[[ https://github.com/linkedin/ambry | ambry ]] is a distributed object store that supports storage of trillion of small immutable objects (50K -100K) as well as billions of large objects. It was specifically designed to store and serve media objects in web companies. However, it can be used as a general purpose storage system to store DB backups, search indexes or business reports.
A [2014 paper](http://publish.illinois.edu/assured-cloudcomputing/files/2014/03/Ambry-LinkedIns-Scalable-GeoDistributed-Object-Store.pdf) describes the design of ambry.