Riak CS is S3 compatible. I have a very similar problem and end up writing a python script that copies the files to cassandra and Nginx + Lua to serve them usi

Riak CS is S3 compatible. I have a very similar problem and end up writing a python script that copies the files to cassandra and Nginx + Lua to serve them using lua-resty-cassandra. The read/write throughput is still not as good as I was expecting though.