apache
/
hadoop
огледало от https://github.com/apache/hadoop.git


			
				
					
						
						
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<document xmlns="http://maven.apache.org/XDOC/2.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/XDOC/2.0 http://maven.apache.org/xsd/xdoc-2.0.xsd">
  <head>
    <title>DistCp</title>
  </head>
  <body>
    <section name="Overview">
      <p>
        DistCp (distributed copy) is a tool used for large inter/intra-cluster
      copying. It uses Map/Reduce to effect its distribution, error
      handling and recovery, and reporting. It expands a list of files and
      directories into input to map tasks, each of which will copy a partition
      of the files specified in the source list.
      </p>
      <p>
       The erstwhile implementation of DistCp has its share of quirks and
       drawbacks, both in its usage, as well as its extensibility and
       performance. The purpose of the DistCp refactor was to fix these shortcomings,
       enabling it to be used and extended programmatically. New paradigms have
       been introduced to improve runtime and setup performance, while simultaneously
       retaining the legacy behaviour as default.
      </p>
      <p>
       This document aims to describe the design of the new DistCp, its spanking
       new features, their optimal use, and any deviance from the legacy
       implementation.
      </p>
    </section>
  </body>
</document>