[SPARK-13843][STREAMING] Remove streaming-flume, streaming-mqtt, streaming-zeromq, streaming-akka, streaming-twitter to Spark packages

## What changes were proposed in this pull request?

Currently there are a few sub-projects, each for integrating with different external sources for Streaming.  Now that we have better ability to include external libraries (spark packages) and with Spark 2.0 coming up, we can move the following projects out of Spark to https://github.com/spark-packages

- streaming-flume
- streaming-akka
- streaming-mqtt
- streaming-zeromq
- streaming-twitter

They are just some ancillary packages and considering the overhead of maintenance, running tests and PR failures, it's better to maintain them out of Spark. In addition, these projects can have their different release cycles and we can release them faster.

I have already copied these projects to https://github.com/spark-packages

## How was this patch tested?

Jenkins tests

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #11672 from zsxwing/remove-external-pkg.

10 files changed, 0 insertions, 1194 deletions

diff --git a/external/flume-sink/pom.xml b/external/flume-sink/pom.xml
deleted file mode 100644
index e4effe158c..0000000000
--- a/external/flume-sink/pom.xml
+++ /dev/null
@@ -1,129 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!--
-  ~ 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.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>org.apache.spark</groupId>
-    <artifactId>spark-parent_2.11</artifactId>
-    <version>2.0.0-SNAPSHOT</version>
-    <relativePath>../../pom.xml</relativePath>
-  </parent>
-
-  <groupId>org.apache.spark</groupId>
-  <artifactId>spark-streaming-flume-sink_2.11</artifactId>
-  <properties>
-    <sbt.project.name>streaming-flume-sink</sbt.project.name>
-  </properties>
-  <packaging>jar</packaging>
-  <name>Spark Project External Flume Sink</name>
-  <url>http://spark.apache.org/</url>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.apache.flume</groupId>
-      <artifactId>flume-ng-sdk</artifactId>
-      <exclusions>
-        <!-- Guava is excluded to avoid its use in this module. -->
-        <exclusion>
-          <groupId>com.google.guava</groupId>
-          <artifactId>guava</artifactId>
-        </exclusion>
-        <!--
-          Exclude libthrift since the flume poms seem to confuse sbt, which fails to find the
-          dependency.
-        -->
-        <exclusion>
-          <groupId>org.apache.thrift</groupId>
-          <artifactId>libthrift</artifactId>
-        </exclusion>
-      </exclusions>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.flume</groupId>
-      <artifactId>flume-ng-core</artifactId>
-      <exclusions>
-        <exclusion>
-          <groupId>com.google.guava</groupId>
-          <artifactId>guava</artifactId>
-        </exclusion>
-        <exclusion>
-          <groupId>org.apache.thrift</groupId>
-          <artifactId>libthrift</artifactId>
-        </exclusion>
-      </exclusions>
-    </dependency>
-    <dependency>
-      <groupId>org.scala-lang</groupId>
-      <artifactId>scala-library</artifactId>
-    </dependency>
-    <dependency>
-      <!-- Add Guava in test scope since flume actually needs it. -->
-      <groupId>com.google.guava</groupId>
-      <artifactId>guava</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <!--
-        Netty explicitly added in test as it has been excluded from
-        Flume dependency (to avoid runtime problems when running with
-        Spark) but unit tests need it. Version of Netty on which
-        Flume 1.4.0 depends on is "3.4.0.Final" .
-      -->
-      <groupId>io.netty</groupId>
-      <artifactId>netty</artifactId>
-      <version>3.4.0.Final</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.spark</groupId>
-      <artifactId>spark-test-tags_${scala.binary.version}</artifactId>
-    </dependency>
-  </dependencies>
-  <build>
-    <outputDirectory>target/scala-${scala.binary.version}/classes</outputDirectory>
-    <testOutputDirectory>target/scala-${scala.binary.version}/test-classes</testOutputDirectory>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.avro</groupId>
-        <artifactId>avro-maven-plugin</artifactId>
-        <version>${avro.version}</version>
-        <configuration>
-          <!-- Generate the output in the same directory as the sbt-avro-plugin -->
-          <outputDirectory>${project.basedir}/target/scala-${scala.binary.version}/src_managed/main/compiled_avro</outputDirectory>
-        </configuration>
-        <executions>
-          <execution>
-            <phase>generate-sources</phase>
-            <goals>
-              <goal>idl-protocol</goal>
-            </goals>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-shade-plugin</artifactId>
-        <configuration>
-          <!-- Disable all relocations defined in the parent pom. -->
-          <relocations combine.self="override" />
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
-</project>
diff --git a/external/flume-sink/src/main/avro/sparkflume.avdl b/external/flume-sink/src/main/avro/sparkflume.avdl
deleted file mode 100644
index 8806e863ac..0000000000
--- a/external/flume-sink/src/main/avro/sparkflume.avdl
+++ /dev/null
@@ -1,40 +0,0 @@
-/**
- * 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.
