From d2c603bf5e008d6abbf9c7978c14511ae008c1b9 Mon Sep 17 00:00:00 2001
From: skakker <skakker@linkedin.com>
Date: Fri, 28 Jul 2017 19:04:10 +0530
Subject: [PATCH] added logic for map reduce time-skew heuristic (#267)

---
 app-conf/HeuristicConf.xml                    | 12 +--
 app-conf/elephant.conf                        |  2 +-
 .../mapreduce/data/MapReduceTaskData.java     |  7 ++
 ...uristic.java => GenericSkewHeuristic.java} | 98 ++++++++++++++-----
 ...euristic.java => MapperSkewHeuristic.java} |  4 +-
 ...uristic.java => ReducerSkewHeuristic.java} |  4 +-
 ...w.scala.html => helpMapperSkew.scala.html} |  2 +-
 ....scala.html => helpReducerSkew.scala.html} |  4 +-
 .../drelephant/analysis/AnalyticJobTest.java  | 34 +++----
 .../heuristic/HeuristicConfigurationTest.java |  4 +-
 ...Test.java => MapperSkewHeuristicTest.java} | 50 +++++++++-
 ...est.java => ReducerSkewHeuristicTest.java} | 50 +++++++++-
 .../heuristic/HeuristicConfTest1.xml          |  6 +-
 .../heuristic/HeuristicConfTest2.xml          |  4 +-
 .../heuristic/HeuristicConfTest3.xml          |  4 +-
 .../heuristic/HeuristicConfTest4.xml          |  4 +-
 .../heuristic/HeuristicConfTest5.xml          |  4 +-
 test/resources/test-init.sql                  |  2 +-
 test/rest/RestAPITest.java                    |  9 +-
 .../components/heuristic-details-list-test.js |  2 +-
 .../components/heuristics-summary-test.js     |  2 +-
 .../single-heuristic-detail-test.js           |  2 +-
 22 files changed, 230 insertions(+), 80 deletions(-)
 rename app/com/linkedin/drelephant/mapreduce/heuristics/{GenericDataSkewHeuristic.java => GenericSkewHeuristic.java} (55%)
 rename app/com/linkedin/drelephant/mapreduce/heuristics/{MapperDataSkewHeuristic.java => MapperSkewHeuristic.java} (90%)
 rename app/com/linkedin/drelephant/mapreduce/heuristics/{ReducerDataSkewHeuristic.java => ReducerSkewHeuristic.java} (89%)
 rename app/views/help/mapreduce/{helpMapperDataSkew.scala.html => helpMapperSkew.scala.html} (94%)
 rename app/views/help/mapreduce/{helpReducerDataSkew.scala.html => helpReducerSkew.scala.html} (91%)
 rename test/com/linkedin/drelephant/mapreduce/heuristics/{MapperDataSkewHeuristicTest.java => MapperSkewHeuristicTest.java} (65%)
 rename test/com/linkedin/drelephant/mapreduce/heuristics/{ReducerDataSkewHeuristicTest.java => ReducerSkewHeuristicTest.java} (65%)

diff --git a/app-conf/HeuristicConf.xml b/app-conf/HeuristicConf.xml
index 21a00168a..833fa2bc3 100644
--- a/app-conf/HeuristicConf.xml
+++ b/app-conf/HeuristicConf.xml
@@ -21,9 +21,9 @@
 
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
-    <heuristicname>Mapper Data Skew</heuristicname>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</classname>
-    <viewname>views.html.help.mapreduce.helpMapperDataSkew</viewname>
+    <heuristicname>Mapper Skew</heuristicname>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</classname>
+    <viewname>views.html.help.mapreduce.helpMapperSkew</viewname>
     <!--<params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
@@ -93,9 +93,9 @@
 
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
-    <heuristicname>Reducer Data Skew</heuristicname>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.ReducerDataSkewHeuristic</classname>
-    <viewname>views.html.help.mapreduce.helpReducerDataSkew</viewname>
+    <heuristicname>Reducer Skew</heuristicname>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.ReducerSkewHeuristic</classname>
+    <viewname>views.html.help.mapreduce.helpReducerSkew</viewname>
     <!--<params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/app-conf/elephant.conf b/app-conf/elephant.conf
index 2ab7852c2..e784937fa 100644
--- a/app-conf/elephant.conf
+++ b/app-conf/elephant.conf
@@ -27,7 +27,7 @@ enable_analytics=false
 
 # Additional Configuration
 # Check https://www.playframework.com/documentation/2.2.x/ProductionConfiguration
-jvm_args="-Devolutionplugin=enabled -DapplyEvolutions.default=true"
+jvm_props="-Devolutionplugin=enabled -DapplyEvolutions.default=true"
 
 # Property enables dropwizard metrics for the application.
 # More info on Dropwizard metrics at http://metrics.dropwizard.io
diff --git a/app/com/linkedin/drelephant/mapreduce/data/MapReduceTaskData.java b/app/com/linkedin/drelephant/mapreduce/data/MapReduceTaskData.java
index 56696aca1..26f206043 100644
--- a/app/com/linkedin/drelephant/mapreduce/data/MapReduceTaskData.java
+++ b/app/com/linkedin/drelephant/mapreduce/data/MapReduceTaskData.java
@@ -27,11 +27,18 @@ public class MapReduceTaskData {
   private String _taskId;
   // The successful attempt id
   private String _attemptId;
+
+  public void setTotalTimeMs(long totalTimeMs, boolean isTimeDataPresent) {
+    this._totalTimeMs = totalTimeMs;
+    this._isTimeDataPresent = isTimeDataPresent;
+  }
+
   private long _totalTimeMs = 0;
   private long _shuffleTimeMs = 0;
   private long _sortTimeMs = 0;
   private long _startTimeMs = 0;
   private long _finishTimeMs = 0;
+
   // This flag will only be true when successfully setting time and counter values.
   private boolean _isTimeDataPresent = false;
   private boolean _isCounterDataPresent = false;
diff --git a/app/com/linkedin/drelephant/mapreduce/heuristics/GenericDataSkewHeuristic.java b/app/com/linkedin/drelephant/mapreduce/heuristics/GenericSkewHeuristic.java
similarity index 55%
rename from app/com/linkedin/drelephant/mapreduce/heuristics/GenericDataSkewHeuristic.java
rename to app/com/linkedin/drelephant/mapreduce/heuristics/GenericSkewHeuristic.java
index e975760ef..941547db9 100644
--- a/app/com/linkedin/drelephant/mapreduce/heuristics/GenericDataSkewHeuristic.java
+++ b/app/com/linkedin/drelephant/mapreduce/heuristics/GenericSkewHeuristic.java
@@ -28,20 +28,23 @@
 
 import com.linkedin.drelephant.configurations.heuristic.HeuristicConfigurationData;
 import com.linkedin.drelephant.util.Utils;
+
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Map;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.lang.time.DurationFormatUtils;
 import org.apache.log4j.Logger;
 
