[SPARK-23430][WebUI]ApiHelper.COLUMN_TO_INDEX should match headers of the task table

core/src/main/scala/org/apache/spark/status/storeTypes.scala

@@ -113,6 +113,7 @@ private[spark] object TaskIndexNames {
   final val EXEC_RUN_TIME = "ert"
   final val GC_TIME = "gc"
   final val GETTING_RESULT_TIME = "grt"
+  final val HOST = "host"
   final val INPUT_RECORDS = "ir"
   final val INPUT_SIZE = "is"
   final val LAUNCH_TIME = "lt"
@@ -165,6 +166,7 @@ private[spark] class TaskDataWrapper(
     val duration: Long,
     @KVIndexParam(value = TaskIndexNames.EXECUTOR, parent = TaskIndexNames.STAGE)
     val executorId: String,
+    @KVIndexParam(value = TaskIndexNames.HOST, parent = TaskIndexNames.STAGE)
     val host: String,
     @KVIndexParam(value = TaskIndexNames.STATUS, parent = TaskIndexNames.STAGE)
     val status: String,

core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala

@@ -961,16 +961,17 @@ private[ui] class TaskPagedTable(
   }
 }
 
-private object ApiHelper {
+private[ui] object ApiHelper {
 
 
-  private val COLUMN_TO_INDEX = Map(
+  private[ui] val COLUMN_TO_INDEX = Map(
     "ID" -> null.asInstanceOf[String],
     "Index" -> TaskIndexNames.TASK_INDEX,
     "Attempt" -> TaskIndexNames.ATTEMPT,
     "Status" -> TaskIndexNames.STATUS,
     "Locality Level" -> TaskIndexNames.LOCALITY,
-    "Executor ID / Host" -> TaskIndexNames.EXECUTOR,
+    "Executor ID" -> TaskIndexNames.EXECUTOR,
+    "Host" -> TaskIndexNames.HOST,
     "Launch Time" -> TaskIndexNames.LAUNCH_TIME,
     "Duration" -> TaskIndexNames.DURATION,
     "Scheduler Delay" -> TaskIndexNames.SCHEDULER_DELAY,

core/src/test/scala/org/apache/spark/ui/StagePageSuite.scala

@@ -28,8 +28,9 @@ import org.apache.spark._
 import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.scheduler._
 import org.apache.spark.status.AppStatusStore
+import org.apache.spark.status.api.v1.{AccumulableInfo => UIAccumulableInfo, StageData, StageStatus}
 import org.apache.spark.status.config._
-import org.apache.spark.ui.jobs.{StagePage, StagesTab}
+import org.apache.spark.ui.jobs.{ApiHelper, StagePage, StagesTab, TaskPagedTable}
 
 class StagePageSuite extends SparkFunSuite with LocalSparkContext {
 
@@ -47,6 +48,66 @@ class StagePageSuite extends SparkFunSuite with LocalSparkContext {
     assert(html.contains(s"<td>$peakExecutionMemory.0 b</td>" * 5))
   }
 
+  test("ApiHelper.COLUMN_TO_INDEX should match headers of the task table") {
+    val conf = new SparkConf(false).set(LIVE_ENTITY_UPDATE_PERIOD, 0L)
+    val statusStore = AppStatusStore.createLiveStore(conf)
+    try {
+      val stageData = new StageData(
+        status = StageStatus.ACTIVE,
+        stageId = 1,
+        attemptId = 1,
+        numTasks = 1,
+        numActiveTasks = 1,
+        numCompleteTasks = 1,
+        numFailedTasks = 1,
+        numKilledTasks = 1,
+        numCompletedIndices = 1,
+
+        executorRunTime = 1L,
+        executorCpuTime = 1L,
+        submissionTime = None,
+        firstTaskLaunchedTime = None,
+        completionTime = None,
+        failureReason = None,
+
+        inputBytes = 1L,
+        inputRecords = 1L,
+        outputBytes = 1L,
+        outputRecords = 1L,
+        shuffleReadBytes = 1L,
+        shuffleReadRecords = 1L,
+        shuffleWriteBytes = 1L,
+        shuffleWriteRecords = 1L,
+        memoryBytesSpilled = 1L,
+        diskBytesSpilled = 1L,
+
+        name = "stage1",
+        description = Some("description"),
+        details = "detail",
+        schedulingPool = "pool1",
+
+        rddIds = Seq(1),
+        accumulatorUpdates = Seq(new UIAccumulableInfo(0L, "acc", None, "value")),
+        tasks = None,
+        executorSummary = None,
+        killedTasksSummary = Map.empty
+      )
+      val taskTable = new TaskPagedTable(
+        stageData,
+        basePath = "/a/b/c",
+        currentTime = 0,
+        pageSize = 10,
+        sortColumn = "Index",
+        desc = false,
+        store = statusStore
+      )
+      val columnNames = (taskTable.headers \ "th" \ "a").map(_.child(1).text).toSet
+      assert(columnNames === ApiHelper.COLUMN_TO_INDEX.keySet)
+    } finally {
+      statusStore.close()
+    }
+  }
+
   /**
    * Render a stage page started with the given conf and return the HTML.
    * This also runs a dummy stage to populate the page with useful content.