- */
-
-@namespace("org.apache.spark.streaming.flume.sink")
-
-protocol SparkFlumeProtocol {
-
-  record SparkSinkEvent {
-    map<string> headers;
-    bytes body;
-  }
-
-  record EventBatch {
-    string errorMsg = ""; // If this is empty it is a valid message, else it represents an error
-    string sequenceNumber;
-    array<SparkSinkEvent> events;
-  }
-
-  EventBatch getEventBatch (int n);
-
-  void ack (string sequenceNumber);
-
-  void nack (string sequenceNumber);
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/Logging.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/Logging.scala
deleted file mode 100644
index 09d3fe91e4..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/Logging.scala
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import org.slf4j.{Logger, LoggerFactory}
-
-/**
- * Copy of the org.apache.spark.Logging for being used in the Spark Sink.
- * The org.apache.spark.Logging is not used so that all of Spark is not brought
- * in as a dependency.
- */
-private[sink] trait Logging {
-  // Make the log field transient so that objects with Logging can
-  // be serialized and used on another machine
-  @transient private var _log: Logger = null
-
-  // Method to get or create the logger for this object
-  protected def log: Logger = {
-    if (_log == null) {
-      initializeIfNecessary()
-      var className = this.getClass.getName
-      // Ignore trailing $'s in the class names for Scala objects
-      if (className.endsWith("$")) {
-        className = className.substring(0, className.length - 1)
-      }
-      _log = LoggerFactory.getLogger(className)
-    }
-    _log
-  }
-
-  // Log methods that take only a String
-  protected def logInfo(msg: => String) {
-    if (log.isInfoEnabled) log.info(msg)
-  }
-
-  protected def logDebug(msg: => String) {
-    if (log.isDebugEnabled) log.debug(msg)
-  }
-
-  protected def logTrace(msg: => String) {
-    if (log.isTraceEnabled) log.trace(msg)
-  }
-
-  protected def logWarning(msg: => String) {
-    if (log.isWarnEnabled) log.warn(msg)
-  }
-
-  protected def logError(msg: => String) {
-    if (log.isErrorEnabled) log.error(msg)
-  }
-
-  // Log methods that take Throwables (Exceptions/Errors) too
-  protected def logInfo(msg: => String, throwable: Throwable) {
-    if (log.isInfoEnabled) log.info(msg, throwable)
-  }
-
-  protected def logDebug(msg: => String, throwable: Throwable) {
-    if (log.isDebugEnabled) log.debug(msg, throwable)
-  }
-
-  protected def logTrace(msg: => String, throwable: Throwable) {
-    if (log.isTraceEnabled) log.trace(msg, throwable)
-  }
-
-  protected def logWarning(msg: => String, throwable: Throwable) {
-    if (log.isWarnEnabled) log.warn(msg, throwable)
-  }
-
-  protected def logError(msg: => String, throwable: Throwable) {
-    if (log.isErrorEnabled) log.error(msg, throwable)
-  }
-
-  protected def isTraceEnabled(): Boolean = {
-    log.isTraceEnabled
-  }
-
-  private def initializeIfNecessary() {
-    if (!Logging.initialized) {
-      Logging.initLock.synchronized {
-        if (!Logging.initialized) {
-          initializeLogging()
-        }
-      }
-    }
-  }
-
-  private def initializeLogging() {
-    Logging.initialized = true
-
-    // Force a call into slf4j to initialize it. Avoids this happening from multiple threads
-    // and triggering this: http://mailman.qos.ch/pipermail/slf4j-dev/2010-April/002956.html
-    log
-  }
-}
-
-private[sink] object Logging {
-  @volatile private var initialized = false
-  val initLock = new Object()
-  try {
-    // We use reflection here to handle the case where users remove the
-    // slf4j-to-jul bridge order to route their logs to JUL.
-    // scalastyle:off classforname
-    val bridgeClass = Class.forName("org.slf4j.bridge.SLF4JBridgeHandler")
-    // scalastyle:on classforname
-    bridgeClass.getMethod("removeHandlersForRootLogger").invoke(null)
-    val installed = bridgeClass.getMethod("isInstalled").invoke(null).asInstanceOf[Boolean]
-    if (!installed) {
-      bridgeClass.getMethod("install").invoke(null)
-    }
-  } catch {
-    case e: ClassNotFoundException => // can't log anything yet so just fail silently
-  }
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkAvroCallbackHandler.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkAvroCallbackHandler.scala
deleted file mode 100644
index 719fca0938..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkAvroCallbackHandler.scala
+++ /dev/null
@@ -1,166 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import java.util.UUID
-import java.util.concurrent.{CountDownLatch, Executors}
-import java.util.concurrent.atomic.AtomicLong
-
-import scala.collection.mutable
-
-import org.apache.flume.Channel
-
-/**
- * Class that implements the SparkFlumeProtocol, that is used by the Avro Netty Server to process
- * requests. Each getEvents, ack and nack call is forwarded to an instance of this class.
- * @param threads Number of threads to use to process requests.
- * @param channel The channel that the sink pulls events from
- * @param transactionTimeout Timeout in millis after which the transaction if not acked by Spark
- *                           is rolled back.
- */
-// Flume forces transactions to be thread-local. So each transaction *must* be committed, or
-// rolled back from the thread it was originally created in. So each getEvents call from Spark
-// creates a TransactionProcessor which runs in a new thread, in which the transaction is created
-// and events are pulled off the channel. Once the events are sent to spark,
-// that thread is blocked and the TransactionProcessor is saved in a map,
-// until an ACK or NACK comes back or the transaction times out (after the specified timeout).
