Yesterday at MW Summit there were some non-MariaDB options tossed aorund. They were:

More Hadoop usage than current efforts.

TokuMX http://www.tokutek.com/tokumx-for-mongodb/ (Sean)

No data yet on whether any or all are useful or not. Druid is probably the most established of the bunch. TokuMX is a MongoDB clone using TokuDB under the hood, the tech we already use to make analytics-store not explode replicating all shards.

If anyone is keen to experiment I think they should speak up and ask for hardware. Ops has some misc boxes around, plus a number of ex-MariaDB Dell R510's that might suit experiementation.

BR
Sean