private void loadTriggerProps(TrimProperties properties) {
    conf.setTriggerDir(properties.getProperty("trigger_lib_dir", conf.getTriggerDir()).trim());
    conf.setRetryNumToFindStatefulTrigger(
        Integer.parseInt(
            properties.getProperty(
                "stateful_trigger_retry_num_when_not_found",
                Integer.toString(conf.getRetryNumToFindStatefulTrigger()))));

    int tlogBufferSize =
        Integer.parseInt(
            properties.getProperty("tlog_buffer_size", Integer.toString(conf.getTlogBufferSize())));
    if (tlogBufferSize > 0) {
      conf.setTlogBufferSize(tlogBufferSize);
    }

    conf.setTriggerForwardMaxQueueNumber(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_max_queue_number",
                Integer.toString(conf.getTriggerForwardMaxQueueNumber()))));
    conf.setTriggerForwardMaxSizePerQueue(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_max_size_per_queue",
                Integer.toString(conf.getTriggerForwardMaxSizePerQueue()))));
    conf.setTriggerForwardBatchSize(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_batch_size",
                Integer.toString(conf.getTriggerForwardBatchSize()))));
    conf.setTriggerForwardHTTPPoolSize(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_http_pool_size",
                Integer.toString(conf.getTriggerForwardHTTPPoolSize()))));
    conf.setTriggerForwardHTTPPOOLMaxPerRoute(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_http_pool_max_per_route",
                Integer.toString(conf.getTriggerForwardHTTPPOOLMaxPerRoute()))));
    conf.setTriggerForwardMQTTPoolSize(
        Integer.parseInt(
            properties.getProperty(
                "trigger_forward_mqtt_pool_size",
                Integer.toString(conf.getTriggerForwardMQTTPoolSize()))));
  }
load a property file and set TsfileDBConfig variables.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java