[
  {dns_proxy, [

    %% 公共的dns域名解析服务
    {public_dns_servers, [
      {{8,8,8,8}, 53},
      {{8,8,8,8}, 53}
    ]},

    {dns_resolver_pool, [
      {size, 200},
      {max_overflow, 1000},
      {worker_module, dns_resolver}
    ]}

  ]},

  %% 系统日志配置，系统日志为lager, 支持日志按日期自动分割
  {lager, [
    {colored, true},
    %% Whether to write a crash log, and where. Undefined means no crash logger.
    {crash_log, "trade_hub.crash.log"},
    %% Maximum size in bytes of events in the crash log - defaults to 65536
    {crash_log_msg_size, 65536},
    %% Maximum size of the crash log in bytes, before its rotated, set
    %% to 0 to disable rotation - default is 0
    {crash_log_size, 10485760},
    %% What time to rotate the crash log - default is no time
    %% rotation. See the README for a description of this format.
    {crash_log_date, "$D0"},
    %% Number of rotated crash logs to keep, 0 means keep only the
    %% current one - default is 0
    {crash_log_count, 5},
    %% Whether to redirect error_logger messages into lager - defaults to true
    {error_logger_redirect, true},

    %% How big the gen_event mailbox can get before it is switched into sync mode
    {async_threshold, 20},
    %% Switch back to async mode, when gen_event mailbox size decrease from `async_threshold'
    %% to async_threshold - async_threshold_window
    {async_threshold_window, 5},

    {handlers, [
      %% debug | info | warning | error, 日志级别
      {lager_console_backend, debug},
      {lager_file_backend, [{file, "debug.log"}, {level, debug}, {size, 314572800}]},
      {lager_file_backend, [{file, "notice.log"}, {level, notice}, {size, 314572800}]},
      {lager_file_backend, [{file, "error.log"}, {level, error}, {size, 314572800}]},
      {lager_file_backend, [{file, "info.log"}, {level, info}, {size, 314572800}]}
    ]}
  ]}
].