MongoDB 1.6 has been released. This open source, NoSQL system from 10gen has been updated with two new features, auto-sharding and replica sets.
Sharding is the ability to subdivide and spread a very large data set across many servers but still continue doing high-speed data updates and retrievals, which speeds up response to queries and expands a databases data handling capabilities. MongoDBs automated sharding will set up a routing map in the database based on a key to each shard so that it knows where data is and can respond to a query or update.
Replica sets establish a hierarchy among the three nodes handling a data set, with one node the primary handler of the data and two others receiving replicated copies. Should the primary node be lost, then according to previously established criteria, a new primary node is chosen out of the two remaining and a new third copy of data is made. Replica sets also help increase the speed of updates to the database.