-// When the response comes or a timeout is hit, the TransactionProcessor is retrieved and then
-// unblocked, at which point the transaction is committed or rolled back.
-
-private[flume] class SparkAvroCallbackHandler(val threads: Int, val channel: Channel,
-  val transactionTimeout: Int, val backOffInterval: Int) extends SparkFlumeProtocol with Logging {
-  val transactionExecutorOpt = Option(Executors.newFixedThreadPool(threads,
-    new SparkSinkThreadFactory("Spark Sink Processor Thread - %d")))
-  // Protected by `sequenceNumberToProcessor`
-  private val sequenceNumberToProcessor = mutable.HashMap[CharSequence, TransactionProcessor]()
-  // This sink will not persist sequence numbers and reuses them if it gets restarted.
-  // So it is possible to commit a transaction which may have been meant for the sink before the
-  // restart.
-  // Since the new txn may not have the same sequence number we must guard against accidentally
-  // committing a new transaction. To reduce the probability of that happening a random string is
-  // prepended to the sequence number. Does not change for life of sink
-  private val seqBase = UUID.randomUUID().toString.substring(0, 8)
-  private val seqCounter = new AtomicLong(0)
-
-  // Protected by `sequenceNumberToProcessor`
-  private var stopped = false
-
-  @volatile private var isTest = false
-  private var testLatch: CountDownLatch = null
-
-  /**
-   * Returns a bunch of events to Spark over Avro RPC.
-   * @param n Maximum number of events to return in a batch
-   * @return [[EventBatch]] instance that has a sequence number and an array of at most n events
-   */
-  override def getEventBatch(n: Int): EventBatch = {
-    logDebug("Got getEventBatch call from Spark.")
-    val sequenceNumber = seqBase + seqCounter.incrementAndGet()
-    createProcessor(sequenceNumber, n) match {
-      case Some(processor) =>
-        transactionExecutorOpt.foreach(_.submit(processor))
-        // Wait until a batch is available - will be an error if error message is non-empty
-        val batch = processor.getEventBatch
-        if (SparkSinkUtils.isErrorBatch(batch)) {
-          // Remove the processor if it is an error batch since no ACK is sent.
-          removeAndGetProcessor(sequenceNumber)
-          logWarning("Received an error batch - no events were received from channel! ")
-        }
-        batch
-      case None =>
-        new EventBatch("Spark sink has been stopped!", "", java.util.Collections.emptyList())
-    }
-  }
-
-  private def createProcessor(seq: String, n: Int): Option[TransactionProcessor] = {
-    sequenceNumberToProcessor.synchronized {
-      if (!stopped) {
-        val processor = new TransactionProcessor(
-          channel, seq, n, transactionTimeout, backOffInterval, this)
-        sequenceNumberToProcessor.put(seq, processor)
-        if (isTest) {
-          processor.countDownWhenBatchAcked(testLatch)
-        }
-        Some(processor)
-      } else {
-        None
-      }
-    }
-  }
-
-  /**
-   * Called by Spark to indicate successful commit of a batch
-   * @param sequenceNumber The sequence number of the event batch that was successful
-   */
-  override def ack(sequenceNumber: CharSequence): Void = {
-    logDebug("Received Ack for batch with sequence number: " + sequenceNumber)
-    completeTransaction(sequenceNumber, success = true)
-    null
-  }
-
-  /**
-   * Called by Spark to indicate failed commit of a batch
-   * @param sequenceNumber The sequence number of the event batch that failed
-   * @return
-   */
-  override def nack(sequenceNumber: CharSequence): Void = {
-    completeTransaction(sequenceNumber, success = false)
-    logInfo("Spark failed to commit transaction. Will reattempt events.")
-    null
-  }
-
-  /**
-   * Helper method to commit or rollback a transaction.
-   * @param sequenceNumber The sequence number of the batch that was completed
-   * @param success Whether the batch was successful or not.
-   */
-  private def completeTransaction(sequenceNumber: CharSequence, success: Boolean) {
-    removeAndGetProcessor(sequenceNumber).foreach(processor => {
-      processor.batchProcessed(success)
-    })
-  }
-
-  /**
-   * Helper method to remove the TxnProcessor for a Sequence Number. Can be used to avoid a leak.
-   * @param sequenceNumber
-   * @return An `Option` of the transaction processor for the corresponding batch. Note that this
-   *         instance is no longer tracked and the caller is responsible for that txn processor.
-   */
-  private[sink] def removeAndGetProcessor(sequenceNumber: CharSequence):
-      Option[TransactionProcessor] = {
-    sequenceNumberToProcessor.synchronized {
-      sequenceNumberToProcessor.remove(sequenceNumber.toString)
-    }
-  }
-
-  private[sink] def countDownWhenBatchAcked(latch: CountDownLatch) {
-    testLatch = latch
-    isTest = true
-  }
-
-  /**
-   * Shuts down the executor used to process transactions.
