[SPARK-7296] Add timeline visualization for stages in the UI.

This PR builds on #2342 by adding a timeline view for the Stage page,
showing how tasks spend their time.

With this timeline, we can understand following things of a Stage.

* When/where each task ran
* Total duration of each task
* Proportion of the time each task spends

Also, this timeline view can scrollable and zoomable.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #5843 from sarutak/stage-page-timeline and squashes the following commits:

4ba9604 [Kousuke Saruta] Fixed the order of legends
16bb552 [Kousuke Saruta] Removed border of legend area
2e5d605 [Kousuke Saruta] Modified warning message
16cb2e6 [Kousuke Saruta] Merge branch 'master' of https://github.com/apache/spark into stage-page-timeline
7ae328f [Kousuke Saruta] Modified code style
d5f794a [Kousuke Saruta] Fixed performance issues more
64e6642 [Kousuke Saruta] Merge branch 'master' of https://github.com/apache/spark into stage-page-timeline
e4a3354 [Kousuke Saruta] minor code style change
878e3b8 [Kousuke Saruta] Fixed a bug that tooltip remains
b9d8f1b [Kousuke Saruta] Fixed performance issue
ac8842b [Kousuke Saruta] Fixed layout
2319739 [Kousuke Saruta] Modified appearances more
81903ab [Kousuke Saruta] Modified appearances
a79dcc3 [Kousuke Saruta] Modified appearance
55a390c [Kousuke Saruta] Ignored scalastyle for a line-comment
29eae3e [Kousuke Saruta] limited to longest 1000 tasks
2a9e376 [Kousuke Saruta] Minor cleanup
385b6d2 [Kousuke Saruta] Added link feature
ba1ac3e [Kousuke Saruta] Fixed style
2ae8520 [Kousuke Saruta] Updated bootstrap-tooltip.js from 2.2.2 to 2.3.2
af430f1 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into stage-page-timeline
e694b8e [Kousuke Saruta] Added timeline view to StagePage
8f6610c [Kousuke Saruta] Fixed conflict
b587cf2 [Kousuke Saruta] initial commit
11fe67d [Kousuke Saruta] Fixed conflict
79ac03d [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
a91abd3 [Kousuke Saruta] Merge branch 'master' of https://github.com/apache/spark into timeline-viewer-feature
ef34a5b [Kousuke Saruta] Implement tooltip using bootstrap
b09d0c5 [Kousuke Saruta] Move `stroke` and `fill` attribute of rect elements to css
d3c63c8 [Kousuke Saruta] Fixed a little bit bugs
a36291b [Kousuke Saruta] Merge branch 'master' of https://github.com/apache/spark into timeline-viewer-feature
28714b6 [Kousuke Saruta] Fixed highlight issue
0dc4278 [Kousuke Saruta] Addressed most of Patrics's feedbacks
8110acf [Kousuke Saruta] Added scroll limit to Job timeline
974a64a [Kousuke Saruta] Removed unused function
ee7a7f0 [Kousuke Saruta] Refactored
6a91872 [Kousuke Saruta] Temporary commit
6693f34 [Kousuke Saruta] Added link to job/stage box in the timeline in order to move to corresponding row when we click
8f88222 [Kousuke Saruta] Added job/stage description
aeed4b1 [Kousuke Saruta] Removed stage timeline
fc1696c [Kousuke Saruta] Merge branch 'timeline-viewer-feature' of github.com:sarutak/spark into timeline-viewer-feature
999ccd4 [Kousuke Saruta] Improved scalability
0fc6a31 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
19815ae [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
68b7540 [Kousuke Saruta] Merge branch 'timeline-viewer-feature' of github.com:sarutak/spark into timeline-viewer-feature
52b5f0b [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
dec85db [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
fcdab7d [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
dab7cc1 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
09cce97 [Kousuke Saruta] Cleanuped
16f82cf [Kousuke Saruta] Cleanuped
9fb522e [Kousuke Saruta] Cleanuped
d05f2c2 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into timeline-viewer-feature
e85e9aa [Kousuke Saruta] Cleanup: Added TimelineViewUtils.scala
a76e569 [Kousuke Saruta] Removed unused setting in timeline-view.css
5ce1b21 [Kousuke Saruta] Added vis.min.js, vis.min.css and vis.map to .rat-exclude
082f709 [Kousuke Saruta] Added Timeline-View feature for Applications, Jobs and Stages

