protected final void populateCache(PathChildrenCache instancesCache, boolean doInvokeListeners) {
    for (ChildData childData : instancesCache.getCurrentData()) {
      byte[] data = getWorkerData(childData, workerNodePrefix);
      if (data == null) continue;
      String nodeName = extractNodeName(childData);
      if (!isLlapWorker(nodeName, workerNodePrefix)) continue;
      int ephSeqVersion = extractSeqNum(nodeName);
      try {
        ServiceRecord srv = encoder.fromBytes(childData.getPath(), data);
        InstanceType instance = createServiceInstance(srv);
        addToCache(childData.getPath(), instance.getHost(), instance);
        if (doInvokeListeners) {
          for (ServiceInstanceStateChangeListener<InstanceType> listener : stateChangeListeners) {
            listener.onCreate(instance, ephSeqVersion);
          }
        }
      } catch (IOException e) {
        LOG.error("Unable to decode data for zkpath: {}." +
            " Ignoring from current instances list..", childData.getPath());
      }
    }
  }
Get the ensemble server addresses from the configuration. The format is: host1:port,
host2:port..

@param conf configuration
llap-client/src/java/org/apache/hadoop/hive/registry/impl/ZkRegistryBase.java