")
+    val size = 10 * 1024 * 1024
+    val count = 10
+
+    val buffer = ByteBuffer.allocate(size).put(Array.tabulate[Byte](size)(x => x.toByte))
+    buffer.flip
+
+    val startTime = System.currentTimeMillis
+    while(true) {
+      (0 until count).map(i => {
+          val bufferMessage = Message.createBufferMessage(buffer.duplicate)
+          manager.sendMessageReliably(manager.id, bufferMessage)
+        }).foreach(f => {
+          val g = Await.result(f, 1 second)
+          if (!g.isDefined) println("Failed")
+        })
+      val finishTime = System.currentTimeMillis
+      Thread.sleep(1000)
+      val mb = size * count / 1024.0 / 1024.0
+      val ms = finishTime - startTime
+      val tput = mb * 1000.0 / ms
+      println("Sent " + mb + " MB in " + ms + " ms (" + tput + " MB/s)")
+      println("--------------------------")
+      println()
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
new file mode 100644
index 0000000..0839c01
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/ConnectionManagerId.scala
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.net.InetSocketAddress
+
+import org.apache.spark.Utils
+
+
+private[spark] case class ConnectionManagerId(host: String, port: Int) {
+  // DEBUG code
+  Utils.checkHost(host)
+  assert (port > 0)
+
+  def toSocketAddress() = new InetSocketAddress(host, port)
+}
+
+
+private[spark] object ConnectionManagerId {
+  def fromSocketAddress(socketAddress: InetSocketAddress): ConnectionManagerId = {
+    new ConnectionManagerId(socketAddress.getHostName(), socketAddress.getPort())
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/ConnectionManagerTest.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManagerTest.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManagerTest.scala
new file mode 100644
index 0000000..8d9ad96
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/ConnectionManagerTest.scala
@@ -0,0 +1,102 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import org.apache.spark._
+import org.apache.spark.SparkContext._
+
+import scala.io.Source
+
+import java.nio.ByteBuffer
+import java.net.InetAddress
+
+import akka.dispatch.Await
+import akka.util.duration._
+
+private[spark] object ConnectionManagerTest extends Logging{
+  def main(args: Array[String]) {
+    //<mesos cluster> - the master URL
+    //<slaves file> - a list slaves to run connectionTest on
+    //[num of tasks] - the number of parallel tasks to be initiated default is number of slave hosts
+    //[size of msg in MB (integer)] - the size of messages to be sent in each task, default is 10
+    //[count] - how many times to run, default is 3
+    //[await time in seconds] : await time (in seconds), default is 600
+    if (args.length < 2) {
+      println("Usage: ConnectionManagerTest <mesos cluster> <slaves file> [num of tasks] [size of msg in MB (integer)] [count] [await time in seconds)] ")
+      System.exit(1)
+    }
+    
+    if (args(0).startsWith("local")) {
+      println("This runs only on a mesos cluster")
+    }
+    
+    val sc = new SparkContext(args(0), "ConnectionManagerTest")
+    val slavesFile = Source.fromFile(args(1))
+    val slaves = slavesFile.mkString.split("\n")
+    slavesFile.close()
+
+    /*println("Slaves")*/
+    /*slaves.foreach(println)*/
+    val tasknum = if (args.length > 2) args(2).toInt else slaves.length
+    val size = ( if (args.length > 3) (args(3).toInt) else 10 ) * 1024 * 1024 
+    val count = if (args.length > 4) args(4).toInt else 3
+    val awaitTime = (if (args.length > 5) args(5).toInt else 600 ).second
+    println("Running "+count+" rounds of test: " + "parallel tasks = " + tasknum + ", msg size = " + size/1024/1024 + " MB, awaitTime = " + awaitTime)
+    val slaveConnManagerIds = sc.parallelize(0 until tasknum, tasknum).map(
