Redis is a key-value database that stands out from the crowd. It is not just another key-value database as it provides atomic and non-blocking operations on its keys and values. In Redis the values can be either primitives, sets or lists. Most other key-value databases allow only simple values like strings or bytes. There are commands to perform complex operations on these data structures, most in constant time. It is therefore not unreasonable to think of Redis as a data structures server.

The dataset can be replicated using a master-slave setup and also be distributed across a set of servers using consistent hashing.

The server provides blazing performance as most operations are non-blocking and the entire dataset is kept in-memory. Performance tests have shown results of 10000 SETs/second, 81000 GETs/second on an entry level Linux box.

Redis is open source, and the database server and clients are being hosted on Google Code. The project is aiming for a final 1.0 release mid June 2009.

In the presentation we'll take a look at the characteristics of the database server and the operations that it provides including demos of how it works in practice. The Java client will also be reviewed.