because in your permission set, the other role can not write the temp directory. and user3 is not in the same group with user2.
heyongqiang 2008-07-09 发件人： Joman Chu 发送时间： 2008-07-09 13:06:51 收件人： [email protected] 抄送： 主题： File permissions issue Hello, On a cluster where I run Hadoop, it seems that the temp directory created by Hadoop (in our case, /tmp/hadoop/) gets its permissions set to "drwxrwxr-x" owned by the first person that runs a job after the Hadoop services are started. This causes file permissions problems as we try to run jobs. For example, user1:user1 starts Hadoop using ./start-all.sh. Then user2:user2 runs a Hadoop job. Temp directories (/tmp/hadoop/) are now created in all nodes in the cluster owned by user2 with permissions "drwxrwxr-x". Now user3:user3 tries to run a job and gets the following exception: java.io.IOException: Permission denied at java.io.UnixFileSystem.createFileExclusively(Native Method) at java.io.File.checkAndCreate(File.java:1704) at java.io.File.createTempFile(File.java:1793) at org.apache.hadoop.util.RunJar.main(RunJar.java:115) at org.apache.hadoop.mapred.JobShell.run(JobShell.java:194) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79) at org.apache.hadoop.mapred.JobShell.main(JobShell.java:220) Why does this happen and how can we fix this? Our current stop gap measure is to run a job as the user that started Hadoop. That is, in our example, after user1 starts Hadoop, user1 runs a job. Everything seems to work fine then. Thanks, Joman Chu
