我正在设置我的memcached服务器，并且正在研究如果我的一台服务器出现故障，如何可以实现正常运行时间。我使用memcacheD扩展（2.2.0）
以下是我要使用的代码（Haven尚未部署）。我对以下几行有疑问。
session.save_handler = memcached
#2 servers; which one is the replica? What happens is the replica fails? Does it matter which one fails?
session.save_path = "192.168.134.38:11211,192.168.134.234:11211"
memcached.sess_consistent_hash=1
#What does this actually do?
memcached.sess_number_of_replicas=1
#Do I need this?
memcached.sess_binary=1