Doozer is a network service. A handful of machines (usually three, five, or seven) each run one doozer server process. These processes communicate with each other using a standard fully-consistent distributed consensus algorithm. Clients dial in to one or more of the doozer servers, issue commands, such as GET, SET, and WATCH, and receive responses.
Each doozerd process has a complete copy of the datastore and serves both read and write requests; there is no distinguished "master" or "leader". Doozer is designed to store data that fits entirely in memory; it never writes data to permanent files. A separate tool provides durable storage for backup and recovery.