+        i => SparkEnv.get.connectionManager.id).collect()
+    println("\nSlave ConnectionManagerIds")
+    slaveConnManagerIds.foreach(println)
+    println
+
+    (0 until count).foreach(i => {
+      val resultStrs = sc.parallelize(0 until tasknum, tasknum).map(i => {
+        val connManager = SparkEnv.get.connectionManager
+        val thisConnManagerId = connManager.id 
+        connManager.onReceiveMessage((msg: Message, id: ConnectionManagerId) => { 
+          logInfo("Received [" + msg + "] from [" + id + "]")
+          None
+        })
+
+        val buffer = ByteBuffer.allocate(size).put(Array.tabulate[Byte](size)(x => x.toByte))
+        buffer.flip
+        
+        val startTime = System.currentTimeMillis  
+        val futures = slaveConnManagerIds.filter(_ != thisConnManagerId).map(slaveConnManagerId => {
+          val bufferMessage = Message.createBufferMessage(buffer.duplicate)
+          logInfo("Sending [" + bufferMessage + "] to [" + slaveConnManagerId + "]")
+          connManager.sendMessageReliably(slaveConnManagerId, bufferMessage)
+        })
+        val results = futures.map(f => Await.result(f, awaitTime))
+        val finishTime = System.currentTimeMillis
+        Thread.sleep(5000)
+        
+        val mb = size * results.size / 1024.0 / 1024.0
+        val ms = finishTime - startTime
+        val resultStr = thisConnManagerId + " Sent " + mb + " MB in " + ms + " ms at " + (mb / ms * 1000.0) + " MB/s"
+        logInfo(resultStr)
+        resultStr
+      }).collect()
+      
+      println("---------------------") 
+      println("Run " + i) 
+      resultStrs.foreach(println)
+      println("---------------------") 
+    })
+  }
+}
+

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/Message.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/Message.scala b/core/src/main/scala/org/apache/spark/network/Message.scala
new file mode 100644
index 0000000..f2ecc6d
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/Message.scala
@@ -0,0 +1,93 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.nio.ByteBuffer
+import java.net.InetSocketAddress
+
+import scala.collection.mutable.ArrayBuffer
+
+
+private[spark] abstract class Message(val typ: Long, val id: Int) {
+  var senderAddress: InetSocketAddress = null
+  var started = false
+  var startTime = -1L
+  var finishTime = -1L
+
+  def size: Int
+
+  def getChunkForSending(maxChunkSize: Int): Option[MessageChunk]
+
+  def getChunkForReceiving(chunkSize: Int): Option[MessageChunk]
+
+  def timeTaken(): String = (finishTime - startTime).toString + " ms"
+
+  override def toString = this.getClass.getSimpleName + "(id = " + id + ", size = " + size + ")"
+}
+
+
+private[spark] object Message {
+  val BUFFER_MESSAGE = 1111111111L
+
+  var lastId = 1
+
+  def getNewId() = synchronized {
+    lastId += 1
+    if (lastId == 0) {
+      lastId += 1
+    }
+    lastId
+  }
+
+  def createBufferMessage(dataBuffers: Seq[ByteBuffer], ackId: Int): BufferMessage = {
+    if (dataBuffers == null) {
+      return new BufferMessage(getNewId(), new ArrayBuffer[ByteBuffer], ackId)
+    }
+    if (dataBuffers.exists(_ == null)) {
+      throw new Exception("Attempting to create buffer message with null buffer")
+    }
+    return new BufferMessage(getNewId(), new ArrayBuffer[ByteBuffer] ++= dataBuffers, ackId)
+  }
+
+  def createBufferMessage(dataBuffers: Seq[ByteBuffer]): BufferMessage =
+    createBufferMessage(dataBuffers, 0)
+
+  def createBufferMessage(dataBuffer: ByteBuffer, ackId: Int): BufferMessage = {
+    if (dataBuffer == null) {
+      return createBufferMessage(Array(ByteBuffer.allocate(0)), ackId)
+    } else {
+      return createBufferMessage(Array(dataBuffer), ackId)
+    }
+  }
+
+  def createBufferMessage(dataBuffer: ByteBuffer): BufferMessage =
