MongoDB 1.6 adds auto-sharding and replica sets
NoSQL document store MongoDB's new release from 10gen and the MongoDB community now offers automated horizontal scaling, high availability, automatic failover, replica sets and auto-sharding. MongoDB 1.6 is the fourth stable release of the NoSQL database.
Replica sets are new in 1.6, offering a new method for replicating databases and support automatic failover, automatic node recovery and operations with multiple data centres. Replica sets in turn make the automated horizontal scaling possible in the form of auto-sharding.
Sharding is a technique where a developer splits a database across multiple servers, with each server supplying a particular set of rows. Normally, the developer has to work out a strategy for administering this process, but with MongoDB 1.6's auto-sharding the splitting is handled by a combination of shard servers, config servers and a client facing Mongo server. Replica sets functionality is used to keep the shard servers up to date and handle nodes being added or failing.
UK start-up and MongoDB user BoxedIce has produced a number of videos on the new features and gives examples of how to configure an auto-sharding system, in the company's blog. Companies such as foursquare and bit.ly have been using the new functionality in production for some months.
MongoDB is available under the GNU AGPL3 with commercial licences available from 10gen. MongoDB drivers for Python, PHP, Ruby, Java and Perl are available under an Apache 2.0 licence. It can be downloaded from the Mongodb.org site as source or binaries for Linux, Solaris, Windows or Mac OS X.