private String getRootWorkingDir() {
    if (Strings.isNullOrEmpty(rootWorkingDir)) {
      rootWorkingDir = HiveConf.getVar(getConf(), HiveConf.ConfVars.DRUID_WORKING_DIR);
    }
    return rootWorkingDir;
  }
This function checks the load status of Druid segments by polling druid coordinator.
@param segments List of druid segments to check for
druid-handler/src/java/org/apache/hadoop/hive/druid/DruidStorageHandler.java