Product: Lightcloud - Key-Value Database
Their website does a nice job explaining the system:
Built on Tokyo Tyrant. One of the fastest key-value databases [benchmark]. Tokyo Tyrant has been in development for many years and is used in production by Plurk.com, mixi.jp and scribd.com (to name a few)... Great performance (comparable to memcached!) Can store millions of keys on very few servers - tested in production Scale out by just adding nodes Nodes are replicated via master-master replication. Automatic failover and load balancing is supported from the start Ability to script and extend using Lua. Included extensions are incr and a fixed list Hot backups and restore: Take backups and restore servers without shutting them down LightCloud manager can control nodes, take backups and give you a status on how your nodes are doing Very small foot print (lightcloud client is around ~500 lines and manager about ~400) Python only, but LightCloud should be easy to port to other languages