I have documented my issue here:

When I use the ZooKeeper client to connect to a server, it takes the server
address from the "-server" command line argument, looks up the IP address,
and then tried to find the host name based on that IP address.

If you're using an Amazon EC2 instance, then instead of getting something
like mysookeeperhost.mydomain.com for the host name, instead something like
ec2-35-169-37-216.compute-1.amazonaws.com will be returned.

Is there an option to use the server address from the command line as the
host name?

NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB