Maybe consider Clustrix...
I'd rather avoid the effort of converting to another database like Postgres--or the massive re-architecture required by NoSQL/KVS systems. It might be time to look at MySQL-compatible options that are emerging. The Clustrix guys (clustrix.com) talk about being drop-in compatible from an application/architecture perspective, while also being to provide relational functionality and ACID guarantees across their cluster which "scales on-line from 3 to tens and hundreds of nodes". Managing the cluster as a single, highly-available database would simplify application development. Would have to see this in action though...
Biting the hand that feeds IT