+    createBufferMessage(dataBuffer, 0)
+
+  def createBufferMessage(ackId: Int): BufferMessage = {
+    createBufferMessage(new Array[ByteBuffer](0), ackId)
+  }
+
+  def create(header: MessageChunkHeader): Message = {
+    val newMessage: Message = header.typ match {
+      case BUFFER_MESSAGE => new BufferMessage(header.id,
+        ArrayBuffer(ByteBuffer.allocate(header.totalSize)), header.other)
+    }
+    newMessage.senderAddress = header.address
+    newMessage
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/MessageChunk.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/MessageChunk.scala b/core/src/main/scala/org/apache/spark/network/MessageChunk.scala
new file mode 100644
index 0000000..e0fe57b
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/MessageChunk.scala
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.nio.ByteBuffer
+
+import scala.collection.mutable.ArrayBuffer
+
+
+private[network]
+class MessageChunk(val header: MessageChunkHeader, val buffer: ByteBuffer) {
+
+  val size = if (buffer == null) 0 else buffer.remaining
+
+  lazy val buffers = {
+    val ab = new ArrayBuffer[ByteBuffer]()
+    ab += header.buffer
+    if (buffer != null) {
+      ab += buffer
+    }
+    ab
+  }
+
+  override def toString = {
+    "" + this.getClass.getSimpleName + " (id = " + header.id + ", size = " + size + ")"
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/MessageChunkHeader.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/MessageChunkHeader.scala b/core/src/main/scala/org/apache/spark/network/MessageChunkHeader.scala
new file mode 100644
index 0000000..235fbc3
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/MessageChunkHeader.scala
@@ -0,0 +1,75 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+
+
+private[spark] class MessageChunkHeader(
+    val typ: Long,
+    val id: Int,
+    val totalSize: Int,
+    val chunkSize: Int,
+    val other: Int,
+    val address: InetSocketAddress) {
+  lazy val buffer = {
+    // No need to change this, at 'use' time, we do a reverse lookup of the hostname.
+    // Refer to network.Connection
+    val ip = address.getAddress.getAddress()
+    val port = address.getPort()
+    ByteBuffer.
+      allocate(MessageChunkHeader.HEADER_SIZE).
+      putLong(typ).
+      putInt(id).
+      putInt(totalSize).
+      putInt(chunkSize).
+      putInt(other).
+      putInt(ip.size).
+      put(ip).
+      putInt(port).
+      position(MessageChunkHeader.HEADER_SIZE).
+      flip.asInstanceOf[ByteBuffer]
+  }
+
+  override def toString = "" + this.getClass.getSimpleName + ":" + id + " of type " + typ +
+      " and sizes " + totalSize + " / " + chunkSize + " bytes"
+}
+
+
+private[spark] object MessageChunkHeader {
+  val HEADER_SIZE = 40
+
+  def create(buffer: ByteBuffer): MessageChunkHeader = {
+    if (buffer.remaining != HEADER_SIZE) {
+      throw new IllegalArgumentException("Cannot convert buffer data to Message")
+    }
+    val typ = buffer.getLong()
+    val id = buffer.getInt()
+    val totalSize = buffer.getInt()
+    val chunkSize = buffer.getInt()
+    val other = buffer.getInt()
+    val ipSize = buffer.getInt()
+    val ipBytes = new Array[Byte](ipSize)
+    buffer.get(ipBytes)
+    val ip = InetAddress.getByAddress(ipBytes)
+    val port = buffer.getInt()
+    new MessageChunkHeader(typ, id, totalSize, chunkSize, other, new InetSocketAddress(ip, port))
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/ReceiverTest.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/ReceiverTest.scala b/core/src/main/scala/org/apache/spark/network/ReceiverTest.scala
new file mode 100644
index 0000000..7817151
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/ReceiverTest.scala
@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.nio.ByteBuffer
+import java.net.InetAddress
