code: static boolean shouldRun(Configuration conf) {
      String nodeHealthScript = conf.get(HEALTH_CHECK_SCRIPT_PROPERTY);
      if (nodeHealthScript == null || nodeHealthScript.trim().isEmpty()) {
        return false;
      }
      File f = new File(nodeHealthScript);
      return f.exists() && f.canExecute();
    }
docs: Method used to determine if or not node health monitoring service should be
  started or not. Returns true if following conditions are met:
  
  <ol>
  <li>Path to Node health check script is not empty</li>
  <li>Node health check script file exists</li>
  </ol>
  
  @param conf
  @return true if node health monitoring service can be started.