 
 /**
  * This Heuristic analyses the skewness in the task input data
  */
-public abstract class GenericDataSkewHeuristic implements Heuristic<MapReduceApplicationData> {
-  private static final Logger logger = Logger.getLogger(GenericDataSkewHeuristic.class);
+public abstract class GenericSkewHeuristic implements Heuristic<MapReduceApplicationData> {
+  private static final Logger logger = Logger.getLogger(GenericSkewHeuristic.class);
 
   // Severity Parameters
   private static final String NUM_TASKS_SEVERITY = "num_tasks_severity";
@@ -51,7 +54,7 @@ public abstract class GenericDataSkewHeuristic implements Heuristic<MapReduceApp
   // Default value of parameters
   private double[] numTasksLimits = {10, 50, 100, 200};   // Number of map or reduce tasks
   private double[] deviationLimits = {2, 4, 8, 16};       // Deviation in i/p bytes btw 2 groups
-  private double[] filesLimits = {1d/8, 1d/4, 1d/2, 1d};  // Fraction of HDFS Block Size
+  private double[] filesLimits = {1d / 8, 1d / 4, 1d / 2, 1d};  // Fraction of HDFS Block Size
 
   private List<MapReduceCounterData.CounterName> _counterNames;
   private HeuristicConfigurationData _heuristicConfData;
@@ -78,15 +81,16 @@ private void loadParameters() {
     if (confFilesThreshold != null) {
       filesLimits = confFilesThreshold;
     }
-    logger.info(heuristicName + " will use " + FILES_SEVERITY + " with the following threshold settings: "
-        + Arrays.toString(filesLimits));
+    logger.info(
+        heuristicName + " will use " + FILES_SEVERITY + " with the following threshold settings: " + Arrays.toString(
+            filesLimits));
     for (int i = 0; i < filesLimits.length; i++) {
       filesLimits[i] = filesLimits[i] * HDFSContext.HDFS_BLOCK_SIZE;
     }
   }
 
-  protected GenericDataSkewHeuristic(List<MapReduceCounterData.CounterName> counterNames,
-                                     HeuristicConfigurationData heuristicConfData) {
+  protected GenericSkewHeuristic(List<MapReduceCounterData.CounterName> counterNames,
+      HeuristicConfigurationData heuristicConfData) {
     this._counterNames = counterNames;
     this._heuristicConfData = heuristicConfData;
 
@@ -103,19 +107,48 @@ public HeuristicConfigurationData getHeuristicConfData() {
   @Override
   public HeuristicResult apply(MapReduceApplicationData data) {
 
-    if(!data.getSucceeded()) {
+    if (!data.getSucceeded()) {
       return null;
     }
 
     MapReduceTaskData[] tasks = getTasks(data);
 
+    //Gathering data for checking time skew
+    List<Long> timeTaken = new ArrayList<Long>();
+
+    for (int i = 0; i < tasks.length; i++) {
+      if (tasks[i].isTimeDataPresent()) {
+        timeTaken.add(tasks[i].getTotalRunTimeMs());
+      }
+    }
+
+    long[][] groupsTime = Statistics.findTwoGroups(Longs.toArray(timeTaken));
+
+    long timeAvg1 = Statistics.average(groupsTime[0]);
+    long timeAvg2 = Statistics.average(groupsTime[1]);
+
+    //seconds are used for calculating deviation as they provide a better idea than millisecond.
+    long timeAvgSec1 = TimeUnit.MILLISECONDS.toSeconds(timeAvg1);
+    long timeAvgSec2 = TimeUnit.MILLISECONDS.toSeconds(timeAvg2);
+
+    long minTime = Math.min(timeAvgSec1, timeAvgSec2);
+    long diffTime = Math.abs(timeAvgSec1 - timeAvgSec2);
+
+    //using the same deviation limits for time skew as for data skew. It can be changed in the fututre.
+    Severity severityTime = getDeviationSeverity(minTime, diffTime);
+
+    //This reduces severity if number of tasks is insignificant
+    severityTime = Severity.min(severityTime,
+        Severity.getSeverityAscending(groupsTime[0].length, numTasksLimits[0], numTasksLimits[1], numTasksLimits[2],
+            numTasksLimits[3]));
+
     //Gather data
     List<Long> inputBytes = new ArrayList<Long>();
 
     for (int i = 0; i < tasks.length; i++) {
       if (tasks[i].isCounterDataPresent()) {
         long inputByte = 0;
-        for (MapReduceCounterData.CounterName counterName: _counterNames) {
+        for (MapReduceCounterData.CounterName counterName : _counterNames) {
           inputByte += tasks[i].getCounters().get(counterName);
         }
         inputBytes.add(inputByte);
@@ -123,7 +156,7 @@ public HeuristicResult apply(MapReduceApplicationData data) {
     }
 
     // Ratio of total tasks / sampled tasks
-    double scale = ((double)tasks.length) / inputBytes.size();
+    double scale = ((double) tasks.length) / inputBytes.size();
     //Analyze data. TODO: This is a temp fix. findTwogroups should support list as input
     long[][] groups = Statistics.findTwoGroups(Longs.toArray(inputBytes));
 
@@ -133,37 +166,54 @@ public HeuristicResult apply(MapReduceApplicationData data) {
     long min = Math.min(avg1, avg2);
     long diff = Math.abs(avg2 - avg1);
 
-    Severity severity = getDeviationSeverity(min, diff);
+    Severity severityData = getDeviationSeverity(min, diff);
 
     //This reduces severity if the largest file sizes are insignificant
-    severity = Severity.min(severity, getFilesSeverity(avg2));
+    severityData = Severity.min(severityData, getFilesSeverity(avg2));
 
     //This reduces severity if number of tasks is insignificant
-    severity = Severity.min(severity, Severity.getSeverityAscending(
-        groups[0].length, numTasksLimits[0], numTasksLimits[1], numTasksLimits[2], numTasksLimits[3]));
+    severityData = Severity.min(severityData,
+        Severity.getSeverityAscending(groups[0].length, numTasksLimits[0], numTasksLimits[1], numTasksLimits[2],
+            numTasksLimits[3]));
+
+    Severity severity = Severity.max(severityData, severityTime);
+
+    HeuristicResult result =
+        new HeuristicResult(_heuristicConfData.getClassName(), _heuristicConfData.getHeuristicName(), severity,
+            Utils.getHeuristicScore(severityData, tasks.length));
 
