Voldemort is a distributed key-value storage system:
Data is automatically replicated over multiple servers.
Data is automatically partitioned so each server contains only a subset of the total data
Provides tunable consistency (strict quorum or eventual consistency)
Server failure is handled transparently
Pluggable Storage Engines -- BDB-JE, MySQL, Read-Only
Pluggable serialization -- Protocol Buffers, Thrift, Avro and Java Serialization
Data items are versioned to maximize data integrity in failure scenarios without compromising availability of the system
Each node is independent of other nodes with no central point of failure or coordination
Good single node performance: you can expect 10-20k operations per second depending on the machines, the network, the disk system, and the data replication factor
Support for pluggable data placement strategies to support things like distribution across data centers that are geographically far apart.