diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java
index 357cbf3f152..3bd6a0fe43a 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java
@@ -1864,8 +1864,8 @@ public class ResourceManager extends CompositeService
       confStore.initialize(conf, conf, rmContext);
       confStore.format();
     } else {
-      System.out.println("Scheduler Configuration format only " +
-          "supported by MutableConfScheduler.");
+      System.out.println(String.format("Scheduler Configuration format only " +
+          "supported by %s.", MutableConfScheduler.class.getSimpleName()));
     }
   }
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
index 1dac043ae16..26c921796b3 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
@@ -2678,7 +2678,7 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
     } else {
       return Response.status(Status.BAD_REQUEST)
           .entity("Scheduler Configuration format only supported by " +
-          "MutableConfScheduler.").build();
+              MutableConfScheduler.class.getSimpleName()).build();
     }
   }
 
@@ -2727,8 +2727,8 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
                   .build();
       }
     } else {
-      String errorMsg = "Configuration change validation only supported by " +
-              "MutableConfScheduler.";
+      String errorMsg = String.format("Configuration change validation only supported by %s.",
+          MutableConfScheduler.class.getSimpleName());
       LOG.warn(errorMsg);
       return Response.status(Status.BAD_REQUEST)
               .entity(errorMsg)
@@ -2823,10 +2823,11 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
           .build();
     } else {
       return Response.status(Status.BAD_REQUEST).entity(
-          "This API only supports to retrieve scheduler configuration"
-              + " from a mutable-conf scheduler, underneath scheduler "
-              + scheduler.getClass().getSimpleName()
-              + " is not an instance of MutableConfScheduler")
+              String.format("This API only supports to retrieve scheduler configuration"
+                  + " from a mutable-conf scheduler, underneath scheduler %s"
+                  + " is not an instance of %s",
+                  scheduler.getClass().getSimpleName(),
+                  MutableConfScheduler.class.getSimpleName()))
           .build();
     }
   }
@@ -2858,8 +2859,8 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
       }
     } else {
       return Response.status(Status.BAD_REQUEST)
-          .entity("Configuration Version only supported by "
-          + "MutableConfScheduler.").build();
+          .entity(String.format("Configuration Version only supported by %s.",
+              MutableConfScheduler.class.getSimpleName())).build();
     }
   }
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServices.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServices.java
index d5d534395b5..ce9de643744 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServices.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServices.java
@@ -75,6 +75,7 @@ import org.apache.hadoop.yarn.server.resourcemanager.*;
 import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppMetrics;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
@@ -1003,8 +1004,8 @@ public class TestRMWebServices extends JerseyTestBase {
     Assert.assertEquals(Status.BAD_REQUEST
             .getStatusCode(), response.getStatus());
     Assert.assertTrue(response.getEntity().toString()
-            .contains("Configuration change validation only supported by"
-                    +" MutableConfScheduler."));
+            .contains(String.format("Configuration change validation only supported by %s.",
+                MutableConfScheduler.class.getSimpleName())));
   }
 
   @Test