3 files changed, 16 insertions, 8 deletions
diff --git a/railties/CHANGELOG b/railties/CHANGELOG
index b015d92060..3f77a2f37b 100644
--- a/railties/CHANGELOG
+++ b/railties/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Changed the default logger from Ruby's own Logger with the clean_logger extensions to ActiveSupport::BufferedLogger for performance reasons [DHH]. (You can change it back with config.logger = Logger.new("/path/to/log", level).)
+
 * Added a default 422.html page to be rendered when ActiveRecord::RecordInvalid, ActiveRecord::RecordNotSaved, or ActionController::InvalidAuthenticityToken is raised [DHH]
 
 * Added --skip-fixture option to script/generate model #6862 [sandofsky]
diff --git a/railties/lib/dispatcher.rb b/railties/lib/dispatcher.rb
index cb1289957e..398acb7e97 100644
--- a/railties/lib/dispatcher.rb
+++ b/railties/lib/dispatcher.rb
@@ -38,13 +38,14 @@ class Dispatcher
         controller = ActionController::Routing::Routes.recognize(request)
         controller.process(request, response).out(output)
       end
-    rescue Exception => exception  # errors from CGI dispatch
+    rescue Exception => exception # errors from CGI dispatch
       failsafe_response(cgi, output, '500 Internal Server Error', exception) do
         controller ||= (ApplicationController rescue ActionController::Base)
         controller.process_with_exception(request, response, exception).out(output)
       end
     ensure
-      # Do not give a failsafe response here.
+      # Do not give a failsafe response here
+      flush_logger
       reset_after_dispatch
     end
 
@@ -165,9 +166,13 @@ class Dispatcher
         if defined?(RAILS_DEFAULT_LOGGER) && !RAILS_DEFAULT_LOGGER.nil?
           RAILS_DEFAULT_LOGGER
         else
-          Logger.new($stderr)
+          ActiveSupport::BufferedLogger.new($stderr)
         end
       end
+      
+      def flush_logger
+        RAILS_DEFAULT_LOGGER.flush if defined?(RAILS_DEFAULT_LOGGER) && RAILS_DEFAULT_LOGGER.respond_to?(:flush)
+      end
   end
 end
 
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index b9fa9eee01..c2862ee443 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -240,11 +240,12 @@ module Rails
 
       unless logger = configuration.logger
         begin
-          logger = Logger.new(configuration.log_path)
-          logger.level = Logger.const_get(configuration.log_level.to_s.upcase)
-        rescue StandardError
-          logger = Logger.new(STDERR)
-          logger.level = Logger::WARN
+          logger = ActiveSupport::BufferedLogger.new(configuration.log_path)
+          logger.level = ActiveSupport::BufferedLogger.const_get(configuration.log_level.to_s.upcase)
+          logger.auto_flushing = false if configuration.environment == "production"
+        rescue StandardError =>e
+          logger = ActiveSupport::BufferedLogger.new(STDERR)
+          logger.level = ActiveSupport::BufferedLogger::WARN
           logger.warn(
             "Rails Error: Unable to access log file. Please ensure that #{configuration.log_path} exists and is chmod 0666. " +
             "The log level has been raised to WARN and the output directed to STDERR until the problem is fixed."