public TSStatus callSpecialProcedure(TTestOperation operation) {
    switch (operation) {
      case TEST_PROCEDURE_RECOVER:
        return configManager.getProcedureManager().createManyDatabases();
      case TEST_SUB_PROCEDURE:
        return configManager.getProcedureManager().testSubProcedure();
      default:
        String msg = String.format("operation %s is not supported", operation);
        LOGGER.error(msg);
        throw new UnsupportedOperationException(msg);
    }
  }
ConfigNodeRPCServer exposes the interface that interacts with the DataNode
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/service/thrift/ConfigNodeRPCServiceProcessor.java