I tried Accumulo on QFS today. It can be a drop-in replacement for HDFS. http://quantcast.github.io/qfs/
I sent a note to the QFS dev team on my results. https://groups.google.com/forum/#!topic/qfs-devel/VT9ROYrn1tg QFS was very easy to start and play with. Hopefully someone will answer my questions and we can have another file system option (MapR should already work). -Eric
