[SPARK-8015] [FLUME] Remove Guava dependency from flume-sink.

The minimal change would be to disable shading of Guava in the module,
and rely on the transitive dependency from other libraries instead. But
since Guava's use is so localized, I think it's better to just not use
it instead, so I replaced that code and removed all traces of Guava from
the module's build.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #6555 from vanzin/SPARK-8015 and squashes the following commits:

c0ceea8 [Marcelo Vanzin] Add comments about dependency management.
c38228d [Marcelo Vanzin] Add guava dep in test scope.
b7a0349 [Marcelo Vanzin] Add libthrift exclusion.
6e0942d [Marcelo Vanzin] Add comment in pom.
2d79260 [Marcelo Vanzin] [SPARK-8015] [flume] Remove Guava dependency from flume-sink.

3 files changed, 38 insertions, 7 deletions

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
index fd01807fc3..dc2a4ab138 100644
--- 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
@@ -21,7 +21,6 @@ import java.util.concurrent.atomic.AtomicLong
 
 import scala.collection.mutable
 
-import com.google.common.util.concurrent.ThreadFactoryBuilder
 import org.apache.flume.Channel
 import org.apache.commons.lang3.RandomStringUtils
 
@@ -45,8 +44,7 @@ import org.apache.commons.lang3.RandomStringUtils
 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 ThreadFactoryBuilder().setDaemon(true)
-      .setNameFormat("Spark Sink Processor Thread - %d").build()))
+    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.
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
new file mode 100644
index 0000000000..845fc8debd
--- /dev/null
+++ b/external/flume-sink/src/main/scala/org/apache/spark/streaming/flume/sink/SparkSinkThreadFactory.scala
@@ -0,0 +1,35 @@
+/*
+ * 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/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
index 605b3fe710..fa43629d49 100644
--- 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
@@ -24,7 +24,6 @@ import scala.collection.JavaConversions._
 import scala.concurrent.{ExecutionContext, Future}
 import scala.util.{Failure, Success}
 
-import com.google.common.util.concurrent.ThreadFactoryBuilder
 import org.apache.avro.ipc.NettyTransceiver
 import org.apache.avro.ipc.specific.SpecificRequestor
 import org.apache.flume.Context
@@ -194,9 +193,8 @@ class SparkSinkSuite extends FunSuite {
     count: Int): Seq[(NettyTransceiver, SparkFlumeProtocol.Callback)] = {
 
     (1 to count).map(_ => {
-      lazy val channelFactoryExecutor =
-        Executors.newCachedThreadPool(new ThreadFactoryBuilder().setDaemon(true).
-          setNameFormat("Flume Receiver Channel Thread - %d").build())
+      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)