code: public String getActiveServerAddress() {
          CuratorFramework client = curatorFactory.clientInstance();
          String serverAddress = null;
          try {
              HAConfiguration.ZookeeperProperties zookeeperProperties =
                      HAConfiguration.getZookeeperProperties(configuration);
              byte[] bytes = client.getData().forPath(getZnodePath(zookeeperProperties));
              serverAddress = new String(bytes, Charset.forName("UTF-8"));
          } catch (Exception e) {
              LOG.error("Error getting active server address", e);
          }
          return serverAddress;
      }
docs: Retrieve state of the active server instance.
  
  This method reads the active server location from the shared node in Zookeeper.
  @return the active server's address and port of form http://host-or-ip:port