Move internal accumulator into a private SparkContext method

Author: Feynman Liang

core/src/main/scala/org/apache/spark/SparkContext.scala

@@ -1233,13 +1233,26 @@ class SparkContext(config: SparkConf) extends Logging with ExecutorAllocationCli
    * in the Spark UI. Tasks can "add" values to the accumulator using the `+=` method. Only the
    * driver can access the accumulator's `value`.
    */
-  def accumulator[T](initialValue: T, name: String, internal: Boolean = false)(
-      implicit param: AccumulatorParam[T]): Accumulator[T] = {
+  def accumulator[T](initialValue: T, name: String)(implicit param: AccumulatorParam[T])
+  : Accumulator[T] = {
     val acc = new Accumulator(initialValue, param, Some(name))
     cleaner.foreach(_.registerAccumulatorForCleanup(acc))
     acc
   }
 
+  /**
+   * Create an [[org.apache.spark.Accumulator]] variable of a given type, with a name for display
+   * in the Spark UI, and which reports its values to the driver via heartbeats. Tasks can "add"
+   * values to the accumulator using the `+=` method. Only the driver can access the accumulator's
+   * `value`.
+   */
+  private[spark] def internalAccumulator[T](initialValue: T, name: String)(
+    implicit param: AccumulatorParam[T]): Accumulator[T] = {
+    val acc = new Accumulator(initialValue, param, Some(name), true)
+    cleaner.foreach(_.registerAccumulatorForCleanup(acc))
+    acc
+  }
+
   /**
    * Create an [[org.apache.spark.Accumulable]] shared variable, to which tasks can add values
    * with `+=`. Only the driver can access the accumuable's `value`.

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkPlan.scala

@@ -52,7 +52,7 @@ abstract class SparkPlan extends QueryPlan[SparkPlan] with Logging with Serializ
   protected def sparkContext = sqlContext.sparkContext
 
   protected val metricToAccumulator = Map(
-    "numTuples"->sparkContext.accumulator(0L, "number of tuples", internal = true))
+    "numTuples"->sparkContext.internalAccumulator(0L, "number of tuples"))
 
   // sqlContext will be null when we are being deserialized on the slaves.  In this instance
   // the value of codegenEnabled will be set by the desserializer after the constructor has run.