Format for using Hadoop archives with MapReduce
To use Hadoop Archives with MapReduce, you must reference files differently than you
would with the default file system. If you have a Hadoop Archive stored in HDFS in
/user/zoo/foo.har, you must specify the input directory as
har:///user/zoo/foo.har to use it as a MapReduce input.
Because Hadoop Archives are exposed as a file system, MapReduce can use all of the logical input files in Hadoop Archives as input.