如何覆盖流利的输出插件的chunk_limit_size

Question

我正在编写一个Fluentd输出插件（处于缓冲模式），并且想覆盖chunk_limit_size参数。为此，我在fluentd conf文件中设置参数，如下所示

Conf is 
   <buffer tag>
      @type file
      path                /tmp/
      flush_interval      30s
      chunk_limit_size    256m
    </buffer>

检查o / p（在缓冲区配置对象上）是

<Fluent::Config::Section {"chunk_keys":["tag"],"@type":"file","timekey":null,"timekey_wait":600,"timekey_use_utc":false,"timekey_zone":"-0800","flush_at_shutdown":null,"flush_mode":"default","flush_interval":30,"flush_thread_count":10,"flush_thread_interval":0.5,"flush_thread_burst_interval":0.05,"delayed_commit_timeout":60,"overflow_action":"block","retry_forever":false,"retry_timeout":259200,"retry_max_times":17,"retry_secondary_threshold":0.8,"retry_type":"exponential_backoff","retry_wait":2,"retry_exponential_backoff_base":2,"retry_max_interval":null,"retry_randomize":true,"disable_chunk_backup":true,"type":"file","chunk_limit_size":1048576,"chunk_limit_records":50,"total_limit_size":5368709120}>

我们可以看到，chunk_limit_size设置为1048576。这是我在代码中为此参数设置的默认值。它不会被我在fluentd conf文件中设置的值覆盖。我在这里想念东西吗？