[jira] [Commented] (PIG-5360) Pig sets working directory of input file systems causes exception thrown

["Xuzhou Yin (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-5360?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16809237#comment-16809237 ] 

Xuzhou Yin commented on PIG-5360:
---------------------------------

This issue has been opened for a while. It would be a great appreciate is anyone can take a look... Thanks a lot!

> Pig sets working directory of input file systems causes exception thrown
> ------------------------------------------------------------------------
>
>                 Key: PIG-5360
>                 URL: https://issues.apache.org/jira/browse/PIG-5360
>             Project: Pig
>          Issue Type: Bug
>          Components: impl
>    Affects Versions: 0.17.0
>            Reporter: Xuzhou Yin
>            Priority: Minor
>              Labels: patch
>             Fix For: 0.18.0
>
>         Attachments: PIG-5360.diff
>
>   Original Estimate: 504h
>  Remaining Estimate: 504h
>
> {color:#000000}In getSplits() method in PigInputFormat, Pig is trying to set the working directory of input File System to jobContext.getWorkingDirectory(), which is always the default working directory of default file system (eg. hdfs://host:port/user/userId in case of HDFS) unless “mapreduce.job.working.dir” is explicitly set to non-default value. So if the input path uses non-default file system, then it will fail since it is trying to set the working directory of non-default file system to a HDFS path.{color}
> {color:#000000}The proposed change is to completely remove this logic of setting working directory. There are several reasons for doing so. {color}
> {color:#000000}Firstly, getSplits() is only supposed to return a list of input splits. It should not have side effects (especially doing so can potentially change the output path). Having InputFormat changes OutputFormat does not make much sense here.
> {color}
> {color:#000000}Secondly, there is inconsistency between the working directories of input and output file systems. if "mapreduce.job.working.dir" is set to non-default value, it will affect the output path only (if it is a relative path) because input path will be made qualified even before this logic.{color}
> {color:#000000}Thirdly, there is already a "CD" functionality that allows customers to change the working directory. However, this logic will overwrite the "CD" functionality if input and output paths both use default file system.{color}
> {color:#000000}Lastly, if customer has a sequence of jobs, changing the working directory may change the input paths of downstream jobs if the input paths are specified as relative{color}



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)