-   */
-  def shutdown() {
-    logInfo("Shutting down Spark Avro Callback Handler")
-    sequenceNumberToProcessor.synchronized {
-      stopped = true
-      sequenceNumberToProcessor.values.foreach(_.shutdown())
-    }
-    transactionExecutorOpt.foreach(_.shutdownNow())
-  }
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSink.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSink.scala
deleted file mode 100644
index 14dffb15fe..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSink.scala
+++ /dev/null
@@ -1,171 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import java.net.InetSocketAddress
-import java.util.concurrent._
-
-import org.apache.avro.ipc.NettyServer
-import org.apache.avro.ipc.specific.SpecificResponder
-import org.apache.flume.Context
-import org.apache.flume.Sink.Status
-import org.apache.flume.conf.{Configurable, ConfigurationException}
-import org.apache.flume.sink.AbstractSink
-
-/**
- * A sink that uses Avro RPC to run a server that can be polled by Spark's
- * FlumePollingInputDStream. This sink has the following configuration parameters:
- *
- * hostname - The hostname to bind to. Default: 0.0.0.0
- * port - The port to bind to. (No default - mandatory)
- * timeout - Time in seconds after which a transaction is rolled back,
- * if an ACK is not received from Spark within that time
- * threads - Number of threads to use to receive requests from Spark (Default: 10)
- *
- * This sink is unlike other Flume sinks in the sense that it does not push data,
- * instead the process method in this sink simply blocks the SinkRunner the first time it is
- * called. This sink starts up an Avro IPC server that uses the SparkFlumeProtocol.
- *
- * Each time a getEventBatch call comes, creates a transaction and reads events
- * from the channel. When enough events are read, the events are sent to the Spark receiver and
- * the thread itself is blocked and a reference to it saved off.
- *
- * When the ack for that batch is received,
- * the thread which created the transaction is is retrieved and it commits the transaction with the
- * channel from the same thread it was originally created in (since Flume transactions are
- * thread local). If a nack is received instead, the sink rolls back the transaction. If no ack
- * is received within the specified timeout, the transaction is rolled back too. If an ack comes
- * after that, it is simply ignored and the events get re-sent.
- *
- */
-
-class SparkSink extends AbstractSink with Logging with Configurable {
-
-  // Size of the pool to use for holding transaction processors.
-  private var poolSize: Integer = SparkSinkConfig.DEFAULT_THREADS
-
-  // Timeout for each transaction. If spark does not respond in this much time,
-  // rollback the transaction
-  private var transactionTimeout = SparkSinkConfig.DEFAULT_TRANSACTION_TIMEOUT
-
-  // Address info to bind on
-  private var hostname: String = SparkSinkConfig.DEFAULT_HOSTNAME
-  private var port: Int = 0
-
-  private var backOffInterval: Int = 200
-
-  // Handle to the server
-  private var serverOpt: Option[NettyServer] = None
-
-  // The handler that handles the callback from Avro
-  private var handler: Option[SparkAvroCallbackHandler] = None
-
-  // Latch that blocks off the Flume framework from wasting 1 thread.
-  private val blockingLatch = new CountDownLatch(1)
-
-  override def start() {
-    logInfo("Starting Spark Sink: " + getName + " on port: " + port + " and interface: " +
-      hostname + " with " + "pool size: " + poolSize + " and transaction timeout: " +
-      transactionTimeout + ".")
-    handler = Option(new SparkAvroCallbackHandler(poolSize, getChannel, transactionTimeout,
-      backOffInterval))
-    val responder = new SpecificResponder(classOf[SparkFlumeProtocol], handler.get)
-    // Using the constructor that takes specific thread-pools requires bringing in netty
-    // dependencies which are being excluded in the build. In practice,
-    // Netty dependencies are already available on the JVM as Flume would have pulled them in.
-    serverOpt = Option(new NettyServer(responder, new InetSocketAddress(hostname, port)))
-    serverOpt.foreach(server => {
-      logInfo("Starting Avro server for sink: " + getName)
-      server.start()
-    })
-    super.start()
-  }
-
-  override def stop() {
-    logInfo("Stopping Spark Sink: " + getName)
-    handler.foreach(callbackHandler => {
-      callbackHandler.shutdown()
-    })
-    serverOpt.foreach(server => {
-      logInfo("Stopping Avro Server for sink: " + getName)
-      server.close()
-      server.join()
-    })
-    blockingLatch.countDown()
-    super.stop()
-  }
-
-  override def configure(ctx: Context) {
-    import SparkSinkConfig._
-    hostname = ctx.getString(CONF_HOSTNAME, DEFAULT_HOSTNAME)
-    port = Option(ctx.getInteger(CONF_PORT)).
-      getOrElse(throw new ConfigurationException("The port to bind to must be specified"))
-    poolSize = ctx.getInteger(THREADS, DEFAULT_THREADS)
-    transactionTimeout = ctx.getInteger(CONF_TRANSACTION_TIMEOUT, DEFAULT_TRANSACTION_TIMEOUT)
-    backOffInterval = ctx.getInteger(CONF_BACKOFF_INTERVAL, DEFAULT_BACKOFF_INTERVAL)
-    logInfo("Configured Spark Sink with hostname: " + hostname + ", port: " + port + ", " +
-      "poolSize: " + poolSize + ", transactionTimeout: " + transactionTimeout + ", " +
-      "backoffInterval: " + backOffInterval)
-  }
-
-  override def process(): Status = {
-    // This method is called in a loop by the Flume framework - block it until the sink is
-    // stopped to save CPU resources. The sink runner will interrupt this thread when the sink is
-    // being shut down.
-    logInfo("Blocking Sink Runner, sink will continue to run..")
-    blockingLatch.await()
-    Status.BACKOFF
-  }
-
-  private[flume] def getPort(): Int = {
-    serverOpt
-      .map(_.getPort)
-      .getOrElse(
-        throw new RuntimeException("Server was not started!")
-      )
-  }
-
-  /**
-   * Pass in a [[CountDownLatch]] for testing purposes. This batch is counted down when each
-   * batch is received. The test can simply call await on this latch till the expected number of
-   * batches are received.
-   * @param latch
-   */
-  private[flume] def countdownWhenBatchReceived(latch: CountDownLatch) {
-    handler.foreach(_.countDownWhenBatchAcked(latch))
-  }
-}
-
-/**
- * Configuration parameters and their defaults.
- */
-private[flume]
-object SparkSinkConfig {
-  val THREADS = "threads"
-  val DEFAULT_THREADS = 10
-
-  val CONF_TRANSACTION_TIMEOUT = "timeout"
-  val DEFAULT_TRANSACTION_TIMEOUT = 60
-
-  val CONF_HOSTNAME = "hostname"
-  val DEFAULT_HOSTNAME = "0.0.0.0"
-
-  val CONF_PORT = "port"
-
-  val CONF_BACKOFF_INTERVAL = "backoffInterval"
-  val DEFAULT_BACKOFF_INTERVAL = 200
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkThreadFactory.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkThreadFactory.scala
deleted file mode 100644
index 845fc8debd..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkThreadFactory.scala
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import java.util.concurrent.ThreadFactory
-import java.util.concurrent.atomic.AtomicLong
-
-/**
- * Thread factory that generates daemon threads with a specified name format.
- */
-private[sink] class SparkSinkThreadFactory(nameFormat: String) extends ThreadFactory {
-
-  private val threadId = new AtomicLong()
-
-  override def newThread(r: Runnable): Thread = {
-    val t = new Thread(r, nameFormat.format(threadId.incrementAndGet()))
-    t.setDaemon(true)
-    t
-  }
-
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkUtils.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkUtils.scala
deleted file mode 100644
index 47c0e294d6..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkUtils.scala
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-private[flume] object SparkSinkUtils {
-  /**
-   * This method determines if this batch represents an error or not.
-   * @param batch - The batch to check
-   * @return - true if the batch represents an error
-   */
-  def isErrorBatch(batch: EventBatch): Boolean = {
-    !batch.getErrorMsg.toString.equals("") // If there is an error message, it is an error batch.
-  }
-}
diff --git a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/TransactionProcessor.scala b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/TransactionProcessor.scala
deleted file mode 100644
index b15c2097e5..0000000000
--- a/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/TransactionProcessor.scala
+++ /dev/null
@@ -1,252 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import java.nio.ByteBuffer
-import java.util
-import java.util.concurrent.{Callable, CountDownLatch, TimeUnit}
-
-import scala.util.control.Breaks
-
-import org.apache.flume.{Channel, Transaction}
-
-// Flume forces transactions to be thread-local (horrible, I know!)
-// So the sink basically spawns a new thread to pull the events out within a transaction.
-// The thread fills in the event batch object that is set before the thread is scheduled.
-// After filling it in, the thread waits on a condition - which is released only
-// when the success message comes back for the specific sequence number for that event batch.
-/**
- * This class represents a transaction on the Flume channel. This class runs a separate thread
- * which owns the transaction. The thread is blocked until the success call for that transaction
- * comes back with an ACK or NACK.
- * @param channel The channel from which to pull events
- * @param seqNum The sequence number to use for the transaction. Must be unique
- * @param maxBatchSize The maximum number of events to process per batch
- * @param transactionTimeout Time in seconds after which a transaction must be rolled back
- *                           without waiting for an ACK from Spark
- * @param parent The parent [[SparkAvroCallbackHandler]] instance, for reporting timeouts
- */
-private class TransactionProcessor(val channel: Channel, val seqNum: String,
-  var maxBatchSize: Int, val transactionTimeout: Int, val backOffInterval: Int,
-  val parent: SparkAvroCallbackHandler) extends Callable[Void] with Logging {
-
-  // If a real batch is not returned, we always have to return an error batch.
-  @volatile private var eventBatch: EventBatch = new EventBatch("Unknown Error", "",
-    util.Collections.emptyList())
-
-  // Synchronization primitives
-  val batchGeneratedLatch = new CountDownLatch(1)
-  val batchAckLatch = new CountDownLatch(1)
-
-  // Sanity check to ensure we don't loop like crazy
-  val totalAttemptsToRemoveFromChannel = Int.MaxValue / 2
-
-  // OK to use volatile, since the change would only make this true (otherwise it will be
-  // changed to false - we never apply a negation operation to this) - which means the transaction
-  // succeeded.