-    HeuristicResult result = new HeuristicResult(_heuristicConfData.getClassName(),
-        _heuristicConfData.getHeuristicName(), severity, Utils.getHeuristicScore(severity, tasks.length));
+    result.addResultDetail("Data skew (Number of tasks)", Integer.toString(tasks.length));
+    result.addResultDetail("Data skew (Group A)",
+        groups[0].length + " tasks @ " + FileUtils.byteCountToDisplaySize(avg1) + " avg");
+    result.addResultDetail("Data skew (Group B)",
+        groups[1].length + " tasks @ " + FileUtils.byteCountToDisplaySize(avg2) + " avg");
 
-    result.addResultDetail("Number of tasks", Integer.toString(tasks.length));
-    result.addResultDetail("Group A", groups[0].length + " tasks @ " + FileUtils.byteCountToDisplaySize(avg1) + " avg");
-    result.addResultDetail("Group B", groups[1].length + " tasks @ " + FileUtils.byteCountToDisplaySize(avg2) + " avg");
+    result.addResultDetail("Time skew (Number of tasks)", Integer.toString(tasks.length));
+    result.addResultDetail("Time skew (Group A)",
+        groupsTime[0].length + " tasks @ " + convertTimeMs(timeAvg1) + " avg");
+    result.addResultDetail("Time skew (Group B)",
+        groupsTime[1].length + " tasks @ " + convertTimeMs(timeAvg2) + " avg");
 
     return result;
   }
 
+  private String convertTimeMs(long timeMs) {
+    if (timeMs < 1000) {
+      return Long.toString(timeMs) + " msec";
+    }
+    return DurationFormatUtils.formatDuration(timeMs, "HH:mm:ss") + " HH:MM:SS";
+  }
+
   private Severity getDeviationSeverity(long averageMin, long averageDiff) {
     if (averageMin <= 0) {
       averageMin = 1;
     }
     long value = averageDiff / averageMin;
-    return Severity.getSeverityAscending(
-        value, deviationLimits[0], deviationLimits[1], deviationLimits[2], deviationLimits[3]);
+    return Severity.getSeverityAscending(value, deviationLimits[0], deviationLimits[1], deviationLimits[2],
+        deviationLimits[3]);
   }
 
   private Severity getFilesSeverity(long value) {
-    return Severity.getSeverityAscending(
-        value, filesLimits[0], filesLimits[1], filesLimits[2], filesLimits[3]);
+    return Severity.getSeverityAscending(value, filesLimits[0], filesLimits[1], filesLimits[2], filesLimits[3]);
   }
-
 }
diff --git a/app/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristic.java b/app/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristic.java
similarity index 90%
rename from app/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristic.java
rename to app/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristic.java
index 6709e0b46..7a7075051 100644
--- a/app/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristic.java
+++ b/app/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristic.java
@@ -27,9 +27,9 @@
 /**
  * This Heuristic analyses the skewness in the mapper input data
  */
-public class MapperDataSkewHeuristic extends GenericDataSkewHeuristic {
+public class MapperSkewHeuristic extends GenericSkewHeuristic {
 
-  public MapperDataSkewHeuristic(HeuristicConfigurationData heuristicConfData) {
+  public MapperSkewHeuristic(HeuristicConfigurationData heuristicConfData) {
     super(Arrays.asList(
         MapReduceCounterData.CounterName.HDFS_BYTES_READ,
         MapReduceCounterData.CounterName.S3_BYTES_READ,
diff --git a/app/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristic.java b/app/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristic.java
similarity index 89%
rename from app/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristic.java
rename to app/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristic.java
index c01547623..d5b310b0d 100644
--- a/app/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristic.java
+++ b/app/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristic.java
@@ -28,9 +28,9 @@
 /**
  * This Heuristic analyses the skewness in the reducer input data
  */
-public class ReducerDataSkewHeuristic extends GenericDataSkewHeuristic {
+public class ReducerSkewHeuristic extends GenericSkewHeuristic {
 
-  public ReducerDataSkewHeuristic(HeuristicConfigurationData heuristicConfData) {
+  public ReducerSkewHeuristic(HeuristicConfigurationData heuristicConfData) {
     super(Arrays.asList(MapReduceCounterData.CounterName.REDUCE_SHUFFLE_BYTES), heuristicConfData);
   }
 
diff --git a/app/views/help/mapreduce/helpMapperDataSkew.scala.html b/app/views/help/mapreduce/helpMapperSkew.scala.html
similarity index 94%
rename from app/views/help/mapreduce/helpMapperDataSkew.scala.html
rename to app/views/help/mapreduce/helpMapperSkew.scala.html
index 50aa9312d..d897d982a 100644
--- a/app/views/help/mapreduce/helpMapperDataSkew.scala.html
+++ b/app/views/help/mapreduce/helpMapperSkew.scala.html
@@ -15,7 +15,7 @@
 *@
 
 <p>
-    This analysis shows whether there is a data-skew for the data entering mapper tasks.
+    This analysis shows whether there is a data/time-skew for the data/time entering mapper tasks.
 </p>
 <p>
     This result of the analysis shows two groups of the spectrum, where the first group has significantly less input data compared to the second group.
diff --git a/app/views/help/mapreduce/helpReducerDataSkew.scala.html b/app/views/help/mapreduce/helpReducerSkew.scala.html
similarity index 91%
rename from app/views/help/mapreduce/helpReducerDataSkew.scala.html
rename to app/views/help/mapreduce/helpReducerSkew.scala.html
index d0213d9d6..4a842cb67 100644
--- a/app/views/help/mapreduce/helpReducerDataSkew.scala.html
+++ b/app/views/help/mapreduce/helpReducerSkew.scala.html
@@ -15,7 +15,7 @@
 *@
 
