[SPARK-13186][STREAMING] migrate away from SynchronizedMap

trait SynchronizedMap in package mutable is deprecated: Synchronization via traits is deprecated as it is inherently unreliable. Change to java.util.concurrent.ConcurrentHashMap instead.

Author: Huaxin Gao <huaxing@us.ibm.com>

Closes #11250 from huaxingao/spark__13186.

3 files changed, 27 insertions, 18 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
index 1c2325409b..a25dada5ea 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/FileInputDStream.scala
@@ -117,7 +117,7 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
   // Map of batch-time to selected file info for the remembered batches
   // This is a concurrent map because it's also accessed in unit tests
   @transient private[streaming] var batchTimeToSelectedFiles =
-    new mutable.HashMap[Time, Array[String]] with mutable.SynchronizedMap[Time, Array[String]]
+    new mutable.HashMap[Time, Array[String]]
 
   // Set of files that were selected in the remembered batches
   @transient private var recentlySelectedFiles = new mutable.HashSet[String]()
@@ -148,7 +148,9 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
     // Find new files
     val newFiles = findNewFiles(validTime.milliseconds)
     logInfo("New files at time " + validTime + ":\n" + newFiles.mkString("\n"))
-    batchTimeToSelectedFiles += ((validTime, newFiles))
+    batchTimeToSelectedFiles.synchronized {
+      batchTimeToSelectedFiles += ((validTime, newFiles))
+    }
     recentlySelectedFiles ++= newFiles
     val rdds = Some(filesToRDD(newFiles))
     // Copy newFiles to immutable.List to prevent from being modified by the user
@@ -162,14 +164,15 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
 
   /** Clear the old time-to-files mappings along with old RDDs */
   protected[streaming] override def clearMetadata(time: Time) {
-    super.clearMetadata(time)
-    val oldFiles = batchTimeToSelectedFiles.filter(_._1 < (time - rememberDuration))
-    batchTimeToSelectedFiles --= oldFiles.keys
-    recentlySelectedFiles --= oldFiles.values.flatten
-    logInfo("Cleared " + oldFiles.size + " old files that were older than " +
-      (time - rememberDuration) + ": " + oldFiles.keys.mkString(", "))
-    logDebug("Cleared files are:\n" +
-      oldFiles.map(p => (p._1, p._2.mkString(", "))).mkString("\n"))
+    batchTimeToSelectedFiles.synchronized {
+      val oldFiles = batchTimeToSelectedFiles.filter(_._1 < (time - rememberDuration))
+      batchTimeToSelectedFiles --= oldFiles.keys
+      recentlySelectedFiles --= oldFiles.values.flatten
+      logInfo("Cleared " + oldFiles.size + " old files that were older than " +
+        (time - rememberDuration) + ": " + oldFiles.keys.mkString(", "))
+      logDebug("Cleared files are:\n" +
+        oldFiles.map(p => (p._1, p._2.mkString(", "))).mkString("\n"))
+    }
     // Delete file mod times that weren't accessed in the last round of getting new files
     fileToModTime.clearOldValues(lastNewFileFindingTime - 1)
   }
@@ -307,8 +310,7 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
     logDebug(this.getClass().getSimpleName + ".readObject used")
     ois.defaultReadObject()
     generatedRDDs = new mutable.HashMap[Time, RDD[(K, V)]]()
-    batchTimeToSelectedFiles =
-      new mutable.HashMap[Time, Array[String]] with mutable.SynchronizedMap[Time, Array[String]]
+    batchTimeToSelectedFiles = new mutable.HashMap[Time, Array[String]]
     recentlySelectedFiles = new mutable.HashSet[String]()
     fileToModTime = new TimeStampedHashMap[String, Long](true)
   }
@@ -324,7 +326,7 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
 
     override def update(time: Time) {
       hadoopFiles.clear()
-      hadoopFiles ++= batchTimeToSelectedFiles
+      batchTimeToSelectedFiles.synchronized { hadoopFiles ++= batchTimeToSelectedFiles }
     }
 
     override def cleanup(time: Time) { }
@@ -335,7 +337,7 @@ class FileInputDStream[K, V, F <: NewInputFormat[K, V]](
           // Restore the metadata in both files and generatedRDDs
           logInfo("Restoring files for time " + t + " - " +
             f.mkString("[", ", ", "]") )
-          batchTimeToSelectedFiles += ((t, f))
+          batchTimeToSelectedFiles.synchronized { batchTimeToSelectedFiles += ((t, f)) }
           recentlySelectedFiles ++= f
           generatedRDDs += ((t, filesToRDD(f)))
         }
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
index 1f0245a397..dada495843 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
@@ -613,7 +613,8 @@ class CheckpointSuite extends TestSuiteBase with DStreamCheckpointTester
     def recordedFiles(ssc: StreamingContext): Seq[Int] = {
       val fileInputDStream =
         ssc.graph.getInputStreams().head.asInstanceOf[FileInputDStream[_, _, _]]
-      val filenames = fileInputDStream.batchTimeToSelectedFiles.values.flatten
+      val filenames = fileInputDStream.batchTimeToSelectedFiles.synchronized
+         { fileInputDStream.batchTimeToSelectedFiles.values.flatten }
       filenames.map(_.split(File.separator).last.toInt).toSeq.sorted
     }
 
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
index 66f47394c7..6c60652cd6 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
@@ -270,7 +270,10 @@ class StreamingListenerSuite extends TestSuiteBase with Matchers {
       }
     }
     _ssc.stop()
-    failureReasonsCollector.failureReasons.toMap
+    failureReasonsCollector.failureReasons.synchronized
+    {
+      failureReasonsCollector.failureReasons.toMap
+    }
   }
 
   /** Check if a sequence of numbers is in increasing order */
@@ -354,12 +357,15 @@ class StreamingListenerSuiteReceiver extends Receiver[Any](StorageLevel.MEMORY_O
  */
 class FailureReasonsCollector extends StreamingListener {
 
-  val failureReasons = new HashMap[Int, String] with SynchronizedMap[Int, String]
+  val failureReasons = new HashMap[Int, String]
 
   override def onOutputOperationCompleted(
       outputOperationCompleted: StreamingListenerOutputOperationCompleted): Unit = {
     outputOperationCompleted.outputOperationInfo.failureReason.foreach { f =>
-      failureReasons(outputOperationCompleted.outputOperationInfo.id) = f
+      failureReasons.synchronized
+      {
+        failureReasons(outputOperationCompleted.outputOperationInfo.id) = f
+      }
     }
   }
 }