Clustering : Switching behavior to IsolatedLeader can cause disruption on transaction processing

When a Leader does not get responses from a majority of it's peers in the election timeout period the Leader switches to the IsolatedLeader behavior. When this happens transactions which are open against the current leader may timeout.

To reproduce follow the steps below,

1. On a single machine configure the controller as the first member in a 3 node cluster.
2. On the same machine run the data store simulator as member-2 and member-3
3. Once the simulators start getting append entries connect mininet to the controller attach mininet to it with 127 switches
4. Watch the log. Soon you will start seeing timeout exceptions.