Merge r1615270 from trunk. YARN-2343. Improve NMToken expire exception message. Contributed by Li Lu

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1615271 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -62,6 +62,8 @@ Release 2.6.0 - UNRELEASED
     YARN-1994. Expose YARN/MR endpoints on multiple interfaces. (Craig Welch,
     Milan Potocnik, Arpit Agarwal via xgong)
 
+    YARN-2343. Improve NMToken expire exception message. (Li Lu via jianhe)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/ContainerManagerImpl.java

@@ -514,6 +514,8 @@ public class ContainerManagerImpl extends CompositeService implements
       messageBuilder.append("\nThis token is expired. current time is ")
         .append(System.currentTimeMillis()).append(" found ")
         .append(containerTokenIdentifier.getExpiryTimeStamp());
+      messageBuilder.append("\nNote: System times on machines may be out of sync.")
+        .append(" Check system time and time zones.");
     }
     if (unauthorized) {
       String msg = messageBuilder.toString();