I am quite new for zookeeper port through which I am coming across from past few days.
I introduced with zookeeper port keyword at two occasion:
Zookeeper is used in distributed applications mainly for configuration management and high availability operations. Zookeeper does this by a Master-Slave architecture. Neo4j and VoltDb might be using zookeeper for this purpose
Coming to the ports understanding : suppose u have 3 servers for zookeepers ... You need to mention in configuration as
clientPort=2181 server.1=zookeeper1:2888:3888 server.2=zookeeper2:2888:3888 server.3=zookeeper3:2888:3888
Out of these one server will be the master and rest all will be slaves.If any server goes OFF then zookeeper elects leader automatically .
Servers listen on three ports: 2181 for client connections; 2888 for follower connections, if they are the leader; and 3888 for other server connections during the leader election phase .