ConnectionTimeoutError после добавления страницы ошибки 404?

Я видел много решений для этого вопроса, но ничего не решает, пожалуйста, помогите мне в этом! Я получил эту ошибку после добавления html-страницы с ошибкой 404 для моего приложения ruby ​​on rails

ActiveRecord::ConnectionTimeoutError (could not obtain a database connection within 5.000 seconds (waited 5.000 seconds)):
2018-12-22T06:37:29.341798+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in `block in wait_poll'
2018-12-22T06:37:29.341800+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:181:in `loop'
2018-12-22T06:37:29.341802+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:181:in `wait_poll'
2018-12-22T06:37:29.341804+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:136:in `block in poll'
2018-12-22T06:37:29.341806+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
2018-12-22T06:37:29.341808+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:146:in `synchronize'
2018-12-22T06:37:29.341810+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:134:in `poll'
2018-12-22T06:37:29.341812+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:418:in `acquire_connection'
2018-12-22T06:37:29.341814+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
2018-12-22T06:37:29.341816+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
2018-12-22T06:37:29.341818+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
2018-12-22T06:37:29.341820+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
2018-12-22T06:37:29.341821+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
2018-12-22T06:37:29.341823+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
2018-12-22T06:37:29.341825+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
2018-12-22T06:37:29.341827+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
2018-12-22T06:37:29.341829+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_handling.rb:87:in `connection'
2018-12-22T06:37:29.341831+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/query_cache.rb:51:in `restore_query_cache_settings'
2018-12-22T06:37:29.341833+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/query_cache.rb:43:in `rescue in call'
2018-12-22T06:37:29.341834+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/query_cache.rb:32:in `call'
2018-12-22T06:37:29.341836+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:621:in `call'
2018-12-22T06:37:29.341838+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
2018-12-22T06:37:29.341840+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/callbacks.rb:82:in `run_callbacks'
2018-12-22T06:37:29.341841+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
2018-12-22T06:37:29.341843+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
2018-12-22T06:37:29.341845+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
2018-12-22T06:37:29.341847+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
2018-12-22T06:37:29.341849+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:38:in `call_app'
2018-12-22T06:37:29.341850+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:20:in `block in call'
2018-12-22T06:37:29.341852+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:68:in `block in tagged'
2018-12-22T06:37:29.341854+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:26:in `tagged'
2018-12-22T06:37:29.341855+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:68:in `tagged'
2018-12-22T06:37:29.341857+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:20:in `call'
2018-12-22T06:37:29.341858+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/request_id.rb:21:in `call'
2018-12-22T06:37:29.341925+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/methodoverride.rb:21:in `call'
2018-12-22T06:37:29.341928+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/runtime.rb:17:in `call'
2018-12-22T06:37:29.341930+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/cache/strategy/local_cache_middleware.rb:26:in `call'
2018-12-22T06:37:29.341937+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/static.rb:84:in `call'
2018-12-22T06:37:29.341939+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/sendfile.rb:112:in `call'
2018-12-22T06:37:29.341941+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/engine.rb:514:in `call'
2018-12-22T06:37:29.341942+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/application.rb:144:in `call'
2018-12-22T06:37:29.341944+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/lock.rb:17:in `call'
2018-12-22T06:37:29.341945+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/content_length.rb:14:in `call'
2018-12-22T06:37:29.341947+00:00 app[web.1]: vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/handler/webrick.rb:60:in `service'
2018-12-22T06:37:29.341948+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
2018-12-22T06:37:29.341950+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
2018-12-22T06:37:29.341952+00:00 app[web.1]: vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
2018-12-22T06:37:29.341953+00:00 app[web.1]: 

После добавления этой строки в production.rb

config.exceptions_app = self.routes

routes.rb

  get '/404', to: 'errors#not_found'
  get '/422', to: 'errors#unacceptable'

errors.controller.rb

class ErrorsController < ApplicationController
  def not_found
    render :status => 404
  end

  def unacceptable
    render :status => 422
  end


end

Я не уверен, как решить эту проблему, пожалуйста, помогите!