If you didn't close the file correctly then NameNode wouldn't be notified of the final size of the file. The file size is meta-data coming from NameNode.
On Tue, Apr 8, 2014 at 4:35 AM, Tao Xiao <[email protected]> wrote: > I wrote some data into a file using MultipleOutputs in mappers. I can see > the contents in this file using "hadoop fs -ls <file>", but its size is > reported as zero by the command "hadoop fs -du <file>" or "hadoop fs -ls > <file>" , as follows: > > -rw-r--r-- 3 hadoop hadoop 0 2014-04-07 22:06 > /test/xt/out/2014-01-20/-m-00000 > > BTW, when I download this file from HDFS to local file system, I can see > the correct size. Why is it reported as zero size in hadoop CLI? > > >
