A list of host/port pairs to use to establish the initial connection to the Kafka
cluster used for licensing. All servers in the cluster will be discovered from
the initial connection. The list should be in the following format:
host1:port1,host2:port2,...
Since these servers are just used for the initial connection to discover the
full cluster membership (which may change dynamically), this list need not
contain the full set of servers (you may want more than one, though, in case a
server is down).