code: public static Map resetZKConfig(Map conf, String clusterName) {
          ClusterConfig nimbus = clusterConfig.get(clusterName);
          if (nimbus == null) return conf;
          conf.put(Config.STORM_ZOOKEEPER_ROOT, nimbus.getZkRoot());
          conf.put(Config.STORM_ZOOKEEPER_SERVERS, nimbus.getZkServers());
          conf.put(Config.STORM_ZOOKEEPER_PORT, nimbus.getZkPort());
          return conf;
      }
docs: to get nimbus client, we should reset ZK config