4 files changed, 348 insertions, 10 deletions

diff --git a/core/src/main/resources/org/apache/spark/ui/static/timeline-view.css b/core/src/main/resources/org/apache/spark/ui/static/timeline-view.css
index d1e6d462b8..0f400461c5 100644
--- a/core/src/main/resources/org/apache/spark/ui/static/timeline-view.css
+++ b/core/src/main/resources/org/apache/spark/ui/static/timeline-view.css
@@ -24,6 +24,65 @@ div#application-timeline, div#job-timeline {
   margin-top: 5px;
 }
 
+#task-assignment-timeline div.legend-area {
+  width: 574px;
+}
+
+#task-assignment-timeline .legend-area > svg {
+  width: 100%;
+  height: 55px;
+}
+
+#task-assignment-timeline div.item.range {
+  padding: 0px;
+  height: 26px;
+  border-width: 0;
+}
+
+.task-assignment-timeline-content {
+  width: 100%;
+}
+
+.task-assignment-timeline-duration-bar {
+  width: 100%;
+  height: 26px;
+}
+
+rect.scheduler-delay-proportion {
+  fill: #80B1D3;
+  stroke: #6B94B0;
+}
+
+rect.deserialization-time-proportion {
+  fill: #FB8072;
+  stroke: #D26B5F;
+}
+
+rect.shuffle-read-time-proportion {
+  fill: #FDB462;
+  stroke: #D39651;
+}
+
+rect.executor-runtime-proportion {
+  fill: #B3DE69;
+  stroke: #95B957;
+}
+
+rect.shuffle-write-time-proportion {
+  fill: #FFED6F;
+  stroke: #D5C65C;
+}
+
+rect.serialization-time-proportion {
+  fill: #BC80BD;
+  stroke: #9D6B9E;
+}
+
+rect.getting-result-time-proportion {
+  fill: #8DD3C7;
+  stroke: #75B0A6;
+}
+
 .vis.timeline {
   line-height: 14px;
 }
@@ -178,6 +237,10 @@ tr.corresponding-item-hover > td, tr.corresponding-item-hover > th {
   display: none;
 }
 
+#task-assignment-timeline.collapsed {
+  display: none;
+}
+
 .control-panel {
   margin-bottom: 5px;
 }
@@ -186,7 +249,8 @@ tr.corresponding-item-hover > td, tr.corresponding-item-hover > th {
   margin: 0;
 }
 
-span.expand-application-timeline, span.expand-job-timeline {
+span.expand-application-timeline, span.expand-job-timeline,
+span.expand-task-assignment-timeline {
   cursor: pointer;
 }
 
diff --git a/core/src/main/resources/org/apache/spark/ui/static/timeline-view.js b/core/src/main/resources/org/apache/spark/ui/static/timeline-view.js
index 558beb8a58..e1150359bc 100644
--- a/core/src/main/resources/org/apache/spark/ui/static/timeline-view.js
+++ b/core/src/main/resources/org/apache/spark/ui/static/timeline-view.js
@@ -133,6 +133,73 @@ function drawJobTimeline(groupArray, eventObjArray, startTime) {
   });
 }
 
