Rails 3+ Daemons gem:查询模型时出现异常

Question

作为我的rails项目的一部分，我们将使用一个守护进程作为消息队列侦听器来执行来自Rails RESTful we服务前端的命令。

为了简化原型设计，我们使用Daemons gem来创建一个非常简单的守护进程。现在，这非常简单。代码如下：

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，它需要用于守护进程的东西，然后需要我的Ruby环境，然后启动到守护进程。守护进程只是尝试查询Empires表中的所有内容。然后它就会睡着，然后再睡一次。

当它执行'all‘时，我得到了以下异常：

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>'

你知道为什么ActiveSupport会抛出这个异常吗？除了需要环境之外，是否还有其他步骤需要将我的rails环境“引导”到守护进程中？

Answer 1

当进程为forked/spawned/whatever-it-is-called-on-windows.时，关于文件描述符有一些复杂之处

尝试在使用ActiveSupport::BufferedLogger.new('/path/to/log') =ActiveSupport：：BufferedLogger.new(‘/path/to/log’)执行Daemons.run_proc('aeon_server')之后重新实例化记录器