better memory model over Memcache. If one of our memcached servers dies, that data is gone. Redis can write to disk, optionally. We mostly use redis and memcach

better memory model over Memcache. If one of our memcached servers dies, that data is gone. Redis can write to disk, optionally. We mostly use redis and memcache as a cache to save load from the db. Even with dozens and dozens of dedicated read hosts, we can knock over our dbs if we are not caching data.