-  @volatile private var batchSuccess = false
-
-  @volatile private var stopped = false
-
-  @volatile private var isTest = false
-
-  private var testLatch: CountDownLatch = null
-
-  // The transaction that this processor would handle
-  var txOpt: Option[Transaction] = None
-
-  /**
-   * Get an event batch from the channel. This method will block until a batch of events is
-   * available from the channel. If no events are available after a large number of attempts of
-   * polling the channel, this method will return an [[EventBatch]] with a non-empty error message
-   *
-   * @return An [[EventBatch]] instance with sequence number set to seqNum, filled with a
-   *         maximum of maxBatchSize events
-   */
-  def getEventBatch: EventBatch = {
-    batchGeneratedLatch.await()
-    eventBatch
-  }
-
-  /**
-   * This method is to be called by the sink when it receives an ACK or NACK from Spark. This
-   * method is a no-op if it is called after transactionTimeout has expired since
-   * getEventBatch returned a batch of events.
-   * @param success True if an ACK was received and the transaction should be committed, else false.
-   */
-  def batchProcessed(success: Boolean) {
-    logDebug("Batch processed for sequence number: " + seqNum)
-    batchSuccess = success
-    batchAckLatch.countDown()
-  }
-
-  private[flume] def shutdown(): Unit = {
-    logDebug("Shutting down transaction processor")
-    stopped = true
-  }
-
-  /**
-   * Populates events into the event batch. If the batch cannot be populated,
-   * this method will not set the events into the event batch, but it sets an error message.
-   */
-  private def populateEvents() {
-    try {
-      txOpt = Option(channel.getTransaction)
-      if(txOpt.isEmpty) {
-        eventBatch.setErrorMsg("Something went wrong. Channel was " +
-          "unable to create a transaction!")
-      }
-      txOpt.foreach(tx => {
-        tx.begin()
-        val events = new util.ArrayList[SparkSinkEvent](maxBatchSize)
-        val loop = new Breaks
-        var gotEventsInThisTxn = false
-        var loopCounter: Int = 0
-        loop.breakable {
-          while (!stopped && events.size() < maxBatchSize
-            && loopCounter < totalAttemptsToRemoveFromChannel) {
-            loopCounter += 1
-            Option(channel.take()) match {
-              case Some(event) =>
-                events.add(new SparkSinkEvent(toCharSequenceMap(event.getHeaders),
-                  ByteBuffer.wrap(event.getBody)))
-                gotEventsInThisTxn = true
-              case None =>
-                if (!gotEventsInThisTxn && !stopped) {
-                  logDebug("Sleeping for " + backOffInterval + " millis as no events were read in" +
-                    " the current transaction")
-                  TimeUnit.MILLISECONDS.sleep(backOffInterval)
-                } else {
-                  loop.break()
-                }
-            }
-          }
-        }
-        if (!gotEventsInThisTxn && !stopped) {
-          val msg = "Tried several times, " +
-            "but did not get any events from the channel!"
-          logWarning(msg)
-          eventBatch.setErrorMsg(msg)
-        } else {
-          // At this point, the events are available, so fill them into the event batch
-          eventBatch = new EventBatch("", seqNum, events)
-        }
-      })
-    } catch {
-      case interrupted: InterruptedException =>
-        // Don't pollute logs if the InterruptedException came from this being stopped
-        if (!stopped) {
-          logWarning("Error while processing transaction.", interrupted)
-        }
-      case e: Exception =>
-        logWarning("Error while processing transaction.", e)
-        eventBatch.setErrorMsg(e.getMessage)
-        try {
-          txOpt.foreach(tx => {
-            rollbackAndClose(tx, close = true)
-          })
-        } finally {
-          txOpt = None
-        }
-    } finally {
-      batchGeneratedLatch.countDown()
-    }
-  }
-
-  /**
-   * Waits for upto transactionTimeout seconds for an ACK. If an ACK comes in
-   * this method commits the transaction with the channel. If the ACK does not come in within
-   * that time or a NACK comes in, this method rolls back the transaction.
-   */
-  private def processAckOrNack() {
-    batchAckLatch.await(transactionTimeout, TimeUnit.SECONDS)
-    txOpt.foreach(tx => {
-      if (batchSuccess) {
-        try {
-          logDebug("Committing transaction")
-          tx.commit()
-        } catch {
-          case e: Exception =>
-            logWarning("Error while attempting to commit transaction. Transaction will be rolled " +
-              "back", e)
-            rollbackAndClose(tx, close = false) // tx will be closed later anyway
-        } finally {
-          tx.close()
-          if (isTest) {
-            testLatch.countDown()
-          }
-        }
-      } else {
-        logWarning("Spark could not commit transaction, NACK received. Rolling back transaction.")
-        rollbackAndClose(tx, close = true)
-        // This might have been due to timeout or a NACK. Either way the following call does not
-        // cause issues. This is required to ensure the TransactionProcessor instance is not leaked
-        parent.removeAndGetProcessor(seqNum)
-      }
-    })
-  }
-
-  /**
-   * Helper method to rollback and optionally close a transaction
-   * @param tx The transaction to rollback
-   * @param close Whether the transaction should be closed or not after rolling back
-   */
-  private def rollbackAndClose(tx: Transaction, close: Boolean) {
-    try {
-      logWarning("Spark was unable to successfully process the events. Transaction is being " +
-        "rolled back.")
