adding host as an index

Author: attilapiros

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

@@ -109,6 +109,7 @@ private[spark] object TaskIndexNames {
   final val DURATION = "dur"
   final val ERROR = "err"
   final val EXECUTOR = "exe"
+  final val HOST = "hst"
   final val EXEC_CPU_TIME = "ect"
   final val EXEC_RUN_TIME = "ert"
   final val GC_TIME = "gc"
@@ -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

@@ -999,7 +999,7 @@ private object ApiHelper {
     HEADER_STATUS -> TaskIndexNames.STATUS,
     HEADER_LOCALITY -> TaskIndexNames.LOCALITY,
     HEADER_EXECUTOR -> TaskIndexNames.EXECUTOR,
-    HEADER_HOST -> TaskIndexNames.EXECUTOR,
+    HEADER_HOST -> TaskIndexNames.HOST,
     HEADER_LAUNCH_TIME -> TaskIndexNames.LAUNCH_TIME,
     HEADER_DURATION -> TaskIndexNames.DURATION,
     HEADER_SCHEDULER_DELAY -> TaskIndexNames.SCHEDULER_DELAY,