NewPooledObject return the pack struct for addr and the appropriate redis pool.

NewRoundRobinPool return a round-robin redis client pool specified by zk client and redis options.

PooledObject is a pack struct for addr and the appropriate redis pool.

ProxyInfo is represent the redis proxy instance is online or not.

RoundRobinPool is a round-robin redis client pool for connecting multiple codis proxies based on zookeeper-go and redis-go.