Accessing directory of small files as one file
hadoop fs -getmerge &lt;hdfs-output-directory&gt; &lt;local-file&gt; 


This command can be used to concatenate the HDFS files into a single local file.

Ref : http://hadoop.apache.org/docs/r2.7.0/hadoop-project-dist/hadoop-common/FileSystemShell.html#getmerge