1. What is the the timeout between sending a PING messages from LEADER
to FOLLOWER? Is it equal to half of tickTime?
2. What is reconnection timeout with respect to clients? Is it equal to
(session expiration time / total zookeeper servers)?
3. How a FOLLOWER determines that the current LEADER is down or not? Is
it through a Heartbeat expiry? From tests it looks like that as soon as
LEADER is down, an exception is fired in every FOLLOWER by failing to read
an interger(length of the message)