This is why I like cascading [1]. It has a higher level API on Hadoop. It also works in local mode with little change. I've actually used out to do transformation work from local files (csv), join them into structured documents and dump them into ArangoDB. I liked it so much I wrote a third party library to work ArangoDB in Hadoop[2].
1 cascading.org/ 2 https://github.com/deusdat/guacaphant