 <p>
-    This analysis shows whether there is a data-skew for the data entering reducer tasks.
+    This analysis shows whether there is a data/time-skew for the data/time entering reducer tasks.
 </p>
 <p>
     This result of the analysis shows two groups of the spectrum, where the first group has significantly less input data compared to the second group.
@@ -24,7 +24,7 @@ <h5>Example</h5>
 <p>
 <div class="list-group">
     <a class="list-group-item list-group-item-danger" href="">
-        <h4 class="list-group-item-heading">Reducer Data Skew</h4>
+        <h4 class="list-group-item-heading">Reducer Skew</h4>
         <table class="list-group-item-text table table-condensed left-table">
             <thead><tr><th colspan="2">Severity: Critical</th></tr></thead>
             <tbody>
diff --git a/test/com/linkedin/drelephant/analysis/AnalyticJobTest.java b/test/com/linkedin/drelephant/analysis/AnalyticJobTest.java
index 6d71e2d26..06b5dae36 100644
--- a/test/com/linkedin/drelephant/analysis/AnalyticJobTest.java
+++ b/test/com/linkedin/drelephant/analysis/AnalyticJobTest.java
@@ -22,7 +22,7 @@
 import com.linkedin.drelephant.mapreduce.data.MapReduceApplicationData;
 import com.linkedin.drelephant.mapreduce.data.MapReduceCounterData;
 import com.linkedin.drelephant.mapreduce.data.MapReduceTaskData;
-import com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic;
+import com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic;
 import common.TestUtil;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -160,40 +160,40 @@ private List<Heuristic> loadHeuristics() {
     List<Heuristic> heuristics = new ArrayList<Heuristic>();
     // dummy hash map
     Map<String, String> paramsMap = new HashMap<String, String>();
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Mapper Data Skew",
-        "com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic",
-        "views.html.help.mapreduce.helpMapperDataSkew", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Mapper Skew",
+        "com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic",
+        "views.html.help.mapreduce.helpMapperSkew", new ApplicationType("mapreduce"), paramsMap)));
+    heuristics.add(new MapperSkewHeuristic(
         new HeuristicConfigurationData("Mapper GC", "com.linkedin.drelephant.mapreduce.heuristics.MapperGCHeuristic",
             "views.html.help.mapreduce.helpGC", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Mapper Time",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Mapper Time",
         "com.linkedin.drelephant.mapreduce.heuristics.MapperTimeHeuristic", "views.html.help.mapreduce.helpMapperTime",
         new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Mapper Speed",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Mapper Speed",
         "com.linkedin.drelephant.mapreduce.heuristics.MapperSpeedHeuristic",
         "views.html.help.mapreduce.helpMapperSpeed", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Mapper Spill",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Mapper Spill",
         "com.linkedin.drelephant.mapreduce.heuristics.MapperSpillHeuristic",
         "views.html.help.mapreduce.helpMapperSpill", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Mapper Memory",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Mapper Memory",
         "com.linkedin.drelephant.mapreduce.heuristics.MapperMemoryHeuristic",
         "views.html.help.mapreduce.helpMapperMemory", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Reducer Data Skew",
-        "com.linkedin.drelephant.mapreduce.heuristics.ReducerDataSkewHeuristic",
-        "views.html.help.mapreduce.helpReducerDataSkew", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Reducer Skew",
+        "com.linkedin.drelephant.mapreduce.heuristics.ReducerSkewHeuristic",
+        "views.html.help.mapreduce.helpReducerSkew", new ApplicationType("mapreduce"), paramsMap)));
+    heuristics.add(new MapperSkewHeuristic(
         new HeuristicConfigurationData("Reducer GC", "com.linkedin.drelephant.mapreduce.heuristics.ReducerGCHeuristic",
             "views.html.help.mapreduce.helpGC", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Reducer Time",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Reducer Time",
         "com.linkedin.drelephant.mapreduce.heuristics.ReducerTimeHeuristic",
         "views.html.help.mapreduce.helpReducerTime", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Reducer Memory",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Reducer Memory",
         "com.linkedin.drelephant.mapreduce.heuristics.ReducerMemoryHeuristic",
         "views.html.help.mapreduce.helpReducerMemory", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(new HeuristicConfigurationData("Shuffle &#38; Sort",
+    heuristics.add(new MapperSkewHeuristic(new HeuristicConfigurationData("Shuffle &#38; Sort",
         "com.linkedin.drelephant.mapreduce.heuristics.ShuffleSortHeuristic",
         "views.html.help.mapreduce.helpShuffleSort", new ApplicationType("mapreduce"), paramsMap)));
-    heuristics.add(new MapperDataSkewHeuristic(
+    heuristics.add(new MapperSkewHeuristic(
         new HeuristicConfigurationData("Exception", "com.linkedin.drelephant.mapreduce.heuristics.ExceptionHeuristic",
             "views.html.help.mapreduce.helpException", new ApplicationType("mapreduce"), paramsMap)));
 
diff --git a/test/com/linkedin/drelephant/configurations/heuristic/HeuristicConfigurationTest.java b/test/com/linkedin/drelephant/configurations/heuristic/HeuristicConfigurationTest.java
index 8eaf34aad..16c3c8a6f 100644
--- a/test/com/linkedin/drelephant/configurations/heuristic/HeuristicConfigurationTest.java
+++ b/test/com/linkedin/drelephant/configurations/heuristic/HeuristicConfigurationTest.java
@@ -95,7 +95,7 @@ public void testParseFetcherConf2() {
   public void testParseFetcherConf3() {
     expectedEx.expect(RuntimeException.class);
     expectedEx.expectMessage("No tag 'heuristicname' in heuristic 1 classname"
-        + " com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic");
+        + " com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic");
     HeuristicConfiguration heuristicConf = new HeuristicConfiguration(document3.getDocumentElement());
   }
 
@@ -106,7 +106,7 @@ public void testParseFetcherConf3() {
   public void testParseFetcherConf4() {
     expectedEx.expect(RuntimeException.class);
     expectedEx.expectMessage("No tag 'viewname' in heuristic 1 classname"
-        + " com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic");
+        + " com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic");
     HeuristicConfiguration heuristicConf = new HeuristicConfiguration(document4.getDocumentElement());
   }
 
diff --git a/test/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristicTest.java b/test/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristicTest.java
similarity index 65%
rename from test/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristicTest.java
rename to test/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristicTest.java
index 99557466d..3a26d31c6 100644
--- a/test/com/linkedin/drelephant/mapreduce/heuristics/MapperDataSkewHeuristicTest.java
+++ b/test/com/linkedin/drelephant/mapreduce/heuristics/MapperSkewHeuristicTest.java
@@ -33,12 +33,13 @@
 import junit.framework.TestCase;
 
 
-public class MapperDataSkewHeuristicTest extends TestCase {
+public class MapperSkewHeuristicTest extends TestCase {
 
   private static final long UNITSIZE = HDFSContext.HDFS_BLOCK_SIZE / 64; //1MB
+  private static final long UNITSIZETIME = 1000000; //1000sec
 
   private static Map<String, String> paramsMap = new HashMap<String, String>();
-  private static Heuristic _heuristic = new MapperDataSkewHeuristic(new HeuristicConfigurationData("test_heuristic",
+  private static Heuristic _heuristic = new MapperSkewHeuristic(new HeuristicConfigurationData("test_heuristic",
       "test_class", "test_view", new ApplicationType("test_apptype"), paramsMap));
 
   public void testCritical() throws IOException {
@@ -69,6 +70,30 @@ public void testSmallTasks() throws IOException {
     assertEquals(Severity.NONE, analyzeJob(5, 5, 10 * UNITSIZE, 100 * UNITSIZE));
   }
 
