YARN-2241. ZKRMStateStore: On startup, show nicer messages if znodes already exist. (Robert Kanter via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1607475 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -193,6 +193,9 @@ Release 2.5.0 - UNRELEASED
     TestContainersMonitor#testContainerKillOnMemoryOverflow.
     (Anubhav Dhoot via kasha)
 
+    YARN-2241. ZKRMStateStore: On startup, show nicer messages if znodes already 
+    exist. (Robert Kanter via kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/recovery/ZKRMStateStore.java

@@ -279,20 +279,21 @@ public class ZKRMStateStore extends RMStateStore {
 
   private void createRootDir(final String rootPath) throws Exception {
     // For root dirs, we shouldn't use the doMulti helper methods
-    try {
-      new ZKAction<String>() {
-        @Override
-        public String run() throws KeeperException, InterruptedException {
+    new ZKAction<String>() {
+      @Override
+      public String run() throws KeeperException, InterruptedException {
+        try {
           return zkClient.create(rootPath, null, zkAcl, CreateMode.PERSISTENT);
+        } catch (KeeperException ke) {
+          if (ke.code() == Code.NODEEXISTS) {
+            LOG.debug(rootPath + "znode already exists!");
+            return null;
+          } else {
+            throw ke;
+          }
         }
-      }.runWithRetries();
-    } catch (KeeperException ke) {
-      if (ke.code() == Code.NODEEXISTS) {
-        LOG.debug(rootPath + "znode already exists!");
-      } else {
-        throw ke;
       }
-    }
+    }.runWithRetries();
   }
 
   private void logRootNodeAcls(String prefix) throws Exception {