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MapReduce, mail # user - RE: Permission problem


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Re: Permission problem
Arpit Gupta 2013-04-30, 14:47
Based on the logs your system dir is set to

> hdfs://devubuntu05:9000/data/hadoop/tmp/hadoop-mapred/mapred/system
what is your fs.default.name and hadoop.tmp.dir in core-site.xml set to?

--
Arpit Gupta
Hortonworks Inc.
http://hortonworks.com/

On Apr 30, 2013, at 7:39 AM, "Kevin Burton" <[EMAIL PROTECTED]> wrote:

>  
> Thank you.
>  
> mapred.system.dir is not set. I am guessing that it is whatever the default is. What should I set it to?
>  
> /tmp is already 777
>  
> kevin@devUbuntu05:~$ hadoop fs -ls /tmp
> Found 1 items
> drwxr-xr-x   - hdfs supergroup          0 2013-04-29 15:45 /tmp/mapred
> kevin@devUbuntu05:~$ hadoop fs -ls -d /tmp
> Found 1 items
> drwxrwxrwt   - hdfs supergroup          0 2013-04-29 15:45 /tmp
>  
> But notice that the mapred folder in the /tmp folder is 755.
> So I changed it:
>  
> kevin@devUbuntu05 $ hadoop fs -ls -d /tmp
> drwxrwxrwt   - hdfs supergroup          0 2013-04-29 15:45 /tmp
>  
> kevin@devUbuntu05 $ hadoop fs -ls -R /tmp        
> drwxr-xr-x   - mapred supergroup          0 2013-04-29 15:45 /tmp/mapred
> drwxr-xr-x   - mapred supergroup          0 2013-04-29 15:45 /tmp/mapred/system
>  
> I still get the errors in the log file:
>  
> 2013-04-30 09:35:11,609 WARN org.apache.hadoop.mapred.JobTracker: Failed to operate on mapred.system.dir (hdfs://devubuntu05:9000/data/hadoop/tmp/hadoop-mapred/mapred/system) because of permissions.
> 2013-04-30 09:35:11,609 WARN org.apache.hadoop.mapred.JobTracker: This directory should be owned by the user 'mapred (auth:SIMPLE)'
> 2013-04-30 09:35:11,609 WARN org.apache.hadoop.mapred.JobTracker: Bailing out ...
> . . . . .
> org.apache.hadoop.security.AccessControlException: Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxrwxr-x
> . . . . .
> Caused by: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.AccessControlException): Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxrwxr-x
> 2013-04-30 09:35:11,610 FATAL org.apache.hadoop.mapred.JobTracker: org.apache.hadoop.security.AccessControlException: Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxrwxr-x
> . . . . . .
>  
>  
> From: Arpit Gupta [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, April 30, 2013 9:25 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Permission problem
>  
> what is your mapred.system.dir set to in mapred-site.xml?
>  
> By default it will write to /tmp on hdfs.
>  
> So you can do the following
>  
> create /tmp on hdfs and chmod it to 777 as user hdfs and then restart jobtracker and tasktrackers.
>  
> In case its set to /mapred/something then create /mapred and chown it to user mapred.
>  
>
> --
> Arpit Gupta
> Hortonworks Inc.
> http://hortonworks.com/
>  
> On Apr 30, 2013, at 6:36 AM, "Kevin Burton" <[EMAIL PROTECTED]> wrote:
>
>
> To further complicate the issue the log file in (/var/log/hadoop-0.20-mapreduce/hadoop-hadoop-jobtracker-devUbuntu05.log) is owned by mapred:mapred and the name of the file seems to indicate some other lineage (hadoop,hadoop). I am out of my league in understanding the permission structure for hadoop hdfs and mr. Ideas?
>  
> From: Kevin Burton [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, April 30, 2013 8:31 AM
> To: [EMAIL PROTECTED]
> Cc: 'Mohammad Tariq'
> Subject: RE: Permission problem
>  
> That is what I perceive as the problem. The hdfs file system was created with the user ‘hdfs’ owning the root (‘/’) but for some reason with a M/R job the user ‘mapred’ needs to have write permission to the root. I don’t know how to satisfy both conditions. That is one reason that I relaxed the permission to 775 so that the group would also have write permission but that didn’t seem to help.
>  
> From: Mohammad Tariq [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, April 30, 2013 8:20 AM
> To: Kevin Burton
> Subject: Re: Permission problem
>  
> user?"ls" shows "hdfs" and the log says "mapred"..
>
> Warm Regards,
> Tariq