+  public void testCriticalTime() throws IOException {
+    assertEquals(Severity.CRITICAL, analyzeJobTime(200, 200, 1 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testSevereTime() throws IOException {
+    assertEquals(Severity.SEVERE, analyzeJobTime(200, 200, 10 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testModerateTime() throws IOException {
+    assertEquals(Severity.MODERATE, analyzeJobTime(200, 200, 20 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testLowTime() throws IOException {
+    assertEquals(Severity.LOW, analyzeJobTime(200, 200, 30 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testNoneTime() throws IOException {
+    assertEquals(Severity.NONE, analyzeJobTime(200, 200, 50 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testSmallTasksTime() throws IOException {
+    assertEquals(Severity.NONE, analyzeJobTime(5, 5, 10 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
   private Severity analyzeJob(int numSmallTasks, int numLargeTasks, long smallInputSize, long largeInputSize)
       throws IOException {
     MapReduceCounterData jobCounter = new MapReduceCounterData();
@@ -97,4 +122,25 @@ private Severity analyzeJob(int numSmallTasks, int numLargeTasks, long smallInpu
     return result.getSeverity();
 
   }
+
+  private Severity analyzeJobTime(int numSmallTasks, int numLongTasks, long smallTimeTaken, long longTimeTaken)
+          throws IOException {
+    MapReduceTaskData[] mappers = new MapReduceTaskData[numSmallTasks + numLongTasks + 1];
+
+    int i = 0;
+    for (; i < numSmallTasks; i++) {
+      mappers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+      mappers[i].setTotalTimeMs(smallTimeTaken, true);
+    }
+    for (; i < numSmallTasks + numLongTasks; i++) {
+      mappers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+      mappers[i].setTotalTimeMs(longTimeTaken, true);
+    }
+    // Non-sampled task, which does not contain time data
+    mappers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+    MapReduceApplicationData data = new MapReduceApplicationData().setMapperData(mappers);
+    HeuristicResult result = _heuristic.apply(data);
+    return result.getSeverity();
+
+  }
 }
diff --git a/test/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristicTest.java b/test/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristicTest.java
similarity index 65%
rename from test/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristicTest.java
rename to test/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristicTest.java
index 5ceaa8049..450e0becb 100644
--- a/test/com/linkedin/drelephant/mapreduce/heuristics/ReducerDataSkewHeuristicTest.java
+++ b/test/com/linkedin/drelephant/mapreduce/heuristics/ReducerSkewHeuristicTest.java
@@ -33,11 +33,12 @@
 import junit.framework.TestCase;
 
 
-public class ReducerDataSkewHeuristicTest extends TestCase {
+public class ReducerSkewHeuristicTest extends TestCase {
   private static final long UNITSIZE = HDFSContext.HDFS_BLOCK_SIZE / 64; //1mb
+  private static final long UNITSIZETIME = 1000000; //1000sec
 
   private static Map<String, String> paramsMap = new HashMap<String, String>();
-  private static Heuristic _heuristic = new ReducerDataSkewHeuristic(new HeuristicConfigurationData("test_heuristic",
+  private static Heuristic _heuristic = new ReducerSkewHeuristic(new HeuristicConfigurationData("test_heuristic",
       "test_class", "test_view", new ApplicationType("test_apptype"), paramsMap));
 
   public void testCritical() throws IOException {
@@ -68,6 +69,30 @@ public void testSmallTasks() throws IOException {
     assertEquals(Severity.NONE, analyzeJob(5, 5, 10 * UNITSIZE, 100 * UNITSIZE));
   }
 
+  public void testCriticalTime() throws IOException {
+    assertEquals(Severity.CRITICAL, analyzeJobTime(200, 200, 1 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testSevereTime() throws IOException {
+    assertEquals(Severity.SEVERE, analyzeJobTime(200, 200, 10 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testModerateTime() throws IOException {
+    assertEquals(Severity.MODERATE, analyzeJobTime(200, 200, 20 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testLowTime() throws IOException {
+    assertEquals(Severity.LOW, analyzeJobTime(200, 200, 30 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testNoneTime() throws IOException {
+    assertEquals(Severity.NONE, analyzeJobTime(200, 200, 50 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
+  public void testSmallTasksTime() throws IOException {
+    assertEquals(Severity.NONE, analyzeJobTime(5, 5, 10 * UNITSIZETIME, 100 * UNITSIZETIME));
+  }
+
   private Severity analyzeJob(int numSmallTasks, int numLargeTasks, long smallInputSize, long largeInputSize)
       throws IOException {
     MapReduceCounterData jobCounter = new MapReduceCounterData();
@@ -95,4 +120,25 @@ private Severity analyzeJob(int numSmallTasks, int numLargeTasks, long smallInpu
     HeuristicResult result = _heuristic.apply(data);
     return result.getSeverity();
   }
+
+  private Severity analyzeJobTime(int numSmallTasks, int numLongTasks, long smallTimeTaken, long longTimeTaken)
+          throws IOException {
+    MapReduceTaskData[] reducers = new MapReduceTaskData[numSmallTasks + numLongTasks + 1];
+
+    int i = 0;
+    for (; i < numSmallTasks; i++) {
+      reducers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+      reducers[i].setTotalTimeMs(smallTimeTaken, true);
+    }
+    for (; i < numSmallTasks + numLongTasks; i++) {
+      reducers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+      reducers[i].setTotalTimeMs(longTimeTaken, true);
+    }
+    // Non-sampled task, which does not contain time data
+    reducers[i] = new MapReduceTaskData("task-id-"+i, "task-attempt-id-"+i);
+    MapReduceApplicationData data = new MapReduceApplicationData().setReducerData(reducers);
+    HeuristicResult result = _heuristic.apply(data);
+    return result.getSeverity();
+
+  }
 }
diff --git a/test/resources/configurations/heuristic/HeuristicConfTest1.xml b/test/resources/configurations/heuristic/HeuristicConfTest1.xml
index 47f4e94f6..540b81b00 100644
--- a/test/resources/configurations/heuristic/HeuristicConfTest1.xml
+++ b/test/resources/configurations/heuristic/HeuristicConfTest1.xml
@@ -21,9 +21,9 @@
 
