I have set up a 3 node hadoop cluster (using HDP 1.1). Namenode is being run as hdfs user and the jobtracker is being run as mapred user (both belong to supergroup). I am currently trying to run a MR job as root and it gives me the following error :
2012-10-09 10:06:31,233 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:root cause:org.apache.hadoop.security.AccessControlException: Permission denied: user=root, access=READ_EXECUTE, inode=”system”:mapred:supergroup:rwx——
This error arises when the mr job tries to write into the /tmp/hadoop-mapred/mapred/system directory. This directory has permission 700. To overcome this error I tried setting permissions of this directory to 700. But the hadoop framework keeps complaining and tells me that I have to set the permission of this directory back to 700.
hadoop dfs -ls /tmp/hadoop-mapred/mapred/
Found 2 items
drwxrwxrwx – root supergroup 0 2012-10-09 10:03 /tmp/hadoop-mapred/mapred/staging
drwx—— – mapred supergroup 0 2012-10-09 10:03 /tmp/hadoop-mapred/mapred/system
Please let me know what I’m doing wrong here. Can’t seem to run a map reduce job as root.