diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index 4e39654e5b..94dda4e413 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -13,8 +13,8 @@ module ActiveRecord
   class Railtie < Rails::Railtie
     config.active_record = ActiveSupport::OrderedOptions.new
 
-    config.app_generators.orm :active_record, :migration => true,
-                                              :timestamps => true
+    config.generators.orm :active_record, :migration => true,
+                                          :timestamps => true
 
     config.app_middleware.insert_after "::ActionDispatch::Callbacks",
       "ActiveRecord::QueryCache"
@@ -22,29 +22,14 @@ module ActiveRecord
     config.app_middleware.insert_after "::ActionDispatch::Callbacks",
       "ActiveRecord::ConnectionAdapters::ConnectionManagement"
 
-    config.action_dispatch.rescue_responses.merge!(
-      'ActiveRecord::RecordNotFound'   => :not_found,
-      'ActiveRecord::StaleObjectError' => :conflict,
-      'ActiveRecord::RecordInvalid'    => :unprocessable_entity,
-      'ActiveRecord::RecordNotSaved'   => :unprocessable_entity
-    )
-
     rake_tasks do
-      require "active_record/base"
       load "active_record/railties/databases.rake"
     end
 
-    # When loading console, force ActiveRecord::Base to be loaded
-    # to avoid cross references when loading a constant for the
-    # first time. Also, make it output to STDERR.
-    console do |app|
-      require "active_record/railties/console_sandbox" if app.sandbox?
-      require "active_record/base"
-      ActiveRecord::Base.logger = Logger.new(STDERR)
-    end
-
-    runner do |app|
-      require "active_record/base"
+    # When loading console, force ActiveRecord to be loaded to avoid cross
+    # references when loading a constant for the first time.
+    console do
+      ActiveRecord::Base
     end
 
     initializer "active_record.initialize_timezone" do
@@ -58,16 +43,8 @@ module ActiveRecord
       ActiveSupport.on_load(:active_record) { self.logger ||= ::Rails.logger }
     end
 
-    initializer "active_record.identity_map" do |app|
-      config.app_middleware.insert_after "::ActionDispatch::Callbacks",
-        "ActiveRecord::IdentityMap::Middleware" if config.active_record.delete(:identity_map)
-    end
-
     initializer "active_record.set_configs" do |app|
       ActiveSupport.on_load(:active_record) do
-        if app.config.active_record.delete(:whitelist_attributes)
-          attr_accessible(nil)
-        end
         app.config.active_record.each do |k,v|
           send "#{k}=", v
         end
@@ -78,13 +55,7 @@ module ActiveRecord
     # and then establishes the connection.
     initializer "active_record.initialize_database" do |app|
       ActiveSupport.on_load(:active_record) do
-        db_connection_type = "DATABASE_URL"
-        unless ENV['DATABASE_URL']
-          db_connection_type  = "database.yml"
-          self.configurations = app.config.database_configuration
-        end
-        Rails.logger.info "Connecting to database specified by #{db_connection_type}"
-
+        self.configurations = app.config.database_configuration
         establish_connection
       end
     end
@@ -97,32 +68,21 @@ module ActiveRecord
       end
     end
 
-    initializer "active_record.set_reloader_hooks" do |app|
-      hook = lambda do
-        ActiveRecord::Base.clear_reloadable_connections!
-        ActiveRecord::Base.clear_cache!
-      end
-
-      if app.config.reload_classes_only_on_change
+    initializer "active_record.set_dispatch_hooks", :before => :set_clear_dependencies_hook do |app|
+      unless app.config.cache_classes
         ActiveSupport.on_load(:active_record) do
-          ActionDispatch::Reloader.to_prepare(&hook)
-        end
-      else
-        ActiveSupport.on_load(:active_record) do
-          ActionDispatch::Reloader.to_cleanup(&hook)
+          ActionDispatch::Callbacks.after do
+            ActiveRecord::Base.clear_reloadable_connections!
+          end
         end
       end
     end
 
-    initializer "active_record.add_watchable_files" do |app|
-      config.watchable_files.concat ["#{app.root}/db/schema.rb", "#{app.root}/db/structure.sql"]
-    end
-
     config.after_initialize do
       ActiveSupport.on_load(:active_record) do
         instantiate_observers
 
-        ActionDispatch::Reloader.to_prepare do
+        ActionDispatch::Callbacks.to_prepare(:activerecord_instantiate_observers) do
           ActiveRecord::Base.instantiate_observers
         end
       end