Riak is an open source, distributed database. Riak uses a simple key/value model for object storage. Objects in Riak consist of a unique key and a value, stored in a flat namespace called a bucket. You can store anything you want in Riak: text, images, JSON/XML/HTML documents, user and session data, backups, log files, and more. Each node in a Riak cluster is the same – containing a complete, independent copy of the Riak package. There is no “master.” This uniformity provides the basis for Riak’s fault-tolerance and scalability. Riak is written in Erlang, a language designed for massively scalable systems.
Low-Latency: Riak is designed to store data and serve requests predictably and quickly, even during peak times.
Availability: Riak replicates and retrieves data intelligently, making it available for read and write operations even in failure conditions.
Fault-Tolerance: Riak is fault-tolerant so you can lose access to nodes due to network partition or hardware failure and never lose data.
Operational Simplicity: Riak allows you to add machines to the cluster easily, without a large operational burden.
Scalability: Riak automatically distributes data around the cluster and yields a near-linear performance increase as capacity is added.