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lib/Apache/Hadoop/WebHDFS.pm  view on Meta::CPAN

 

=item * getdelegationtoken() - gets a delegation token from the namenode.  This token is stored within the WebHDFS object and automatically appended to each WebHDFS request.   Delegation tokens are used on grids with security enabled.
    
       $hdfsclient->getdelegationtoken();

=item * renewdelegationtoken()  - renews a delegation token from the namenode. 

       $hdfsclient->renewdelegationtoken();

=item * canceldelegationtoken() - informs the namenode to invalidate the delegation token as it's no longer needed.   When calling this method, the delegation token is also removed from the perl WebHDFS object.

       $hdfsclient->canceldelegationtoken();

=item * Open() - opens file on HDFS and returns it's content The only required value for Open() is 'file', all others are optional.  The values, 'offset', 'length', and 'buffersize', are meant to be sized in bytes.

        $hdfsclient->Open({ file=>'/path/to/my/hdfs/file',
                            offset=>'1024',    
                            length=>'2048',
                            buffersize=>'1024',
                           });