diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 13a3c94f6e0..a2bfa1dc0a3 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -26,6 +26,9 @@ Release 2.7.0 - UNRELEASED
     YARN-2641. Decommission nodes on -refreshNodes instead of next 
     NM-RM heartbeat. (Zhihai Xu via kasha)
 
+    YARN-2742. FairSchedulerConfiguration should allow extra spaces
+    between value and unit. (Wei Yan via kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerConfiguration.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerConfiguration.java
index a96952daaa8..32ef906a571 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerConfiguration.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerConfiguration.java
@@ -241,6 +241,7 @@ public class FairSchedulerConfiguration extends Configuration {
   public static Resource parseResourceConfigValue(String val)
       throws AllocationConfigurationException {
     try {
+      val = val.toLowerCase();
       int memory = findResource(val, "mb");
       int vcores = findResource(val, "vcores");
       return BuilderUtils.newResource(memory, vcores);
@@ -258,7 +259,7 @@ public class FairSchedulerConfiguration extends Configuration {
   
   private static int findResource(String val, String units)
     throws AllocationConfigurationException {
-    Pattern pattern = Pattern.compile("(\\d+) ?" + units);
+    Pattern pattern = Pattern.compile("(\\d+)\\s*" + units);
     Matcher matcher = pattern.matcher(val);
     if (!matcher.find()) {
       throw new AllocationConfigurationException("Missing resource: " + units);
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerConfiguration.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerConfiguration.java
index 3db87f6ea45..82b50a6c74d 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerConfiguration.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerConfiguration.java
@@ -39,6 +39,12 @@ public class TestFairSchedulerConfiguration {
         parseResourceConfigValue("2vcores,1024mb"));
     assertEquals(BuilderUtils.newResource(1024, 2),
         parseResourceConfigValue("1024mb,2vcores"));
+    assertEquals(BuilderUtils.newResource(1024, 2),
+        parseResourceConfigValue("1024   mb, 2    vcores"));
+    assertEquals(BuilderUtils.newResource(1024, 2),
+        parseResourceConfigValue("1024 Mb, 2 vCores"));
+    assertEquals(BuilderUtils.newResource(1024, 2),
+        parseResourceConfigValue("  1024 mb, 2 vcores  "));
   }
   
   @Test(expected = AllocationConfigurationException.class)