Delayed_job 3.0.0 在控制台中工作，但在 WEBrick 中不起作用

Question

环境：

  Rails => 3.1.0
  delayed_job => 3.0.1
  delayed_job_active_record => 0.3.1
  WEBrick => 1.3.1
  ruby => 1.9.2

代码：

class Comment < ActiveRecord::Base
  def tweet(tweet_msg)
    client = Twitter::Client.new
    client.update(tweet_msg)
  end

  after_save :tweet_comment
  def tweet_comment
    self.delay.tweet('test tweet')
  end
end

控制台：

从控制台，我将以下内容插入到delayed_jobs 表中，并调用tweet_as_site 函数。一切工作正常......

  SQL (0.5ms)  INSERT INTO `delayed_jobs` (`attempts`, `created_at`, `failed_at`, `handler`, `last_error`, `locked_at`, `locked_by`, `priority`, `queue`, `run_at`, `updated_at`) VALUES (0, '2012-01-25 21:21:48', NULL, '--- !ruby/object:Delayed::PerformableMethod\nobject: !ruby/ActiveRecord:Comment\n attributes:\n id: 121\n title: \'\'\n comment: aa\n commentable_id: 2296\n commentable_type: Game\n user_id: 1\n created_at: 2012-01-25 21:19:19.000000000Z\n updated_at: 2012-01-25 21:19:19.000000000Z\nmethod_name: :tweet\nargs:\n- test tweet\n', NULL, NULL, NULL, 0, NULL, '2012-01-25 21:21:48', '2012-01-25 21:21:48')

Log:
  2012-01-25T13:21:52-0800: [Worker(delayed_job host:ubuntu pid:13063)] Comment#tweet completed after 1.6850
  2012-01-25T13:21:52-0800: [Worker(delayed_job host:ubuntu pid:13063)] 1 jobs processed at 0.5913 j/s, 0 failed ...

然后，当我通过 WEBrick 网络服务器执行此操作时，以下 sql 被插入到elasted_jobs表中......

  SQL (0.4ms)  INSERT INTO `delayed_jobs` (`attempts`, `created_at`, `failed_at`, `handler`, `last_error`, `locked_at`, `locked_by`, `priority`, `queue`, `run_at`, `updated_at`) VALUES (0, '2012-01-25 21:19:19', NULL, '--- !ruby/object:Delayed::PerformableMethod\nattributes:\n id: 121\n title: \'\'\n comment: aa\n commentable_id: 2296\n commentable_type: Game\n user_id: 1\n created_at: 2012-01-25 21:19:19.759253106Z\n updated_at: 2012-01-25 21:19:19.759253106Z\n', NULL, NULL, NULL, 0, NULL, '2012-01-25 21:19:19', '2012-01-25 21:19:19')
Log:
  2012-01-25T13:19:20-0800: [Worker(delayed_job host:ubuntu pid:13063)] NilClass# completed after 0.0083
  2012-01-25T13:19:20-0800: [Worker(delayed_job host:ubuntu pid:13063)] 1 jobs processed at 55.5559 j/s, 0 failed ...

来自控制台的插入包括“method_name: :tweet\nargs:\n- test tweet”处理程序 yaml，但是从 WEBrick 执行时该部分丢失。

一些注意事项...

1. 我已经尝试过使用 .delay 和 handle_asynchronously 但都不起作用。
2. 对于某些对象（例如 Twitter::Client），它确实可以与 WEBrick 一起使用，但它不适用于我自己的模型。