Hi, I setup Hadoop 2.2 cluster with NameNode HA. How to upgrade it to 2.4? I try to upgrade according to http://hadoop.apache.org/docs/r2.4.0/hadoop-project-dist/hadoop-hdfs/HdfsRollingUpgrade.html, but can't works. Is there a detailed step by step guide include when to shutdown namenode or when to change env variable like HADOOP_HOME in which step? There are two mode to upgrade, cluster running or cluster stopped. Either one is ok. Thanks.
Regards, Jason
