YARN-3487. CapacityScheduler scheduler lock obtained unnecessarily when calling getQueue (Jason Lowe via wangda)

hadoop-yarn-project/CHANGES.txt

@@ -238,6 +238,8 @@ Release 2.7.1 - UNRELEASED
   OPTIMIZATIONS
 
   BUG FIXES
+    YARN-3487. CapacityScheduler scheduler lock obtained unnecessarily when 
+    calling getQueue (Jason Lowe via wangda)
 
 Release 2.7.0 - UNRELEASED
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacityScheduler.java

@@ -642,7 +642,7 @@ public class CapacityScheduler extends
     return queue;
   }
 
-  public synchronized CSQueue getQueue(String queueName) {
+  public CSQueue getQueue(String queueName) {
     if (queueName == null) {
       return null;
     }
@@ -940,11 +940,7 @@ public class CapacityScheduler extends
       boolean includeChildQueues, boolean recursive) 
   throws IOException {
     CSQueue queue = null;
-
-    synchronized (this) {
-      queue = this.queues.get(queueName); 
-    }
-
+    queue = this.queues.get(queueName);
     if (queue == null) {
       throw new IOException("Unknown queue: " + queueName);
     }