HDFS-6397. NN shows inconsistent value in deadnode count. Contributed by Mohammad Kamrul Islam.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1595978 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10489. UserGroupInformation#getTokens and UserGroupInformation#addToken can lead to ConcurrentModificationException. Contributed by Robert Kanter.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1596020 13f79535-47bb-0310-9956-ffa450edef68