Rails应用程序无法连接到mysql，可以'；t通过套接字连接到本地MySQL服务器'/var/run/mysqld/mysql.sock'；（2） （Mysql2:：错误）

我目前正陷入rails项目的问题（我希望是新手）（这是我的第一个rails项目，如果我错过了任何重要的东西，我道歉）。我已经做了几个小时了，似乎找不到任何解决办法。我尝试了以下线程的解决方案，但没有结果

名单还在继续，不管怎样，有些线索与我的情况相似，其他的只是抓住了救命稻草。让我给你简要介绍一下我的情况

• 该项目是在mac上开发的
  • 我最近设置了一个测试服务器，作为学习部署过程的一种手段
  • 服务器正在运行Ubuntu服务器12.04

我按照一些教程进行了设置，包括部署教程，直到：

$ rake RAILS_ENV=production db:schema:load

这是我第一次遇到无法连接到本地MySQL服务器错误的地方

如果使用--trace运行它，将得到以下输出：

** Invoke db:schema:load (first_time)
** Invoke environment (first_time)
** Execute environment
rake aborted!
Can't connect to local MySQL server through socket '/var/run/mysqld/mysql.sock' (2)
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:277:in `new_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:287:in `checkout_new_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:235:in `block (2 levels) in checkout'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `loop'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `block in checkout'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `checkout'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:374:in `retrieve_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/model_schema.rb:308:in `clear_cache!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/railtie.rb:91:in `block (2 levels) in <class:Railtie>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:418:in `_run__427268845__prepare__407057367__callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:405:in `__run_callback'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:81:in `run_callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `instance_exec'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:55:in `block in run_initializers'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `run_initializers'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:136:in `initialize!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
/var/www/little_oven_deploy/releases/20120705162026/config/environment.rb:5:in `<top (required)>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `block in require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:236:in `load_dependency'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:103:in `require_environment!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:292:in `block (2 levels) in initialize_tasks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:176:in `block in invoke_prerequisites'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `invoke_prerequisites'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/bin/rake:19:in `load'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/bin/rake:19:in `<main>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/bin/ruby_noexec_wrapper:14:in `eval'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:schema:load => environment

/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect': Can't connect to local MySQL server through socket '/var/run/mysqld/mysql.sock' (2) (Mysql2::Error)
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:277:in `new_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:287:in `checkout_new_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:235:in `block (2 levels) in checkout'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `loop'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `block in checkout'
    from /usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `checkout'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:374:in `retrieve_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/model_schema.rb:308:in `clear_cache!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/railtie.rb:91:in `block (2 levels) in <class:Railtie>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:418:in `_run__485859349__prepare__1069885904__callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:405:in `__run_callback'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:81:in `run_callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `instance_exec'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `run'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `each'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `run_initializers'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:136:in `initialize!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /var/www/little_oven_deploy/releases/20120705162026/config/environment.rb:5:in `<top (required)>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `block in require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:103:in `require_environment!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

请注意，我已经更改了socket变量的位置，以与我认为ubuntu上的.sock文件相对应，因为这与mac OSX上的标准安装不同

最后，我在运行时也会遇到同样的错误

rails c

具有以下输出：

** Invoke db:schema:load (first_time)
** Invoke environment (first_time)
** Execute environment
rake aborted!
Can't connect to local MySQL server through socket '/var/run/mysqld/mysql.sock' (2)
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:277:in `new_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:287:in `checkout_new_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:235:in `block (2 levels) in checkout'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `loop'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `block in checkout'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `checkout'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:374:in `retrieve_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/model_schema.rb:308:in `clear_cache!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/railtie.rb:91:in `block (2 levels) in <class:Railtie>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:418:in `_run__427268845__prepare__407057367__callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:405:in `__run_callback'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:81:in `run_callbacks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `instance_exec'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:55:in `block in run_initializers'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `run_initializers'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:136:in `initialize!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
/var/www/little_oven_deploy/releases/20120705162026/config/environment.rb:5:in `<top (required)>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `block in require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:236:in `load_dependency'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:103:in `require_environment!'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:292:in `block (2 levels) in initialize_tasks'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:176:in `block in invoke_prerequisites'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `invoke_prerequisites'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain'
/usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/bin/rake:19:in `load'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@global/bin/rake:19:in `<main>'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/bin/ruby_noexec_wrapper:14:in `eval'
/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:schema:load => environment

/usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect': Can't connect to local MySQL server through socket '/var/run/mysqld/mysql.sock' (2) (Mysql2::Error)
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:277:in `new_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:287:in `checkout_new_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:235:in `block (2 levels) in checkout'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `loop'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in `block in checkout'
    from /usr/share/ruby-rvm/rubies/ruby-1.9.2-p318/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `checkout'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:374:in `retrieve_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/model_schema.rb:308:in `clear_cache!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activerecord-3.2.2/lib/active_record/railtie.rb:91:in `block (2 levels) in <class:Railtie>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:418:in `_run__485859349__prepare__1069885904__callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:405:in `__run_callback'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/callbacks.rb:81:in `run_callbacks'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/actionpack-3.2.2/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `instance_exec'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `run'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `each'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `run_initializers'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:136:in `initialize!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /var/www/little_oven_deploy/releases/20120705162026/config/environment.rb:5:in `<top (required)>'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `block in require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/application.rb:103:in `require_environment!'
    from /usr/share/ruby-rvm/gems/ruby-1.9.2-p318@rails_3_2/gems/railties-3.2.2/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

一些随意的想法：

• 谁是

  /var/run/mysqld/mysql.sock

  的所有者？我知道这是你提到的第一个链接，但也许你错过了。运行命令的用户是否可以访问它

• 可能默认的MySQL端口（

  3306

  ）被阻止了？我想它可能会阻止Rails，即使您在本地运行东西，因为在Unix设计中，端口无处不在。如果您在Amazon上运行，请注意，默认情况下，它们会关闭所有端口（默认情况下会删除所有PING请求，但这是另一个问题），您可能需要单击它们仪表板中的选项

• 尝试将主机：127.0.0.1和端口：3306添加到生产配置设置中

• 尝试删除

  池

  和

  重新连接

  选项，看看会发生什么（这完全是胡乱猜测）

• 这里有一些想法，在这种情况下，您应该卸载

  mysql客户端

  和

  mysql服务器

  软件包，然后重新安装，但我不明白这是为什么

---

您也可以从database.yml中的生产环境中删除套接字规范

production:
  # socket: /var/run/mysqld/mysql.sock

---

我知道性能略有下降，但这让我经历了一个类似的问题。

/tmp/mysqld.sock

是OSX套接字的位置

在LinuxMint/Ubuntu上，它应该位于

/var/run/mysqld/mysql.sock

如果不是，那么该位置应该在一个MySQL配置文件中引用，名为

my.cnf

。如果输入，这些文件的位置和加载顺序将打印出来

mysql--help

进入终点站。如果在指定的路径中找不到

my.cnf

文件，则该文件不存在，因此请忽略它，并查看加载顺序中的下一个文件

^这是验证socks配置的简单、可靠的方法

Josh Lewis的回答应该是正确的，因为我的Rails 4.0.3安装默认忽略套接字行-因此我假设它是预定义的或由安装自动配置的，您不必担心这一点

这不是一个老生常谈的问题，但它在谷歌搜索中名列榜首。

$mysqld

f错误“mysql文件”目录

$sudo mkdir/var/lib/mysql文件

$sudo chown-R mysql:mysql/var/lib/mysql文件/

---

$sudo chmod 700/var/lib/mysql files/

在Ubuntu服务器上运行“locate mysql.sock”时，是否返回“/var/run/mysqld/mysql.sock”？另外，你确定Rails正在加载database.yml文件吗？@Ryan，事实上我确实尝试了查找mysql.sock，但它没有返回任何内容，这就是为什么我将它连接到mysqld.sock，不过这只是一个（未经）教育的猜测。关于建立yml文件的加载，我怎么知道呢？不，等等。。。我想Amazon阻塞端口不应该是个问题。但是你可以检查一下，我对EC2没有太多的经验，也不知道他们的自定义防火墙是如何工作的，无论是外部还是内部。这是有效的，在评论了你的建议之后，我可以运行rake命令，

$rake RAILS\u ENV=production db:schema:load

但是

RAILS c

仍然抛出相同的错误。我现在也在开发部分对相同的

socket:

规范进行了注释，控制台现在工作正常。你能解释一下为什么会这样吗？撇开性能问题不谈，这种策略还有其他陷阱吗？据我所知，当数据库和应用程序位于同一台服务器上时，您可以通过Unix套接字连接到MySQL。这通常比通过TCP连接要快。然而，较大规模的应用程序通常将数据库放在不同的服务器上，在这种情况下使用TCP。我的观点是，这很可能不值得注意。@Promethean_Sin

rails c

以开发模式运行控制台。使用rails c production以生产模式运行它。这就是为什么您的控制台（在开发模式下）在开发部分取消注释后开始工作的原因。谢谢，有更多关于这方面的信息总是很好的。虽然我后来进入了Postgresql，但我相信它会在未来帮助人们。这救了我。。谢谢