+
+private[spark] object ReceiverTest {
+
+  def main(args: Array[String]) {
+    val manager = new ConnectionManager(9999)
+    println("Started connection manager with id = " + manager.id)
+    
+    manager.onReceiveMessage((msg: Message, id: ConnectionManagerId) => { 
+      /*println("Received [" + msg + "] from [" + id + "] at " + System.currentTimeMillis)*/
+      val buffer = ByteBuffer.wrap("response".getBytes())
+      Some(Message.createBufferMessage(buffer, msg.id))
+    })
+    Thread.currentThread.join()  
+  }
+}
+

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/SenderTest.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/SenderTest.scala b/core/src/main/scala/org/apache/spark/network/SenderTest.scala
new file mode 100644
index 0000000..7775749
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/SenderTest.scala
@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network
+
+import java.nio.ByteBuffer
+import java.net.InetAddress
+
+private[spark] object SenderTest {
+
+  def main(args: Array[String]) {
+    
+    if (args.length < 2) {
+      println("Usage: SenderTest <target host> <target port>")
+      System.exit(1)
+    }
+   
+    val targetHost = args(0)
+    val targetPort = args(1).toInt
+    val targetConnectionManagerId = new ConnectionManagerId(targetHost, targetPort)
+
+    val manager = new ConnectionManager(0)
+    println("Started connection manager with id = " + manager.id)
+
+    manager.onReceiveMessage((msg: Message, id: ConnectionManagerId) => { 
+      println("Received [" + msg + "] from [" + id + "]")
+      None
+    })
+  
+    val size =  100 * 1024  * 1024 
+    val buffer = ByteBuffer.allocate(size).put(Array.tabulate[Byte](size)(x => x.toByte))
+    buffer.flip
+
+    val targetServer = args(0)
+
+    val count = 100
+    (0 until count).foreach(i => {
+      val dataMessage = Message.createBufferMessage(buffer.duplicate)
+      val startTime = System.currentTimeMillis  
+      /*println("Started timer at " + startTime)*/
+      val responseStr = manager.sendMessageReliablySync(targetConnectionManagerId, dataMessage) match {
+        case Some(response) =>
+          val buffer = response.asInstanceOf[BufferMessage].buffers(0)
+          new String(buffer.array)
+        case None => "none"
+      }
+      val finishTime = System.currentTimeMillis
+      val mb = size / 1024.0 / 1024.0
+      val ms = finishTime - startTime
+      /*val resultStr = "Sent " + mb + " MB " + targetServer + " in " + ms + " ms at " + (mb / ms * 1000.0) + " MB/s"*/
+      val resultStr = "Sent " + mb + " MB " + targetServer + " in " + ms + " ms (" +  (mb / ms * 1000.0).toInt + "MB/s) | Response = " + responseStr
+      println(resultStr)
+    })
+  }
+}
+

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/netty/FileHeader.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/netty/FileHeader.scala b/core/src/main/scala/org/apache/spark/network/netty/FileHeader.scala
new file mode 100644
index 0000000..3c29700
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/netty/FileHeader.scala
@@ -0,0 +1,74 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network.netty
+
+import io.netty.buffer._
+
+import org.apache.spark.Logging
+
+private[spark] class FileHeader (
+  val fileLen: Int,
+  val blockId: String) extends Logging {
+
+  lazy val buffer = {
+    val buf = Unpooled.buffer()
+    buf.capacity(FileHeader.HEADER_SIZE)
+    buf.writeInt(fileLen)
+    buf.writeInt(blockId.length)
+    blockId.foreach((x: Char) => buf.writeByte(x))
+    //padding the rest of header
+    if (FileHeader.HEADER_SIZE - buf.readableBytes > 0 ) {
+      buf.writeZero(FileHeader.HEADER_SIZE - buf.readableBytes)
+    } else {
+      throw new Exception("too long header " + buf.readableBytes) 
+      logInfo("too long header") 
