This is so far an attempt to write "reactive" client in java for VoltDB.
VoltDB is a translytical, in-memory database for modern applications requring an unprecedented combination of data scale, volume, and accuracy. VoltDB is used today for traditional high performance applications such as capital markets data feeds, financial trade, telco record streams and sensor-based distribution systems. It's also used in emerging applications like wireless, online gaming, fraud detection, digital ad exchanges and micro transaction systems.
Things are "reactive" these days and it'd a nice addition to to have reactive client for VoltDB ecosystem.
Updates are coming :)