(cherry picked from commit b0dc291961410b6ac2b275cdcff4b95d75727e8d) Conflicts: hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/DatanodeHttpServer.java (cherry picked from commit cd578fa289252b0ae1e27f7e7b097cceeb2c30ff)