Twemproxy is a fast and lightweight proxy for memcached and redis protocol, developped by twitter. It was primarily built to reduce the connection count on the backend caching servers. You can use twemproxy + Redis for load balance, hight availability, etc.
SSDB database supports Redis protocol, so you can use Twemproxy + SSDB as Twemproxy + Redis, or even Twemproxy + SSDB + Redis.
Twemproxy + SSDB are already work online for production environment.