[ 
https://issues.apache.org/jira/browse/MAPREDUCE-3772?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13508108#comment-13508108
 ] 

Priyo Mustafi commented on MAPREDUCE-3772:
------------------------------------------

In that case for current releases we should send out a very visible warning in 
the mapreduce output when somebody attempts to use the baseOutputPath with a 
fully qualified path which is outside main output along with the javadoc 
changes.  This way folks who are currently using this feature in the incorrect 
way are aware that there would be data-loss.  In a later release we should 
enforce it so whether somebody reads the javadoc in detail or not, they are 
never faced with data loss.  
                
> MultipleOutputs output lost if baseOutputPath starts with ../
> -------------------------------------------------------------
>
>                 Key: MAPREDUCE-3772
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3772
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: client
>    Affects Versions: 0.20.2
>            Reporter: Radim Kolar
>            Assignee: Harsh J
>         Attachments: MAPREDUCE-3772.patch
>
>
> Lets say you have output directory set:
> FileOutputFormat.setOutputPath(job, "/tmp/multi1/out");
> and want to place output from MultipleOutputs into /tmp/multi1/extra
> I expect following code to work:
> mos = new MultipleOutputs<Text, IntWritable>(context);
> mos.write(new Text("zrr"), value, "../extra/");
> but no Exception is throw and expected output directory /tmp/multi1/extra 
> does not even exists. All data written to this output vanish without trace.
> To make it work fullpath must be used
> mos.write(new Text("zrr"), value, "/tmp/multi1/extra/");
> Output is listed in statistics from MultipleOutputs correctly:
>         org.apache.hadoop.mapreduce.lib.output.MultipleOutputs
>                 ../gaja1/=13333 (* everything is lost *)
>                 /tmp/multi1/out/../ksd34/=13333 (* this using full path works 
> *)
>                 list1=6667

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to