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
-    <heuristicname>Mapper Data Skew</heuristicname>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</classname>
-    <viewname>views.html.help.mapreduce.helpMapperDataSkew</viewname>
+    <heuristicname>Mapper Skew</heuristicname>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</classname>
+    <viewname>views.html.help.mapreduce.helpMapperSkew</viewname>
     <params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/test/resources/configurations/heuristic/HeuristicConfTest2.xml b/test/resources/configurations/heuristic/HeuristicConfTest2.xml
index acb1822bd..dd755d696 100644
--- a/test/resources/configurations/heuristic/HeuristicConfTest2.xml
+++ b/test/resources/configurations/heuristic/HeuristicConfTest2.xml
@@ -22,8 +22,8 @@
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
     <heuristicname>Mapper Data Skew</heuristicname>
-    <class>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</class>
-    <viewname>views.html.help.mapreduce.helpMapperDataSkew</viewname>
+    <class>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</class>
+    <viewname>views.html.help.mapreduce.helpMapperSkew</viewname>
     <params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/test/resources/configurations/heuristic/HeuristicConfTest3.xml b/test/resources/configurations/heuristic/HeuristicConfTest3.xml
index 2af761905..7f4e5bd72 100644
--- a/test/resources/configurations/heuristic/HeuristicConfTest3.xml
+++ b/test/resources/configurations/heuristic/HeuristicConfTest3.xml
@@ -22,8 +22,8 @@
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
     <heuristic>Mapper Data Skew</heuristic>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</classname>
-    <viewname>views.html.help.mapreduce.helpMapperDataSkew</viewname>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</classname>
+    <viewname>views.html.help.mapreduce.helpMapperSkew</viewname>
     <params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/test/resources/configurations/heuristic/HeuristicConfTest4.xml b/test/resources/configurations/heuristic/HeuristicConfTest4.xml
index 7aae55de1..5686e8b35 100644
--- a/test/resources/configurations/heuristic/HeuristicConfTest4.xml
+++ b/test/resources/configurations/heuristic/HeuristicConfTest4.xml
@@ -22,8 +22,8 @@
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
     <heuristicname>Mapper Data Skew</heuristicname>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</classname>
-    <view>views.html.help.mapreduce.helpMapperDataSkew</view>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</classname>
+    <view>views.html.help.mapreduce.helpMapperSkew</view>
     <params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/test/resources/configurations/heuristic/HeuristicConfTest5.xml b/test/resources/configurations/heuristic/HeuristicConfTest5.xml
index 358a652e0..612aa0834 100644
--- a/test/resources/configurations/heuristic/HeuristicConfTest5.xml
+++ b/test/resources/configurations/heuristic/HeuristicConfTest5.xml
@@ -22,8 +22,8 @@
   <heuristic>
     <applicationtype>mapreduce</applicationtype>
     <heuristicname>Mapper Data Skew</heuristicname>
-    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic</classname>
-    <viewname>views.html.help.mapreduce.helpMapperDataSkew</viewname>
+    <classname>com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic</classname>
+    <viewname>views.html.help.mapreduce.helpMapperSkew</viewname>
     <params>
       <num_tasks_severity>10, 50, 100, 200</num_tasks_severity>
       <deviation_severity>2, 4, 8, 16</deviation_severity>
diff --git a/test/resources/test-init.sql b/test/resources/test-init.sql
index 4cb8a72c1..74901fa8e 100644
--- a/test/resources/test-init.sql
+++ b/test/resources/test-init.sql
@@ -3,6 +3,6 @@ insert into yarn_app_result
     ('application_1458194917883_1453361','Email Overwriter','growth','misc_default',1460980616502,1460980723925,'http://elephant.linkedin.com:19888/jobhistory/job/job_1458194917883_1453361','HadoopJava',0,0,0,'azkaban','overwriter-reminder2','https://elephant.linkedin.com:8443/executor?execid=1654676&job=overwriter-reminder2&attempt=0','https://elephant.linkedin.com:8443/executor?execid=1654676','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder&job=overwriter-reminder2','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder','https://elephant.linkedin.com:8443/executor?execid=1654676&job=overwriter-reminder2&attempt=0','https://elephant.linkedin.com:8443/executor?execid=1654676','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder&job=overwriter-reminder2','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder', 100, 30, 20),
     ('application_1458194917883_1453362','Email Overwriter','metrics','misc_default',1460980823925,1460980923925,'http://elephant.linkedin.com:19888/jobhistory/job/job_1458194917883_1453362','HadoopJava',0,0,0,'azkaban','overwriter-reminder2','https://elephant.linkedin.com:8443/executor?execid=1654677&job=overwriter-reminder2&attempt=0','https://elephant.linkedin.com:8443/executor?execid=1654677','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder&job=overwriter-reminder2','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder','https://elephant.linkedin.com:8443/executor?execid=1654677&job=overwriter-reminder2&attempt=0','https://elephant.linkedin.com:8443/executor?execid=1654677','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder&job=overwriter-reminder2','https://elephant.linkedin.com:8443/manager?project=b2-confirm-email-reminder&flow=reminder', 200, 40, 10);
 
-insert into yarn_app_heuristic_result(id,yarn_app_result_id,heuristic_class,heuristic_name,severity,score) values (137594512,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic','Mapper Data Skew',0,0), (137594513,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperGCHeuristic','Mapper GC',0,0), (137594516,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperTimeHeuristic','Mapper Time',0,0), (137594520,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperSpeedHeuristic','Mapper Speed',0,0), (137594523,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperSpillHeuristic','Mapper Spill',0,0), (137594525,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperMemoryHeuristic','Mapper Memory',0,0), (137594530,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerDataSkewHeuristic','Reducer Data Skew',0,0), (137594531,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerGCHeuristic','Reducer Time',0,0), (137594534,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerTimeHeuristic','Reducer GC',0,0), (137594537,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerMemoryHeuristic','Reducer Memory',0,0), (137594540,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ShuffleSortHeuristic','Shuffle & Sort',0,0), (137594612,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperDataSkewHeuristic','Mapper Data Skew',0,0), (137594613,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperGCHeuristic','Mapper GC',0,0), (137594616,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperTimeHeuristic','Mapper Time',0,0), (137594620,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperSpeedHeuristic','Mapper Speed',0,0), (137594623,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperSpillHeuristic','Mapper Spill',0,0), (137594625,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperMemoryHeuristic','Mapper Memory',0,0), (137594630,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerDataSkewHeuristic','Reducer Data Skew',0,0), (137594631,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerGCHeuristic','Reducer Time',0,0), (137594634,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerTimeHeuristic','Reducer GC',0,0), (137594637,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerMemoryHeuristic','Reducer Memory',0,0), (137594640,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ShuffleSortHeuristic','Shuffle & Sort',0,0);
+insert into yarn_app_heuristic_result(id,yarn_app_result_id,heuristic_class,heuristic_name,severity,score) values (137594512,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic','Mapper Skew',0,0), (137594513,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperGCHeuristic','Mapper GC',0,0), (137594516,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperTimeHeuristic','Mapper Time',0,0), (137594520,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperSpeedHeuristic','Mapper Speed',0,0), (137594523,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperSpillHeuristic','Mapper Spill',0,0), (137594525,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.MapperMemoryHeuristic','Mapper Memory',0,0), (137594530,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerSkewHeuristic','Reducer Skew',0,0), (137594531,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerGCHeuristic','Reducer Time',0,0), (137594534,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerTimeHeuristic','Reducer GC',0,0), (137594537,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ReducerMemoryHeuristic','Reducer Memory',0,0), (137594540,'application_1458194917883_1453361','com.linkedin.drelephant.mapreduce.heuristics.ShuffleSortHeuristic','Shuffle & Sort',0,0), (137594612,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperSkewHeuristic','Mapper Skew',0,0), (137594613,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperGCHeuristic','Mapper GC',0,0), (137594616,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperTimeHeuristic','Mapper Time',0,0), (137594620,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperSpeedHeuristic','Mapper Speed',0,0), (137594623,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperSpillHeuristic','Mapper Spill',0,0), (137594625,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.MapperMemoryHeuristic','Mapper Memory',0,0), (137594630,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerSkewHeuristic','Reducer Skew',0,0), (137594631,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerGCHeuristic','Reducer Time',0,0), (137594634,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerTimeHeuristic','Reducer GC',0,0), (137594637,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ReducerMemoryHeuristic','Reducer Memory',0,0), (137594640,'application_1458194917883_1453362','com.linkedin.drelephant.mapreduce.heuristics.ShuffleSortHeuristic','Shuffle & Sort',0,0);
 