+function drawTaskAssignmentTimeline(groupArray, eventObjArray, minLaunchTime, zoomMax) {
+  var groups = new vis.DataSet(groupArray);
+  var items = new vis.DataSet(eventObjArray);
+  var container = $("#task-assignment-timeline")[0]
+  var options = {
+    groupOrder: function(a, b) {
+      return a.value - b.value
+    },
+    editable: false,
+    align: 'left',
+    selectable: false,
+    showCurrentTime: false,
+    min: minLaunchTime,
+    zoomable: false,
+    zoomMax: zoomMax
+  };
+
+  var taskTimeline = new vis.Timeline(container)
+  taskTimeline.setOptions(options);
+  taskTimeline.setGroups(groups);
+  taskTimeline.setItems(items);
+
+  taskTimeline.on("rangechange", function(prop) {
+    if (currentDisplayedTooltip !== null) {
+      $(currentDisplayedTooltip).tooltip("hide");
+    }
+  });
+
+  function getTaskIdxAndAttempt(selector) {
+    var taskIdxText = $(selector).attr("data-title");
+    var taskIdxAndAttempt = taskIdxText.match("Task (\\d+) \\(attempt (\\d+)");
+    var taskIdx = taskIdxAndAttempt[1];
+    var taskAttempt = taskIdxAndAttempt[2];
+    return taskIdx + "-" + taskAttempt;
+  }
+
+  // If we zoom up and a box moves away when the corresponding tooltip is shown,
+  // the tooltip can be remain.
+  // So, we need to hide tooltips using another mechanism.
+  var currentDisplayedTooltip = null;
+
+  $("#task-assignment-timeline").on({
+    "mouseenter": function() {
+      var taskIdxAndAttempt = getTaskIdxAndAttempt(this);
+      $("#task-" + taskIdxAndAttempt).addClass("corresponding-item-hover");
+      $(this).tooltip("show");
+      currentDisplayedTooltip = this;
+    },
+    "mouseleave" : function() {
+      var taskIdxAndAttempt = getTaskIdxAndAttempt(this);
+      $("#task-" + taskIdxAndAttempt).removeClass("corresponding-item-hover");
+      $(this).tooltip("hide");
+      currentDisplayedTooltip = null;
+    }
+  }, ".task-assignment-timeline-content");
+
+  setupZoomable('#task-assignment-timeline-zoom-lock', taskTimeline);
+
+  $("span.expand-task-assignment-timeline").click(function() {
+    $("#task-assignment-timeline").toggleClass('collapsed');
+
+     // Switch the class of the arrow from open to closed.
+    $(this).find('.expand-task-assignment-timeline-arrow').toggleClass('arrow-open');
+    $(this).find('.expand-task-assignment-timeline-arrow').toggleClass('arrow-closed');
+  });
+}
+
 function setupExecutorEventAction() {
   $(".item.box.executor").each(function () {
     $(this).hover(
@@ -147,7 +214,7 @@ function setupExecutorEventAction() {
 }
 
 function setupZoomable(id, timeline) {
-  $(id + '>input[type="checkbox"]').click(function() {
+  $(id + ' > input[type="checkbox"]').click(function() {
     if (this.checked) {
       timeline.setOptions({zoomable: true});
     } else {
@@ -155,7 +222,7 @@ function setupZoomable(id, timeline) {
     }
   });
 
-  $(id + ">span").click(function() {
+  $(id + " > span").click(function() {
     $(this).parent().find('input:checkbox').trigger('click');
   });
 }
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala b/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
index 8f7b1c2f09..1a75ea6250 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala
@@ -20,6 +20,7 @@ package org.apache.spark.ui.jobs
 import java.util.Date
 import javax.servlet.http.HttpServletRequest
 
+import scala.collection.mutable.HashSet
 import scala.xml.{Elem, Node, Unparsed}
 
 import org.apache.commons.lang3.StringEscapeUtils
@@ -36,6 +37,35 @@ private[ui] class StagePage(parent: StagesTab) extends WebUIPage("stage") {
   private val progressListener = parent.progressListener
   private val operationGraphListener = parent.operationGraphListener
 
+  private val TIMELINE_LEGEND = {
+    <div class="legend-area">
+      <svg>
+        {
+          val legendPairs = List(("scheduler-delay-proportion", "Scheduler Delay"),
+            ("deserialization-time-proportion", "Task Deserialization Time"),
+            ("shuffle-read-time-proportion", "Shuffle Read Time"),
+            ("executor-runtime-proportion", "Executor Computing Time"),
+            ("shuffle-write-time-proportion", "Shuffle Write Time"),
+            ("serialization-time-proportion", "Result Serialization TIme"),
+            ("getting-result-time-proportion", "Getting Result Time"))
+
+          legendPairs.zipWithIndex.map {
+            case ((classAttr, name), index) =>
+              <rect x={5 + (index / 3) * 210 + "px"} y={10 + (index % 3) * 15 + "px"}
+                width="10px" height="10px" class={classAttr}></rect>
+                <text x={25 + (index / 3) * 210 + "px"}
+                  y={20 + (index % 3) * 15 + "px"}>{name}</text>
+          }
+        }
+      </svg>
+    </div>
+  }
+
+  // TODO: We should consider increasing the number of this parameter over time
+  // if we find that it's okay.
+  private val MAX_TIMELINE_TASKS = parent.conf.getInt("spark.ui.timeline.tasks.maximum", 1000)
+
+
   def render(request: HttpServletRequest): Seq[Node] = {
     progressListener.synchronized {
       val parameterId = request.getParameter("id")
@@ -196,7 +226,9 @@ private[ui] class StagePage(parent: StagesTab) extends WebUIPage("stage") {
       val accumulableHeaders: Seq[String] = Seq("Accumulable", "Value")
       def accumulableRow(acc: AccumulableInfo): Elem =
         <tr><td>{acc.name}</td><td>{acc.value}</td></tr>
-      val accumulableTable = UIUtils.listingTable(accumulableHeaders, accumulableRow,
+      val accumulableTable = UIUtils.listingTable(
+        accumulableHeaders,
+        accumulableRow,
         accumulables.values.toSeq)
 
