Tarantool - Fast in Memory Database for HOT DATA 10 Dec 2015
I have stumbled across Tarantool database which seems to be a very fast storage for hot data. If you are looking for a very fast and efficient tool, check it out.
Tarantool is claiming to be about 30% faster than Redis.
Tarantool allows to write server side stored procedures with Lua, allowing to create in DB rest APIs.
Tarantool is not good for big (static/cold) data.
Since it is not always easy to separte cold data from hot data. They are working on an smart automatic solution that will analyze the patterns of data access and decide automatically which parts of data are cold and should be phased out to disk and which parts are hot and should be treated as such.