+    }
+    buf
+  }
+
+}
+
+private[spark] object FileHeader {
+
+  val HEADER_SIZE = 40
+
+  def getFileLenOffset = 0
+  def getFileLenSize = Integer.SIZE/8
+
+  def create(buf: ByteBuf): FileHeader = {
+    val length = buf.readInt
+    val idLength = buf.readInt
+    val idBuilder = new StringBuilder(idLength)
+    for (i <- 1 to idLength) {
+      idBuilder += buf.readByte().asInstanceOf[Char]
+    }
+    val blockId = idBuilder.toString()
+    new FileHeader(length, blockId)
+  }
+
+
+  def main (args:Array[String]){
+
+    val header = new FileHeader(25,"block_0");
+    val buf = header.buffer;
+    val newheader = FileHeader.create(buf);
+    System.out.println("id="+newheader.blockId+",size="+newheader.fileLen)
+
+  }
+}
+

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/netty/ShuffleCopier.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/netty/ShuffleCopier.scala b/core/src/main/scala/org/apache/spark/network/netty/ShuffleCopier.scala
new file mode 100644
index 0000000..9493ccf
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/netty/ShuffleCopier.scala
@@ -0,0 +1,118 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network.netty
+
+import java.util.concurrent.Executors
+
+import io.netty.buffer.ByteBuf
+import io.netty.channel.ChannelHandlerContext
+import io.netty.util.CharsetUtil
+
+import org.apache.spark.Logging
+import org.apache.spark.network.ConnectionManagerId
+
+import scala.collection.JavaConverters._
+
+
+private[spark] class ShuffleCopier extends Logging {
+
+  def getBlock(host: String, port: Int, blockId: String,
+      resultCollectCallback: (String, Long, ByteBuf) => Unit) {
+
+    val handler = new ShuffleCopier.ShuffleClientHandler(resultCollectCallback)
+    val connectTimeout = System.getProperty("spark.shuffle.netty.connect.timeout", "60000").toInt
+    val fc = new FileClient(handler, connectTimeout)
+
+    try {
+      fc.init()
+      fc.connect(host, port)
+      fc.sendRequest(blockId)
+      fc.waitForClose()
+      fc.close()
+    } catch {
+      // Handle any socket-related exceptions in FileClient
+      case e: Exception => {
+        logError("Shuffle copy of block " + blockId + " from " + host + ":" + port + " failed", e)
+        handler.handleError(blockId)
+      }
+    }
+  }
+
+  def getBlock(cmId: ConnectionManagerId, blockId: String,
+      resultCollectCallback: (String, Long, ByteBuf) => Unit) {
+    getBlock(cmId.host, cmId.port, blockId, resultCollectCallback)
+  }
+
+  def getBlocks(cmId: ConnectionManagerId,
+    blocks: Seq[(String, Long)],
+    resultCollectCallback: (String, Long, ByteBuf) => Unit) {
+
+    for ((blockId, size) <- blocks) {
+      getBlock(cmId, blockId, resultCollectCallback)
+    }
+  }
+}
+
+
+private[spark] object ShuffleCopier extends Logging {
+
+  private class ShuffleClientHandler(resultCollectCallBack: (String, Long, ByteBuf) => Unit)
+    extends FileClientHandler with Logging {
+
+    override def handle(ctx: ChannelHandlerContext, in: ByteBuf, header: FileHeader) {
+      logDebug("Received Block: " + header.blockId + " (" + header.fileLen + "B)");
+      resultCollectCallBack(header.blockId, header.fileLen.toLong, in.readBytes(header.fileLen))
+    }
+
+    override def handleError(blockId: String) {
+      if (!isComplete) {
+        resultCollectCallBack(blockId, -1, null)
+      }
+    }
+  }
+
+  def echoResultCollectCallBack(blockId: String, size: Long, content: ByteBuf) {
+    if (size != -1) {
+      logInfo("File: " + blockId + " content is : \" " + content.toString(CharsetUtil.UTF_8) + "\"")
+    }
+  }
+
+  def main(args: Array[String]) {
+    if (args.length < 3) {
+      System.err.println("Usage: ShuffleCopier <host> <port> <shuffle_block_id> <threads>")
+      System.exit(1)
+    }
+    val host = args(0)
