Rails 3 +守護進程gem：查詢模型時出現異常

Question

作爲我的rails項目的一部分，我們將使用守護進程作爲消息隊列偵聽器來執行來自Rails RESTful web服務前端的命令。

爲了便於原型設計，我們使用守護進程gem來創建一個非常簡單的守護進程。現在，這非常簡單。下面是代碼：

require 'rubygems' 
require 'daemons' 

require File.expand_path('../../config/environment', __FILE__) 

Daemons.run_proc('aeon_server') do 
    loop do 
     empires = Empire.all 
     sleep(5) 
    end 
end 

基本上，它需要守護的東西，那麼需要我的Ruby環境，然後啓動到後臺程序。守護進程只是試圖查詢Empires表中的所有內容。然後它再睡一遍。

當它關係到執行「所有」，我得到以下異常：

C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:109:in `write': closed stream (IOError) 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:109:in `block in flush' 
from <internal:prelude>:10:in `synchronize' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:102:in `flush' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:126:in `auto_flush' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:67:in `add' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/buffered_logger.rb:78:in `debug' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/abstract_adapter.rb:206:in `rescue in log' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/abstract_adapter.rb:199:in `log' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/sqlite_adapter.rb:135:in `execute' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/sqlite_adapter.rb:284:in `select' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/connection_adapters/abstract/query_cache.rb:56:in `select_all' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/base.rb:468:in `find_by_sql' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/relation.rb:64:in `to_a' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.7/lib/active_record/relation/finder_methods.rb:143:in `all' 
from C:in `all' 
from script/aeon_server_control.rb:9:in `block (2 levels) in <main>' 
from script/aeon_server_control.rb:7:in `loop' 
from script/aeon_server_control.rb:7:in `block in <main>' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/application.rb:249:in `call' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/application.rb:249:in `block in start_proc' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/application.rb:260:in `call' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/application.rb:260:in `start_proc' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/application.rb:293:in `start' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/controller.rb:73:in `run' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons.rb:195:in `block in run_proc' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/cmdline.rb:109:in `call' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons/cmdline.rb:109:in `catch_exceptions' 
from C:/Ruby/lib/ruby/gems/1.9.1/gems/daemons-1.1.3/lib/daemons.rb:194:in `run_proc' 
from script/aeon_server_control.rb:6:in `<main>' 

任何想法，爲什麼的ActiveSupport拋出此異常？除了需要環境之外，是否還需要額外的步驟來將我的rails環境引導到守護進程？

Answer 1

當進程分叉/產生/不管它被稱爲windows時，關於文件描述符有一些複雜性。

嘗試一個重新實例記錄你Rails.logger =的ActiveSupport做Daemons.run_proc（ 'aeon_server'）後:: BufferedLogger.new（ '/路徑/到/日誌'）