 insert into yarn_app_heuristic_result_details (yarn_app_heuristic_result_id,name,value,details) values (137594512,'Group A','1 tasks @ 4 MB avg','NULL'), (137594512,'Group B','1 tasks @ 79 MB avg','NULL'), (137594512,'Number of tasks','2','NULL'), (137594513,'Avg task CPU time (ms)','11510','NULL'), (137594513,'Avg task GC time (ms)','76','NULL'), (137594513,'Avg task runtime (ms)','11851','NULL'), (137594513,'Number of tasks','2','NULL'), (137594513,'Task GC/CPU ratio','0.006602953953084275 ','NULL'), (137594516,'Average task input size','42 MB','NULL'), (137594516,'Average task runtime','11 sec','NULL'), (137594516,'Max task runtime','12 sec','NULL'), (137594516,'Min task runtime','11 sec','NULL'), (137594516,'Number of tasks','2','NULL'), (137594520,'Median task input size','42 MB','NULL'), (137594520,'Median task runtime','11 sec','NULL'), (137594520,'Median task speed','3 MB/s','NULL'), (137594520,'Number of tasks','2','NULL'), (137594523,'Avg output records per task','56687','NULL'), (137594523,'Avg spilled records per task','79913','NULL'), (137594523,'Number of tasks','2','NULL'), (137594523,'Ratio of spilled records to output records','1.4097111356119074','NULL'), (137594525,'Avg Physical Memory (MB)','522','NULL'), (137594525,'Avg task runtime','11 sec','NULL'), (137594525,'Avg Virtual Memory (MB)','3307','NULL'), (137594525,'Max Physical Memory (MB)','595','NULL'), (137594525,'Min Physical Memory (MB)','449','NULL'), (137594525,'Number of tasks','2','NULL'), (137594525,'Requested Container Memory','2 GB','NULL'), (137594530,'Group A','11 tasks @ 868 KB avg','NULL'), (137594530,'Group B','9 tasks @ 883 KB avg ','NULL'), (137594530,'Number of tasks','20','NULL'), (137594531,'Avg task CPU time (ms)','8912','NULL'), (137594531,'Avg task GC time (ms)','73','NULL'), (137594531,'Avg task runtime (ms)','11045','NULL'), (137594531,'Number of tasks','20','NULL'), (137594531,'Task GC/CPU ratio','0.008191202872531419 ','NULL'), (137594534,'Average task runtime','11 sec','NULL'), (137594534,'Max task runtime','14 sec','NULL'), (137594534,'Min task runtime','8 sec','NULL'), (137594534,'Number of tasks','20','NULL'), (137594537,'Avg Physical Memory (MB)','416','NULL'), (137594537,'Avg task runtime','11 sec','NULL'), (137594537,'Avg Virtual Memory (MB)','3326','NULL'), (137594537,'Max Physical Memory (MB)','497','NULL'), (137594537,'Min Physical Memory (MB)','354','NULL'), (137594537,'Number of tasks','20','NULL'), (137594537,'Requested Container Memory','2 GB','NULL'), (137594540,'Average code runtime','1 sec','NULL'), (137594540,'Average shuffle time','9 sec (5.49x)','NULL'), (137594540,'Average sort time','(0.04x)','NULL'), (137594540,'Number of tasks','20','NULL'), (137594612,'Group A','1 tasks @ 4 MB avg','NULL'), (137594612,'Group B','1 tasks @ 79 MB avg','NULL'), (137594612,'Number of tasks','2','NULL'), (137594613,'Avg task CPU time (ms)','11510','NULL'), (137594613,'Avg task GC time (ms)','76','NULL'), (137594613,'Avg task runtime (ms)','11851','NULL'), (137594613,'Number of tasks','2','NULL'), (137594613,'Task GC/CPU ratio','0.006602953953084275 ','NULL'), (137594616,'Average task input size','42 MB','NULL'), (137594616,'Average task runtime','11 sec','NULL'), (137594616,'Max task runtime','12 sec','NULL'), (137594616,'Min task runtime','11 sec','NULL'), (137594616,'Number of tasks','2','NULL'), (137594620,'Median task input size','42 MB','NULL'), (137594620,'Median task runtime','11 sec','NULL'), (137594620,'Median task speed','3 MB/s','NULL'), (137594620,'Number of tasks','2','NULL'), (137594623,'Avg output records per task','56687','NULL'), (137594623,'Avg spilled records per task','79913','NULL'), (137594623,'Number of tasks','2','NULL'), (137594623,'Ratio of spilled records to output records','1.4097111356119074','NULL'), (137594625,'Avg Physical Memory (MB)','522','NULL'), (137594625,'Avg task runtime','11 sec','NULL'), (137594625,'Avg Virtual Memory (MB)','3307','NULL'), (137594625,'Max Physical Memory (MB)','595','NULL'), (137594625,'Min Physical Memory (MB)','449','NULL'), (137594625,'Number of tasks','2','NULL'), (137594625,'Requested Container Memory','2 GB','NULL'), (137594630,'Group A','11 tasks @ 868 KB avg','NULL'), (137594630,'Group B','9 tasks @ 883 KB avg ','NULL'), (137594630,'Number of tasks','20','NULL'), (137594631,'Avg task CPU time (ms)','8912','NULL'), (137594631,'Avg task GC time (ms)','73','NULL'), (137594631,'Avg task runtime (ms)','11045','NULL'), (137594631,'Number of tasks','20','NULL'), (137594631,'Task GC/CPU ratio','0.008191202872531419 ','NULL'), (137594634,'Average task runtime','11 sec','NULL'), (137594634,'Max task runtime','14 sec','NULL'), (137594634,'Min task runtime','8 sec','NULL'), (137594634,'Number of tasks','20','NULL'), (137594637,'Avg Physical Memory (MB)','416','NULL'), (137594637,'Avg task runtime','11 sec','NULL'), (137594637,'Avg Virtual Memory (MB)','3326','NULL'), (137594637,'Max Physical Memory (MB)','497','NULL'), (137594637,'Min Physical Memory (MB)','354','NULL'), (137594637,'Number of tasks','20','NULL'), (137594637,'Requested Container Memory','2 GB','NULL'), (137594640,'Average code runtime','1 sec','NULL'), (137594640,'Average shuffle time','9 sec (5.49x)','NULL'), (137594640,'Average sort time','(0.04x)','NULL'), (137594640,'Number of tasks','20','NULL');
diff --git a/test/rest/RestAPITest.java b/test/rest/RestAPITest.java
index 9e055ee4a..cdfb8ab7d 100644
--- a/test/rest/RestAPITest.java
+++ b/test/rest/RestAPITest.java
@@ -455,6 +455,7 @@ public void run() {
         final WS.Response response = WS.url(BASE_URL + REST_APPLICATION_SUMMARIES_PATH).
             setQueryParameter("username", TEST_USERNAME).
             get().get(RESPONSE_TIMEOUT, TimeUnit.MILLISECONDS);
+
         Iterator<JsonNode> taskSummaries = response.asJson().elements();
         while (taskSummaries.hasNext()) {
           JsonNode taskSummary = taskSummaries.next();
@@ -473,13 +474,13 @@ public void run() {
             Iterator<JsonNode> heuristicsSummary = node.findValue("heuristicsummary").elements();
 
