diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index 56cfd1335f..aa14dfbad4 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -200,6 +200,9 @@ Release 0.23.1 - Unreleased
     MAPREDUCE-3737. The Web Application Proxy's is not documented very well.
     (Robert Evans via mahadev)
 
+    MAPREDUCE-3699. Increased RPC handlers for all YARN servers to reasonable
+    values for working at scale. (Hitesh Shah via vinodkv)
+
   OPTIMIZATIONS
 
     MAPREDUCE-3567. Extraneous JobConf objects in AM heap. (Vinod Kumar
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java
index a1c4407f26..7b684c5b61 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java
@@ -412,7 +412,7 @@ public interface MRJobConfig {
   /** The number of threads used to handle task RPC calls.*/
   public static final String MR_AM_TASK_LISTENER_THREAD_COUNT =
     MR_AM_PREFIX + "job.task.listener.thread-count";
-  public static final int DEFAULT_MR_AM_TASK_LISTENER_THREAD_COUNT = 10;
+  public static final int DEFAULT_MR_AM_TASK_LISTENER_THREAD_COUNT = 30;
 
   /** How often the AM should send heartbeats to the RM.*/
   public static final String MR_AM_TO_RM_HEARTBEAT_INTERVAL_MS =
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml
index 5d02250c49..fc5b8b23f8 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml
@@ -1224,4 +1224,18 @@
     mapreduce.job.end-notification.max.retry.interval</description>
 </property>
 
+<property>
+  <name>yarn.app.mapreduce.am.job.task.listener.thread-count</name>
+  <value>30</value>
+  <description>The number of threads used to handle RPC calls in the 
+    MR AppMaster from remote tasks</description>
+</property>
+
+<property>
+  <name>yarn.app.mapreduce.am.scheduler.heartbeat.interval-ms</name>
+  <value>1000</value>
+  <description>The interval in ms at which the MR AppMaster should send
+    heartbeats to the ResourceManager</description>
+</property>
+
 </configuration>
diff --git a/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java b/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
index a030079779..f4cbf6e65b 100644
--- a/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
+++ b/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
@@ -90,7 +90,7 @@ public class YarnConfiguration extends Configuration {
   /** The number of threads used to handle applications manager requests.*/
   public static final String RM_CLIENT_THREAD_COUNT =
     RM_PREFIX + "client.thread-count";
-  public static final int DEFAULT_RM_CLIENT_THREAD_COUNT = 10;
+  public static final int DEFAULT_RM_CLIENT_THREAD_COUNT = 50;
 
   /** The Kerberos principal for the resource manager.*/
   public static final String RM_PRINCIPAL =
@@ -106,7 +106,7 @@ public class YarnConfiguration extends Configuration {
   /** Number of threads to handle scheduler interface.*/
   public static final String RM_SCHEDULER_CLIENT_THREAD_COUNT =
     RM_PREFIX + "scheduler.client.thread-count";
-  public static final int DEFAULT_RM_SCHEDULER_CLIENT_THREAD_COUNT = 10;
+  public static final int DEFAULT_RM_SCHEDULER_CLIENT_THREAD_COUNT = 50;
   
   /** The address of the RM web application.*/
   public static final String RM_WEBAPP_ADDRESS = 
@@ -184,7 +184,7 @@ public class YarnConfiguration extends Configuration {
   /** Number of threads to handle resource tracker calls.*/
   public static final String RM_RESOURCE_TRACKER_CLIENT_THREAD_COUNT =
     RM_PREFIX + "resource-tracker.client.thread-count";
-  public static final int DEFAULT_RM_RESOURCE_TRACKER_CLIENT_THREAD_COUNT = 10;
+  public static final int DEFAULT_RM_RESOURCE_TRACKER_CLIENT_THREAD_COUNT = 50;
   
   /** The class to use as the resource scheduler.*/
   public static final String RM_SCHEDULER = 
@@ -257,7 +257,7 @@ public class YarnConfiguration extends Configuration {
   /** Number of threads container manager uses.*/
   public static final String NM_CONTAINER_MGR_THREAD_COUNT =
     NM_PREFIX + "container-manager.thread-count";
-  public static final int DEFAULT_NM_CONTAINER_MGR_THREAD_COUNT = 5;
+  public static final int DEFAULT_NM_CONTAINER_MGR_THREAD_COUNT = 20;
   
   /** Number of threads used in cleanup.*/
   public static final String NM_DELETE_THREAD_COUNT = 
diff --git a/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/resources/yarn-default.xml b/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/resources/yarn-default.xml
index b9e5ea47e4..cea45798a7 100644
--- a/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/resources/yarn-default.xml
+++ b/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/resources/yarn-default.xml
@@ -67,7 +67,7 @@
   <property>
     <description>The number of threads used to handle applications manager requests.</description>
     <name>yarn.resourcemanager.client.thread-count</name>
-    <value>10</value>
+    <value>50</value>
   </property>
 
   <property>
@@ -90,7 +90,7 @@
   <property>
     <description>Number of threads to handle scheduler interface.</description>
     <name>yarn.resourcemanager.scheduler.client.thread-count</name>
-    <value>10</value>
+    <value>50</value>
   </property>
 
   <property>
@@ -179,7 +179,7 @@
   <property>
     <description>Number of threads to handle resource tracker calls.</description>
     <name>yarn.resourcemanager.resource-tracker.client.thread-count</name>
-    <value>10</value>
+    <value>50</value>
   </property>
 
   <property>
@@ -244,7 +244,7 @@
   <property>
     <description>Number of threads container manager uses.</description>
     <name>yarn.nodemanager.container-manager.thread-count</name>
-    <value>5</value>
+    <value>20</value>
   </property>
 
   <property>