Why is homebrew Hadoop 2.3 not working OSX Mavericks?
Based on the first line of the second message,
"14/05/05 21:19:27 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable"
I suppose that you're running hadoop in a 64 bit operating system. Hadoop is built from default in a 32 bit system, I had the same issue and the same message. What you have to do is re-build hadoop from the source on your system.
I suggest you to use the guide below, it's for the 2.2 version but it's ok for the 2.3 version too
http://csrdu.org/nauman/2014/01/23/geting-started-with-hadoop-2-2-0-building/
Or the official guide
http://hadoop.apache.org/docs/r2.3.0/hadoop-project-dist/hadoop-common/NativeLibraries.html#Build