YARN-10279. Avoid unnecessary QueueMappingEntity creations. Contributed by Marton Hudaky

(cherry picked from commit 6a8fd73b273629d0c7c071cf4d090f67d9b96fe4)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/QueuePlacementRuleUtils.java

@@ -74,12 +74,7 @@ public final class QueuePlacementRuleUtils {
       validateQueueMappingUnderParentQueue(queueManager.getQueue(
           mapping.getParentQueue()), mapping.getParentQueue(),
           mapping.getFullPath());
-      return QueueMapping.QueueMappingBuilder.create()
-          .type(mapping.getType())
-          .source(mapping.getSource())
-          .parentQueue(mapping.getParentQueue())
-          .queue(mapping.getQueue())
-          .build();
+      return mapping;
     }
 
     return null;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/UserGroupMappingPlacementRule.java

@@ -487,24 +487,14 @@ public class UserGroupMappingPlacementRule extends PlacementRule {
         && (mapping.getParentQueue().equals(PRIMARY_GROUP_MAPPING)
             || mapping.getParentQueue().equals(SECONDARY_GROUP_MAPPING))) {
       // dynamic parent queue
-      return QueueMappingBuilder.create()
-          .type(mapping.getType())
-          .source(mapping.getSource())
-          .queue(mapping.getQueue())
-          .parentQueue(mapping.getParentQueue())
-          .build();
+      return mapping;
     } else if (mapping.hasParentQueue()) {
       //if parent queue is specified,
       // then it should exist and be an instance of ManagedParentQueue
       QueuePlacementRuleUtils.validateQueueMappingUnderParentQueue(
               queueManager.getQueue(mapping.getParentQueue()),
           mapping.getParentQueue(), mapping.getQueue());
-      return QueueMappingBuilder.create()
-          .type(mapping.getType())
-          .source(mapping.getSource())
-          .queue(mapping.getQueue())
-          .parentQueue(mapping.getParentQueue())
-          .build();
+      return mapping;
     }
 
     return null;