public boolean checkLogin(IClientSession session) {
    boolean isLoggedIn = session != null && session.isLogin();

    if (!isLoggedIn) {
      LOGGER.info("{}: Not login. ", IoTDBConstant.GLOBAL_DB_NAME);
    }

    return isLoggedIn;
  }
Check whether current user has logged in.

@return true: If logged in; false: If not logged in
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/SessionManager.java