If you want to go the Erlang route (highly recommended, but be prepared for a bit of a learning curve if you are not familiar with functional programming) then

If you want to go the Erlang route (highly recommended, but be prepared for a bit of a learning curve if you are not familiar with functional programming) then you would do well to look at the Scalaris project (fault-tolerant, distributed, eventually consistent key-value store that can use paxos for consistent transactions) or the Kai project (similar scope and goals.) You can also probably get pretty far with the built-in mnesia database.