svn merge -c 1519681 merging from trunk to branch-2.1 to fix HDFS-5150.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1519684 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -64,6 +64,8 @@ Release 2.1.1-beta - UNRELEASED
     HDFS-5128. Allow multiple net interfaces to be used with HA namenode RPC
     server. (kihwal)
 
+    HDFS-5150. Allow per NN SPN for internal SPNEGO. (kihwal)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java

@@ -182,6 +182,7 @@ public class NameNode {
     DFS_NAMENODE_BACKUP_HTTP_ADDRESS_KEY,
     DFS_NAMENODE_BACKUP_SERVICE_RPC_ADDRESS_KEY,
     DFS_NAMENODE_USER_NAME_KEY,
+    DFS_NAMENODE_INTERNAL_SPNEGO_USER_NAME_KEY,
     DFS_HA_FENCE_METHODS_KEY,
     DFS_HA_ZKFC_PORT_KEY,
     DFS_HA_FENCE_METHODS_KEY