-      tx.rollback()
-    } catch {
-      case e: Exception =>
-        logError("Error rolling back transaction. Rollback may have failed!", e)
-    } finally {
-      if (close) {
-        tx.close()
-      }
-    }
-  }
-
-  /**
-   * Helper method to convert a Map[String, String] to Map[CharSequence, CharSequence]
-   * @param inMap The map to be converted
-   * @return The converted map
-   */
-  private def toCharSequenceMap(inMap: java.util.Map[String, String]): java.util.Map[CharSequence,
-    CharSequence] = {
-    val charSeqMap = new util.HashMap[CharSequence, CharSequence](inMap.size())
-    charSeqMap.putAll(inMap)
-    charSeqMap
-  }
-
-  /**
-   * When the thread is started it sets as many events as the batch size or less (if enough
-   * events aren't available) into the eventBatch and object and lets any threads waiting on the
-   * [[getEventBatch]] method to proceed. Then this thread waits for acks or nacks to come in,
-   * or for a specified timeout and commits or rolls back the transaction.
-   * @return
-   */
-  override def call(): Void = {
-    populateEvents()
-    processAckOrNack()
-    null
-  }
-
-  private[sink] def countDownWhenBatchAcked(latch: CountDownLatch) {
-    testLatch = latch
-    isTest = true
-  }
-}
diff --git a/external/flume-sink/src/test/resources/log4j.properties b/external/flume-sink/src/test/resources/log4j.properties
deleted file mode 100644
index 42df8792f1..0000000000
--- a/external/flume-sink/src/test/resources/log4j.properties
+++ /dev/null
@@ -1,28 +0,0 @@
-#
-# 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.
-#
-
-# Set everything to be logged to the file streaming/target/unit-tests.log
-log4j.rootCategory=INFO, file
-log4j.appender.file=org.apache.log4j.FileAppender
-log4j.appender.file.append=true
-log4j.appender.file.file=target/unit-tests.log
-log4j.appender.file.layout=org.apache.log4j.PatternLayout
-log4j.appender.file.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss.SSS} %t %p %c{1}: %m%n
-
-# Ignore messages below warning level from Jetty, because it's a bit verbose
-log4j.logger.org.spark-project.jetty=WARN
-
diff --git a/external/flume-sink/src/test/scala/org/apache/spark/streaming/flume/sink/SparkSinkSuite.scala b/external/flume-sink/src/test/scala/org/apache/spark/streaming/flume/sink/SparkSinkSuite.scala
deleted file mode 100644
index e8ca1e7163..0000000000
--- a/external/flume-sink/src/test/scala/org/apache/spark/streaming/flume/sink/SparkSinkSuite.scala
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * 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.streaming.flume.sink
-
-import java.net.InetSocketAddress
-import java.nio.charset.StandardCharsets
-import java.util.concurrent.{CountDownLatch, Executors, TimeUnit}
-import java.util.concurrent.atomic.AtomicInteger
-
-import scala.collection.JavaConverters._
-import scala.concurrent.{ExecutionContext, Future}
-import scala.util.{Failure, Success}
-
-import org.apache.avro.ipc.NettyTransceiver
-import org.apache.avro.ipc.specific.SpecificRequestor
-import org.apache.flume.Context
-import org.apache.flume.channel.MemoryChannel
-import org.apache.flume.event.EventBuilder
-import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory
-
-// Due to MNG-1378, there is not a way to include test dependencies transitively.
-// We cannot include Spark core tests as a dependency here because it depends on
-// Spark core main, which has too many dependencies to require here manually.
-// For this reason, we continue to use FunSuite and ignore the scalastyle checks
-// that fail if this is detected.
-// scalastyle:off
-import org.scalatest.FunSuite
-
-class SparkSinkSuite extends FunSuite {
-// scalastyle:on
-
-  val eventsPerBatch = 1000
-  val channelCapacity = 5000
-
-  test("Success with ack") {
-    val (channel, sink, latch) = initializeChannelAndSink()
-    channel.start()
-    sink.start()
-
-    putEvents(channel, eventsPerBatch)
-
-    val port = sink.getPort
-    val address = new InetSocketAddress("0.0.0.0", port)
-
-    val (transceiver, client) = getTransceiverAndClient(address, 1)(0)
-    val events = client.getEventBatch(1000)
-    client.ack(events.getSequenceNumber)
-    assert(events.getEvents.size() === 1000)
-    latch.await(1, TimeUnit.SECONDS)
-    assertChannelIsEmpty(channel)
-    sink.stop()
-    channel.stop()
-    transceiver.close()
-  }
-
-  test("Failure with nack") {
-    val (channel, sink, latch) = initializeChannelAndSink()
-    channel.start()
-    sink.start()
-    putEvents(channel, eventsPerBatch)
-
-    val port = sink.getPort
-    val address = new InetSocketAddress("0.0.0.0", port)
-
-    val (transceiver, client) = getTransceiverAndClient(address, 1)(0)
-    val events = client.getEventBatch(1000)
-    assert(events.getEvents.size() === 1000)
-    client.nack(events.getSequenceNumber)
-    latch.await(1, TimeUnit.SECONDS)
-    assert(availableChannelSlots(channel) === 4000)
