Support pools of ZooKeeper servers (more than one addr) #6
Description
From Java docs:
To create a ZooKeeper client object, the application needs to pass a connection string containing a comma separated list of host:port pairs, each corresponding to a ZooKeeper server. The instantiated ZooKeeper client object will pick an arbitrary server from the connectString and attempt to connect to it. If establishment of the connection fails, another server in the connect string will be tried (the order is non-deterministic, as we random shuffle the list), until a connection is established. The client will continue attempts until the session is explicitly closed.
Along those lines, also handle session expiry differently from errors during reconnect.