Remove "display" variable and assume display = name.isDefined

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

@@ -36,23 +36,20 @@ import org.apache.spark.serializer.JavaSerializer
  *
  * @param initialValue initial value of accumulator
  * @param param helper object defining how to add elements of type `R` and `T`
- * @param _name human-readable name for use in Spark's web UI
- * @param display whether to show accumulator values Spark's web UI
+ * @param name human-readable name for use in Spark's web UI
  * @tparam R the full accumulated data (result type)
  * @tparam T partial data that can be added in
  */
 class Accumulable[R, T] (
     @transient initialValue: R,
     param: AccumulableParam[R, T],
-    _name: Option[String],
-    val display: Boolean)
+    val name: Option[String])
   extends Serializable {
 
   def this(@transient initialValue: R, param: AccumulableParam[R, T]) =
-    this(initialValue, param, None, true)
+    this(initialValue, param, None)
 
   val id: Long = Accumulators.newId
-  val name = _name.getOrElse(s"accumulator_$id")
 
   @transient private var value_ = initialValue // Current value on master
   val zero = param.zero(initialValue)  // Zero value to be passed to workers
@@ -228,9 +225,9 @@ GrowableAccumulableParam[R <% Growable[T] with TraversableOnce[T] with Serializa
  * @param param helper object defining how to add elements of type `T`
  * @tparam T result type
  */
-class Accumulator[T](@transient initialValue: T, param: AccumulatorParam[T], name: Option[String],
-    display: Boolean) extends Accumulable[T,T](initialValue, param, name, display) {
-  def this(initialValue: T, param: AccumulatorParam[T]) = this(initialValue, param, None, false)
+class Accumulator[T](@transient initialValue: T, param: AccumulatorParam[T], name: Option[String])
+    extends Accumulable[T,T](initialValue, param, name) {
+  def this(initialValue: T, param: AccumulatorParam[T]) = this(initialValue, param, None)
 }
 
 /**

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

@@ -763,7 +763,7 @@ class SparkContext(config: SparkConf) extends Logging {
    * driver can access the accumulator's `value`.
    */
   def accumulator[T](initialValue: T, name: String)(implicit param: AccumulatorParam[T]) = {
-    new Accumulator(initialValue, param, Some(name), true)
+    new Accumulator(initialValue, param, Some(name))
   }
 
   /**
@@ -783,7 +783,7 @@ class SparkContext(config: SparkConf) extends Logging {
    * @tparam R type that can be added to the accumulator
    */
   def accumulable[T, R](initialValue: T, name: String)(implicit param: AccumulableParam[T, R]) =
-    new Accumulable(initialValue, param, Some(name), true)
+    new Accumulable(initialValue, param, Some(name))
 
   /**
    * Create an accumulator from a "mutable collection" type.

core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala

@@ -819,12 +819,12 @@ class DAGScheduler(
           Accumulators.add(event.accumUpdates) // TODO: do this only if task wasn't resubmitted
           event.accumUpdates.foreach { case (id, partialValue) =>
             val acc = Accumulators.originals(id).asInstanceOf[Accumulable[Any, Any]]
-            val name = acc.name
             // To avoid UI cruft, ignore cases where value wasn't updated
-            if (partialValue != acc.zero) {
+            if (acc.name.isDefined && partialValue != acc.zero) {
+              val name = acc.name.get
               val stringPartialValue = "%s".format(partialValue)
               val stringValue = "%s".format(acc.value)
-              stageToInfos(stage).accumulables(id) = AccumulableInfo(id, acc.name, stringValue)
+              stageToInfos(stage).accumulables(id) = AccumulableInfo(id, name, stringValue)
               event.taskInfo.accumulables +=
                 AccumulableInfo(id, name, Some(stringPartialValue), stringValue)
             }