       val taskHeadersAndCssClasses: Seq[(String, String)] =
@@ -232,10 +264,17 @@ private[ui] class StagePage(parent: StagesTab) extends WebUIPage("stage") {
 
       val unzipped = taskHeadersAndCssClasses.unzip
 
+      val currentTime = System.currentTimeMillis()
       val taskTable = UIUtils.listingTable(
         unzipped._1,
-        taskRow(hasAccumulators, stageData.hasInput, stageData.hasOutput,
-          stageData.hasShuffleRead, stageData.hasShuffleWrite, stageData.hasBytesSpilled),
+        taskRow(
+          hasAccumulators,
+          stageData.hasInput,
+          stageData.hasOutput,
+          stageData.hasShuffleRead,
+          stageData.hasShuffleWrite,
+          stageData.hasBytesSpilled,
+          currentTime),
         tasks,
         headerClasses = unzipped._2)
       // Excludes tasks which failed and have incomplete metrics
@@ -460,25 +499,192 @@ private[ui] class StagePage(parent: StagesTab) extends WebUIPage("stage") {
         dagViz ++
         maybeExpandDagViz ++
         showAdditionalMetrics ++
+        makeTimeline(stageData.taskData.values.toSeq, currentTime) ++
         <h4>Summary Metrics for {numCompleted} Completed Tasks</h4> ++
         <div>{summaryTable.getOrElse("No tasks have reported metrics yet.")}</div> ++
         <h4>Aggregated Metrics by Executor</h4> ++ executorTable.toNodeSeq ++
         maybeAccumulableTable ++
         <h4>Tasks</h4> ++ taskTable
-
       UIUtils.headerSparkPage(stageHeader, content, parent, showVisualization = true)
     }
   }
 