+    val port = args(1).toInt
+    val file = args(2)
+    val threads = if (args.length > 3) args(3).toInt else 10
+
+    val copiers = Executors.newFixedThreadPool(80)
+    val tasks = (for (i <- Range(0, threads)) yield { 
+      Executors.callable(new Runnable() {
+        def run() {
+          val copier = new ShuffleCopier()
+          copier.getBlock(host, port, file, echoResultCollectCallBack)
+        }
+      })
+    }).asJava
+    copiers.invokeAll(tasks)
+    copiers.shutdown
+    System.exit(0)
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/network/netty/ShuffleSender.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/network/netty/ShuffleSender.scala b/core/src/main/scala/org/apache/spark/network/netty/ShuffleSender.scala
new file mode 100644
index 0000000..537f225
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/network/netty/ShuffleSender.scala
@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.network.netty
+
+import java.io.File
+
+import org.apache.spark.Logging
+
+
+private[spark] class ShuffleSender(portIn: Int, val pResolver: PathResolver) extends Logging {
+
+  val server = new FileServer(pResolver, portIn)
+  server.start()
+
+  def stop() {
+    server.stop()
+  }
+
+  def port: Int = server.getPort()
+}
+
+
+/**
+ * An application for testing the shuffle sender as a standalone program.
+ */
+private[spark] object ShuffleSender {
+
+  def main(args: Array[String]) {
+    if (args.length < 3) {
+      System.err.println(
+        "Usage: ShuffleSender <port> <subDirsPerLocalDir> <list of shuffle_block_directories>")
+      System.exit(1)
+    }
+
+    val port = args(0).toInt
+    val subDirsPerLocalDir = args(1).toInt
+    val localDirs = args.drop(2).map(new File(_))
+
+    val pResovler = new PathResolver {
+      override def getAbsolutePath(blockId: String): String = {
+        if (!blockId.startsWith("shuffle_")) {
+          throw new Exception("Block " + blockId + " is not a shuffle block")
+        }
+        // Figure out which local directory it hashes to, and which subdirectory in that
+        val hash = math.abs(blockId.hashCode)
+        val dirId = hash % localDirs.length
+        val subDirId = (hash / localDirs.length) % subDirsPerLocalDir
+        val subDir = new File(localDirs(dirId), "%02x".format(subDirId))
+        val file = new File(subDir, blockId)
+        return file.getAbsolutePath
+      }
+    }
+    val sender = new ShuffleSender(port, pResovler)
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-spark/blob/46eecd11/core/src/main/scala/org/apache/spark/package.scala
----------------------------------------------------------------------
diff --git a/core/src/main/scala/org/apache/spark/package.scala b/core/src/main/scala/org/apache/spark/package.scala
new file mode 100644
index 0000000..1126480
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/package.scala
@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Core Spark functionality. [[org.apache.spark.SparkContext]] serves as the main entry point to Spark, while
+ * [[org.apache.spark.RDD]] is the data type representing a distributed collection, and provides most
+ * parallel operations. 
+ *
+ * In addition, [[org.apache.spark.PairRDDFunctions]] contains operations available only on RDDs of key-value
+ * pairs, such as `groupByKey` and `join`; [[org.apache.spark.DoubleRDDFunctions]] contains operations
+ * available only on RDDs of Doubles; and [[org.apache.spark.SequenceFileRDDFunctions]] contains operations
+ * available on RDDs that can be saved as SequenceFiles. These operations are automatically
+ * available on any RDD of the right type (e.g. RDD[(Int, Int)] through implicit conversions when
+ * you `import org.apache.spark.SparkContext._`.
+ */
+package object spark { 
+  // For package docs only
+}