@Override
  public int compareTo(Address that) {
    int compare = this.getHostName().compareTo(that.getHostName());
    if (compare != 0) {
      return compare;
    }

    return this.getPort() - that.getPort();
  }
If hostname is a.b.c and the port is 123, return a:123 instead of a.b.c:123.
@return if host looks like it is resolved -- not an IP -- then strip the domain portion
        otherwise returns same as {@link #toString()}}
hbase-common/src/main/java/org/apache/hadoop/hbase/net/Address.java