+  def makeTimeline(tasks: Seq[TaskUIData], currentTime: Long): Seq[Node] = {
+    val executorsSet = new HashSet[(String, String)]
+    var minLaunchTime = Long.MaxValue
+    var maxFinishTime = Long.MinValue
+
+    val executorsArrayStr =
+      tasks.sortBy(-_.taskInfo.launchTime).take(MAX_TIMELINE_TASKS).map { taskUIData =>
+        val taskInfo = taskUIData.taskInfo
+        val executorId = taskInfo.executorId
+        val host = taskInfo.host
+        executorsSet += ((executorId, host))
+
+        val classNameByStatus = {
+          if (taskInfo.successful) {
+            "succeeded"
+          } else if (taskInfo.failed) {
+            "failed"
+          } else if (taskInfo.running) {
+            "running"
+          }
+        }
+
+        val launchTime = taskInfo.launchTime
+        val finishTime = if (!taskInfo.running) taskInfo.finishTime else currentTime
+        val totalExecutionTime = finishTime - launchTime
+        minLaunchTime = launchTime.min(minLaunchTime)
+        maxFinishTime = launchTime.max(maxFinishTime)
+
+        def toProportion(time: Long) = (time.toDouble / totalExecutionTime * 100).toLong
+
+        val metricsOpt = taskUIData.taskMetrics
+        val shuffleReadTime =
+          metricsOpt.flatMap(_.shuffleReadMetrics.map(_.fetchWaitTime)).getOrElse(0L)
+        val shuffleReadTimeProportion = toProportion(shuffleReadTime)
+        val shuffleWriteTime =
+          (metricsOpt.flatMap(_.shuffleWriteMetrics
+            .map(_.shuffleWriteTime)).getOrElse(0L) / 1e6).toLong
+        val shuffleWriteTimeProportion = toProportion(shuffleWriteTime)
+        val executorComputingTime = metricsOpt.map(_.executorRunTime).getOrElse(0L) -
+          shuffleReadTime - shuffleWriteTime
+        val executorComputingTimeProportion = toProportion(executorComputingTime)
+        val serializationTime = metricsOpt.map(_.resultSerializationTime).getOrElse(0L)
+        val serializationTimeProportion = toProportion(serializationTime)
+        val deserializationTime = metricsOpt.map(_.executorDeserializeTime).getOrElse(0L)
+        val deserializationTimeProportion = toProportion(deserializationTime)
+        val gettingResultTime = getGettingResultTime(taskUIData.taskInfo)
+        val gettingResultTimeProportion = toProportion(gettingResultTime)
+        val schedulerDelay = totalExecutionTime -
+          (executorComputingTime + shuffleReadTime + shuffleWriteTime +
+            serializationTime + deserializationTime + gettingResultTime)
+        val schedulerDelayProportion =
+          (100 - executorComputingTimeProportion - shuffleReadTimeProportion -
+            shuffleWriteTimeProportion - serializationTimeProportion -
+            deserializationTimeProportion - gettingResultTimeProportion)
+
+        val schedulerDelayProportionPos = 0
+        val deserializationTimeProportionPos =
+          schedulerDelayProportionPos + schedulerDelayProportion
+        val shuffleReadTimeProportionPos =
+          deserializationTimeProportionPos + deserializationTimeProportion
+        val executorRuntimeProportionPos =
+          shuffleReadTimeProportionPos + shuffleReadTimeProportion
+        val shuffleWriteTimeProportionPos =
+          executorRuntimeProportionPos + executorComputingTimeProportion
+        val serializationTimeProportionPos =
+          shuffleWriteTimeProportionPos + shuffleWriteTimeProportion
+        val gettingResultTimeProportionPos =
+          serializationTimeProportionPos + serializationTimeProportion
+
+        val index = taskInfo.index
+        val attempt = taskInfo.attempt
+        val timelineObject =
+          s"""
+             {
+               'className': 'task task-assignment-timeline-object $classNameByStatus',
+               'group': '$executorId',
+               'content': '<div class="task-assignment-timeline-content"' +
+                 'data-toggle="tooltip" data-placement="top"' +
+                 'data-html="true" data-container="body"' +
+                 'data-title="${s"Task " + index + " (attempt " + attempt + ")"}<br>' +
+                 'Status: ${taskInfo.status}<br>' +
+                 'Launch Time: ${UIUtils.formatDate(new Date(launchTime))}' +
+                 '${
+                     if (!taskInfo.running) {
+                       s"""<br>Finish Time: ${UIUtils.formatDate(new Date(finishTime))}"""
+                     } else {
+                        ""
+                      }
+                   }' +
+                 '<br>Scheduler Delay: $schedulerDelay ms' +
+                 '<br>Task Deserialization Time: ${UIUtils.formatDuration(deserializationTime)}' +
+                 '<br>Shuffle Read Time: ${UIUtils.formatDuration(shuffleReadTime)}' +
+                 '<br>Executor Computing Time: ${UIUtils.formatDuration(executorComputingTime)}' +
+                 '<br>Shuffle Write Time: ${UIUtils.formatDuration(shuffleWriteTime)}' +
+                 '<br>Result Serialization Time: ${UIUtils.formatDuration(serializationTime)}' +
+                 '<br>Getting Result Time: ${UIUtils.formatDuration(gettingResultTime)}">' +
+                 '<svg class="task-assignment-timeline-duration-bar">' +
+                 '<rect class="scheduler-delay-proportion" ' +
+                   'x="$schedulerDelayProportionPos%" y="0px" height="26px"' +
+                   'width="$schedulerDelayProportion%""></rect>' +
+                 '<rect class="deserialization-time-proportion" '+
+                   'x="$deserializationTimeProportionPos%" y="0px" height="26px"' +
+                   'width="$deserializationTimeProportion%"></rect>' +
+                 '<rect class="shuffle-read-time-proportion" ' +
+                   'x="$shuffleReadTimeProportionPos%" y="0px" height="26px"' +
+                   'width="$shuffleReadTimeProportion%"></rect>' +
+                 '<rect class="executor-runtime-proportion" ' +
+                   'x="$executorRuntimeProportionPos%" y="0px" height="26px"' +
+                   'width="$executorComputingTimeProportion%"></rect>' +
+                 '<rect class="shuffle-write-time-proportion" ' +
+                   'x="$shuffleWriteTimeProportionPos%" y="0px" height="26px"' +
+                   'width="$shuffleWriteTimeProportion%"></rect>' +
+                 '<rect class="serialization-time-proportion" ' +
+                   'x="$serializationTimeProportionPos%" y="0px" height="26px"' +
+                   'width="$serializationTimeProportion%"></rect>' +
+                 '<rect class="getting-result-time-proportion" ' +
+                   'x="$gettingResultTimeProportionPos%" y="0px" height="26px"' +
+                   'width="$gettingResultTimeProportion%"></rect></svg>',
+               'start': new Date($launchTime),
+               'end': new Date($finishTime)
+             }
+           """
+        timelineObject
+      }.mkString("[", ",", "]")
+
+    val groupArrayStr = executorsSet.map {
+      case (executorId, host) =>
+        s"""
+            {
+              'id': '$executorId',
+              'content': '$executorId / $host',
+            }
+          """
+    }.mkString("[", ",", "]")
+
+    val maxZoom = maxFinishTime - minLaunchTime
+    <span class="expand-task-assignment-timeline">
+      <span class="expand-task-assignment-timeline-arrow arrow-closed"></span>
+      <a>Event Timeline</a>
+    </span> ++
+    <div id="task-assignment-timeline" class="collapsed">
+      {
+        if (MAX_TIMELINE_TASKS < tasks.size) {
+          <strong>
+            This stage has more than the maximum number of tasks that can be shown in the
+            visualization! Only the most recent {MAX_TIMELINE_TASKS} tasks
+            (of {tasks.size} total) are shown.
+          </strong>
+        } else {
+          Seq.empty
+        }
+      }
+      <div class="control-panel">
+        <div id="task-assignment-timeline-zoom-lock">
+          <input type="checkbox"></input>
+          <span>Enable zooming</span>
+        </div>
+      </div>
+      {TIMELINE_LEGEND}
+    </div> ++
+    <script type="text/javascript">
+      {Unparsed(s"drawTaskAssignmentTimeline(" +
+      s"$groupArrayStr, $executorsArrayStr, $minLaunchTime, $maxZoom)")}
+    </script>
+  }
+
   def taskRow(
       hasAccumulators: Boolean,
       hasInput: Boolean,
       hasOutput: Boolean,
       hasShuffleRead: Boolean,
       hasShuffleWrite: Boolean,
-      hasBytesSpilled: Boolean)(taskData: TaskUIData): Seq[Node] = {
+      hasBytesSpilled: Boolean,
+      currentTime: Long)(taskData: TaskUIData): Seq[Node] = {
     taskData match { case TaskUIData(info, metrics, errorMessage) =>
-      val duration = if (info.status == "RUNNING") info.timeRunning(System.currentTimeMillis())
+      val duration = if (info.status == "RUNNING") info.timeRunning(currentTime)
         else metrics.map(_.executorRunTime).getOrElse(1L)
       val formatDuration = if (info.status == "RUNNING") UIUtils.formatDuration(duration)
         else metrics.map(m => UIUtils.formatDuration(m.executorRunTime)).getOrElse("")
@@ -542,7 +748,7 @@ private[ui] class StagePage(parent: StagesTab) extends WebUIPage("stage") {
       val diskBytesSpilledSortable = maybeDiskBytesSpilled.map(_.toString).getOrElse("")
       val diskBytesSpilledReadable = maybeDiskBytesSpilled.map(Utils.bytesToString).getOrElse("")
 
-      <tr>
+      <tr id={"task-" + info.index + "-" + info.attempt}>
         <td>{info.index}</td>
         <td>{info.taskId}</td>
         <td sorttable_customkey={info.attempt.toString}>{
diff --git a/core/src/main/scala/org/apache/spark/ui/jobs/StagesTab.scala b/core/src/main/scala/org/apache/spark/ui/jobs/StagesTab.scala
index 55169956d8..5989f0035b 100644
--- a/core/src/main/scala/org/apache/spark/ui/jobs/StagesTab.scala
+++ b/core/src/main/scala/org/apache/spark/ui/jobs/StagesTab.scala
@@ -25,6 +25,7 @@ import org.apache.spark.ui.{SparkUI, SparkUITab}
 /** Web UI showing progress status of all stages in the given SparkContext. */
 private[ui] class StagesTab(parent: SparkUI) extends SparkUITab(parent, "stages") {
   val sc = parent.sc
+  val conf = parent.conf
   val killEnabled = parent.killEnabled
   val progressListener = parent.jobProgressListener
   val operationGraphListener = parent.operationGraphListener