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https://issues.apache.org/jira/browse/FLINK-1433?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14291582#comment-14291582
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ASF GitHub Bot commented on FLINK-1433:
---------------------------------------

Github user rmetzger commented on the pull request:

    https://github.com/apache/flink/pull/337#issuecomment-71429315
  
    It depends on what the user does with the `HADOOP_CLASSPATH`.
    In my understanding, it is meant as a variable for adding 3rd party jar 
files to Hadoop. The jar files of hadoop are added to the `CLASSPATH` variable 
in the `libexec/hadoop-config.sh` script. There, you see variables like 
`HADOOP_COMMON_LIB_JARS_DIR`, `HDFS_LIB_JARS_DIR`, `YARN_LIB_JARS_DIR`, ... 
being added to the CLASSPATH. In the very last step, they add the 
HADOOP_CLASSPATH variable (by default to the end of the classpath, but there is 
an additional option to put it in front of it).
    
    I found that we need to add this on Google Compute Engine's Hadoop 
deployment. They have their Google Storage configured by default but it 
currently doesn't work in non-yarn setups because the Google Storage jar is not 
in our classpath. On these clusters, the `HADOOP_CLASSPATH` variable contains 
the path to the storage-jar.


> Add HADOOP_CLASSPATH to start scripts
> -------------------------------------
>
>                 Key: FLINK-1433
>                 URL: https://issues.apache.org/jira/browse/FLINK-1433
>             Project: Flink
>          Issue Type: Improvement
>            Reporter: Robert Metzger
>             Fix For: 0.8.1
>
>
> With the Hadoop file system wrapper, its important to have access to the 
> hadoop filesystem classes.
> The HADOOP_CLASSPATH seems to be a standard environment variable used by 
> Hadoop for such libraries.
> Deployments like Google Compute Cloud set this variable containing the 
> "Google Cloud Storage Hadoop Wrapper". So if users want to use the Cloud 
> Storage in an non-yarn environment, we need to address this issue.



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