             HashMap<String, String> expectedHeuristics = new LinkedHashMap<String, String>();
-            expectedHeuristics.put("Mapper Data Skew", "None");
+            expectedHeuristics.put("Mapper Skew", "None");
             expectedHeuristics.put("Mapper GC", "None");
             expectedHeuristics.put("Mapper Time", "None");
             expectedHeuristics.put("Mapper Speed", "None");
             expectedHeuristics.put("Mapper Spill", "None");
             expectedHeuristics.put("Mapper Memory", "None");
-            expectedHeuristics.put("Reducer Data Skew", "None");
+            expectedHeuristics.put("Reducer Skew", "None");
             expectedHeuristics.put("Reducer Time", "None");
             expectedHeuristics.put("Reducer GC", "None");
             expectedHeuristics.put("Reducer Memory", "None");
@@ -788,13 +789,13 @@ private void testRestSearchGeneric(Iterator<JsonNode> searchNode) {
 
         Iterator<JsonNode> heuristicsSummary = node.findValue("heuristicsummary").elements();
         HashMap<String, String> expectedHeuristics = new LinkedHashMap<String, String>();
-        expectedHeuristics.put("Mapper Data Skew", "None");
+        expectedHeuristics.put("Mapper Skew", "None");
         expectedHeuristics.put("Mapper GC", "None");
         expectedHeuristics.put("Mapper Time", "None");
         expectedHeuristics.put("Mapper Speed", "None");
         expectedHeuristics.put("Mapper Spill", "None");
         expectedHeuristics.put("Mapper Memory", "None");
-        expectedHeuristics.put("Reducer Data Skew", "None");
+        expectedHeuristics.put("Reducer Skew", "None");
         expectedHeuristics.put("Reducer Time", "None");
         expectedHeuristics.put("Reducer GC", "None");
         expectedHeuristics.put("Reducer Memory", "None");
diff --git a/web/tests/integration/components/heuristic-details-list-test.js b/web/tests/integration/components/heuristic-details-list-test.js
index 1eeea899d..9287d2791 100644
--- a/web/tests/integration/components/heuristic-details-list-test.js
+++ b/web/tests/integration/components/heuristic-details-list-test.js
@@ -69,6 +69,6 @@ test('Test for heuristic-details', function(assert) {
 
   this.render(hbs`{{heuristic-details-list heuristic-details=heuristic-details}}`);
 
-  assert.equal(this.$().text().trim().split("\n").join("").replace(/ /g, ''), 'MapperDataSkewSeverity:NoneGroupA4tasks@443MBavgGroupB53tasks@464MBavgNumberoftasks57MapperGCSeverity:NoneAvgtaskCPUtime(ms)27565AvgtaskGCtime(ms)885Avgtaskruntime(ms)40890Numberoftasks57TaskGC/CPUratio0.03210593143479049');
+  assert.equal(this.$().text().trim().split("\n").join("").replace(/ /g, ''), 'MapperSkewSeverity:NoneGroupA4tasks@443MBavgGroupB53tasks@464MBavgNumberoftasks57MapperGCSeverity:NoneAvgtaskCPUtime(ms)27565AvgtaskGCtime(ms)885Avgtaskruntime(ms)40890Numberoftasks57TaskGC/CPUratio0.03210593143479049');
 
 });
diff --git a/web/tests/integration/components/heuristics-summary-test.js b/web/tests/integration/components/heuristics-summary-test.js
index ba46d6629..1a005e926 100644
--- a/web/tests/integration/components/heuristics-summary-test.js
+++ b/web/tests/integration/components/heuristics-summary-test.js
@@ -70,6 +70,6 @@ test('Tests for the rendering of heuristics-summary component', function (assert
   ]);
   this.render(hbs`{{heuristics-summary heuristics=heuristics}}`);
 
-  assert.equal(this.$().text().trim().split("\n").join("").replace(/ /g, ''), 'MapperDataSkewMapperGCMapperTimeMapperSpeedMapperSpillMapperMemoryReducerDataSkewReducerGCReducerTimeReducerMemoryShuffle&Sort');
+  assert.equal(this.$().text().trim().split("\n").join("").replace(/ /g, ''), 'MapperSkewMapperGCMapperTimeMapperSpeedMapperSpillMapperMemoryReducerSkewReducerGCReducerTimeReducerMemoryShuffle&Sort');
 
 });
diff --git a/web/tests/integration/components/single-heuristic-detail-test.js b/web/tests/integration/components/single-heuristic-detail-test.js
index 1da84d698..f56807a9b 100644
--- a/web/tests/integration/components/single-heuristic-detail-test.js
+++ b/web/tests/integration/components/single-heuristic-detail-test.js
@@ -24,7 +24,7 @@ moduleForComponent('single-heuristic-detail', 'Integration | Component | single
 test('it renders', function(assert) {
 
   this.set("yarnappheuristicresult", {
-    name: "Mapper Data Skew",
+    name: "Mapper Skew",
     severity: "None",
     details: [
       {