-    sink.stop()
-    channel.stop()
-    transceiver.close()
-  }
-
-  test("Failure with timeout") {
-    val (channel, sink, latch) = initializeChannelAndSink(Map(SparkSinkConfig
-      .CONF_TRANSACTION_TIMEOUT -> 1.toString))
-    channel.start()
-    sink.start()
-    putEvents(channel, eventsPerBatch)
-    val port = sink.getPort
-    val address = new InetSocketAddress("0.0.0.0", port)
-
-    val (transceiver, client) = getTransceiverAndClient(address, 1)(0)
-    val events = client.getEventBatch(1000)
-    assert(events.getEvents.size() === 1000)
-    latch.await(1, TimeUnit.SECONDS)
-    assert(availableChannelSlots(channel) === 4000)
-    sink.stop()
-    channel.stop()
-    transceiver.close()
-  }
-
-  test("Multiple consumers") {
-    testMultipleConsumers(failSome = false)
-  }
-
-  test("Multiple consumers with some failures") {
-    testMultipleConsumers(failSome = true)
-  }
-
-  def testMultipleConsumers(failSome: Boolean): Unit = {
-    implicit val executorContext = ExecutionContext
-      .fromExecutorService(Executors.newFixedThreadPool(5))
-    val (channel, sink, latch) = initializeChannelAndSink(Map.empty, 5)
-    channel.start()
-    sink.start()
-    (1 to 5).foreach(_ => putEvents(channel, eventsPerBatch))
-    val port = sink.getPort
-    val address = new InetSocketAddress("0.0.0.0", port)
-    val transceiversAndClients = getTransceiverAndClient(address, 5)
-    val batchCounter = new CountDownLatch(5)
-    val counter = new AtomicInteger(0)
-    transceiversAndClients.foreach(x => {
-      Future {
-        val client = x._2
-        val events = client.getEventBatch(1000)
-        if (!failSome || counter.getAndIncrement() % 2 == 0) {
-          client.ack(events.getSequenceNumber)
-        } else {
-          client.nack(events.getSequenceNumber)
-          throw new RuntimeException("Sending NACK for failure!")
-        }
-        events
-      }.onComplete {
-        case Success(events) =>
-          assert(events.getEvents.size() === 1000)
-          batchCounter.countDown()
-        case Failure(t) =>
-          // Don't re-throw the exception, causes a nasty unnecessary stack trace on stdout
-          batchCounter.countDown()
-      }
-    })
-    batchCounter.await()
-    latch.await(1, TimeUnit.SECONDS)
-    executorContext.shutdown()
-    if(failSome) {
-      assert(availableChannelSlots(channel) === 3000)
-    } else {
-      assertChannelIsEmpty(channel)
-    }
-    sink.stop()
-    channel.stop()
-    transceiversAndClients.foreach(x => x._1.close())
-  }
-
-  private def initializeChannelAndSink(overrides: Map[String, String] = Map.empty,
-    batchCounter: Int = 1): (MemoryChannel, SparkSink, CountDownLatch) = {
-    val channel = new MemoryChannel()
-    val channelContext = new Context()
-
-    channelContext.put("capacity", channelCapacity.toString)
-    channelContext.put("transactionCapacity", 1000.toString)
-    channelContext.put("keep-alive", 0.toString)
-    channelContext.putAll(overrides.asJava)
-    channel.setName(scala.util.Random.nextString(10))
-    channel.configure(channelContext)
-
-    val sink = new SparkSink()
-    val sinkContext = new Context()
-    sinkContext.put(SparkSinkConfig.CONF_HOSTNAME, "0.0.0.0")
-    sinkContext.put(SparkSinkConfig.CONF_PORT, 0.toString)
-    sink.configure(sinkContext)
-    sink.setChannel(channel)
-    val latch = new CountDownLatch(batchCounter)
-    sink.countdownWhenBatchReceived(latch)
-    (channel, sink, latch)
-  }
-
-  private def putEvents(ch: MemoryChannel, count: Int): Unit = {
-    val tx = ch.getTransaction
-    tx.begin()
-    (1 to count).foreach(x =>
-      ch.put(EventBuilder.withBody(x.toString.getBytes(StandardCharsets.UTF_8))))
-    tx.commit()
-    tx.close()
-  }
-
-  private def getTransceiverAndClient(address: InetSocketAddress,
-    count: Int): Seq[(NettyTransceiver, SparkFlumeProtocol.Callback)] = {
-
-    (1 to count).map(_ => {
-      lazy val channelFactoryExecutor = Executors.newCachedThreadPool(
-        new SparkSinkThreadFactory("Flume Receiver Channel Thread - %d"))
-      lazy val channelFactory =
-        new NioClientSocketChannelFactory(channelFactoryExecutor, channelFactoryExecutor)
-      val transceiver = new NettyTransceiver(address, channelFactory)
-      val client = SpecificRequestor.getClient(classOf[SparkFlumeProtocol.Callback], transceiver)
-      (transceiver, client)
-    })
-  }
-
-  private def assertChannelIsEmpty(channel: MemoryChannel): Unit = {
-    assert(availableChannelSlots(channel) === channelCapacity)
-  }
-
-  private def availableChannelSlots(channel: MemoryChannel): Int = {
-    val queueRemaining = channel.getClass.getDeclaredField("queueRemaining")
-    queueRemaining.setAccessible(true)
-    val m = queueRemaining.get(channel).getClass.getDeclaredMethod("availablePermits")
-    m.invoke(queueRemaining.get(channel)).asInstanceOf[Int]
-  }
-}