Ruby on Rails application could not be started

These are the possible causes:
  • There may be a syntax error in the application's code. Please check for such errors and fix them.
  • A required library may not installed. Please install all libraries that this application requires.
  • The application may not be properly configured. Please check whether all configuration files are written correctly, fix any incorrect configurations, and restart this application.
  • A service that the application relies on (such as the database server or the Ferret search engine server) may not have been started. Please start that service.
Further information about the error may have been written to the application's log file. Please check it in order to analyse the problem.
Error message:
Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2) (Mysql2::Error)
Exception class:
PhusionPassenger::UnknownError
Application root:
/var/www/omoshiro-apps.com
Backtrace:
# File Line Location
0 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.11/lib/mysql2/client.rb 44 in `connect'
1 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.11/lib/mysql2/client.rb 44 in `initialize'
2 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql2_adapter.rb 16 in `new'
3 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql2_adapter.rb 16 in `mysql2_connection'
4 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 309 in `new_connection'
5 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 319 in `checkout_new_connection'
6 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 241 in `block (2 levels) in checkout'
7 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 236 in `loop'
8 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 236 in `block in checkout'
9 /usr/local/lib/ruby/1.9.1/monitor.rb 211 in `mon_synchronize'
10 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 233 in `checkout'
11 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 96 in `block in connection'
12 /usr/local/lib/ruby/1.9.1/monitor.rb 211 in `mon_synchronize'
13 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 95 in `connection'
14 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb 404 in `retrieve_connection'
15 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb 170 in `retrieve_connection'
16 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb 144 in `connection'
17 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/model_schema.rb 223 in `table_exists?'
18 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.8/lib/active_record/attribute_methods.rb 129 in `attribute_names'
19 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.8/lib/action_controller/metal/params_wrapper.rb 173 in `_set_wrapper_defaults'
20 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.8/lib/action_controller/metal/params_wrapper.rb 133 in `inherited'
21 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.8/lib/abstract_controller/railties/routes_helpers.rb 7 in `block (2 levels) in with'
22 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.8/lib/action_controller/railties/paths.rb 7 in `block (2 levels) in with'
23 /var/www/omoshiro-apps.com/app/controllers/big_controller.rb 2 in `'
24 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 251 in `require'
25 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 251 in `block in require'
26 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 236 in `load_dependency'
27 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 251 in `require'
28 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 359 in `require_or_load'
29 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 313 in `depend_on'
30 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb 225 in `require_dependency'
31 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/engine.rb 439 in `block (2 levels) in eager_load!'
32 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/engine.rb 438 in `each'
33 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/engine.rb 438 in `block in eager_load!'
34 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/engine.rb 436 in `each'
35 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/engine.rb 436 in `eager_load!'
36 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/application/finisher.rb 53 in `block in '
37 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb 30 in `instance_exec'
38 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb 30 in `run'
39 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb 55 in `block in run_initializers'
40 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb 54 in `each'
41 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb 54 in `run_initializers'
42 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/application.rb 136 in `initialize!'
43 /var/www/omoshiro-apps.com/vendor/bundle/ruby/1.9.1/gems/railties-3.2.8/lib/rails/railtie/configurable.rb 30 in `method_missing'
44 /var/www/omoshiro-apps.com/config/environment.rb 5 in `'
45 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/classic_rails/application_spawner.rb 222 in `require'
46 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/classic_rails/application_spawner.rb 222 in `preload_application'
47 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/classic_rails/application_spawner.rb 181 in `block in initialize_server'
48 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/utils.rb 563 in `report_app_init_status'
49 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/classic_rails/application_spawner.rb 174 in `initialize_server'
50 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server.rb 204 in `start_synchronously'
51 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server.rb 180 in `start'
52 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/classic_rails/application_spawner.rb 149 in `start'
53 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/spawn_manager.rb 219 in `block (2 levels) in spawn_rails_application'
54 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server_collection.rb 132 in `lookup_or_add'
55 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/spawn_manager.rb 214 in `block in spawn_rails_application'
56 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server_collection.rb 82 in `block in synchronize'
57 prelude> 10:in `synchronize'
58 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server_collection.rb 79 in `synchronize'
59 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/spawn_manager.rb 213 in `spawn_rails_application'
60 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/spawn_manager.rb 132 in `spawn_application'
61 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/spawn_manager.rb 275 in `handle_spawn_application'
62 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server.rb 357 in `server_main_loop'
63 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/lib/phusion_passenger/abstract_server.rb 206 in `start_synchronously'
64 /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.15/helper-scripts/passenger-spawn-server 99 in `
'