diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index aa604395a9a06..1093a9bc04591 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -384,8 +384,8 @@ class Base
     class << self
       def call(env)
         # HACK: For global rescue to have access to the original request and response
-        request = env["actioncontroller.rescue.request"] ||= Request.new(env)
-        response = env["actioncontroller.rescue.response"] ||= Response.new
+        request = env["action_controller.rescue.request"] ||= Request.new(env)
+        response = env["action_controller.rescue.response"] ||= Response.new
         process(request, response)
       end
 
diff --git a/actionpack/lib/action_controller/request.rb b/actionpack/lib/action_controller/request.rb
index 822955d1db7b4..6ac8c6f4a09d7 100755
--- a/actionpack/lib/action_controller/request.rb
+++ b/actionpack/lib/action_controller/request.rb
@@ -19,6 +19,7 @@ class SessionFixationAttempt < StandardError #:nodoc:
 
     def initialize(env)
       @env = env
+      @parser = ActionController::RequestParser.new(env)
     end
 
     %w[ AUTH_TYPE GATEWAY_INTERFACE PATH_INFO
@@ -92,16 +93,15 @@ def headers
 
     # Returns the content length of the request as an integer.
     def content_length
-      @env['CONTENT_LENGTH'].to_i
+      @env["action_controller.request.content_length"] ||= @env['CONTENT_LENGTH'].to_i
     end
-    memoize :content_length
 
     # The MIME type of the HTTP request, such as Mime::XML.
     #
     # For backward compatibility, the post \format is extracted from the
     # X-Post-Data-Format HTTP header if present.
     def content_type
-      Mime::Type.lookup(parser.content_type_without_parameters)
+      Mime::Type.lookup(@parser.content_type_without_parameters)
     end
     memoize :content_type
 
@@ -389,7 +389,7 @@ def path
     # Read the request \body. This is useful for web services that need to
     # work with raw requests directly.
     def raw_post
-      parser.raw_post
+      @parser.raw_post
     end
 
     # Returns both GET and POST \parameters in a single hash.
@@ -418,7 +418,7 @@ def path_parameters
     end
 
     def body
-      parser.body
+      @parser.body
     end
 
     def remote_addr
@@ -431,11 +431,11 @@ def referrer
     alias referer referrer
 
     def query_parameters
-      @query_parameters ||= parser.query_parameters
+      @parser.query_parameters
     end
 
     def request_parameters
-      @request_parameters ||= parser.request_parameters
+      @parser.request_parameters
     end
 
     def body_stream #:nodoc:
@@ -451,7 +451,7 @@ def session
     end
 
     def session=(session) #:nodoc:
-      @session = session
+      @env['rack.session'] = session
     end
 
     def reset_session
@@ -474,9 +474,5 @@ def server_port
       def named_host?(host)
         !(host.nil? || /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.match(host))
       end
-
-      def parser
-        @parser ||= ActionController::RequestParser.new(@env)
-      end
   end
 end
diff --git a/actionpack/lib/action_controller/request_parser.rb b/actionpack/lib/action_controller/request_parser.rb
index 82ee4c84c4fd1..20d53f5d922eb 100644
--- a/actionpack/lib/action_controller/request_parser.rb
+++ b/actionpack/lib/action_controller/request_parser.rb
@@ -2,14 +2,15 @@ module ActionController
   class RequestParser
     def initialize(env)
       @env = env
+      freeze
     end
 
     def request_parameters
-      @request_parameters ||= parse_formatted_request_parameters
+      @env["action_controller.request_parser.request_parameters"] ||= parse_formatted_request_parameters
     end
 
     def query_parameters
-      @query_parameters ||= self.class.parse_query_parameters(query_string)
+      @env["action_controller.request_parser.query_parameters"] ||= self.class.parse_query_parameters(query_string)
     end
 
     # Returns the query string, accounting for server idiosyncrasies.
@@ -90,7 +91,7 @@ def parse_formatted_request_parameters
     end
 
     def content_length
-      @content_length ||= @env['CONTENT_LENGTH'].to_i
+      @env["action_controller.request.content_length"] ||= @env['CONTENT_LENGTH'].to_i
     end
 
     # The raw content type string. Use when you need parameters such as
diff --git a/actionpack/lib/action_controller/rescue.rb b/actionpack/lib/action_controller/rescue.rb
index 8824d983b4f1c..4b7d1e32fdb39 100644
--- a/actionpack/lib/action_controller/rescue.rb
+++ b/actionpack/lib/action_controller/rescue.rb
@@ -60,8 +60,8 @@ def self.included(base) #:nodoc:
 
     module ClassMethods
       def call_with_exception(env, exception) #:nodoc:
-        request = env["actioncontroller.rescue.request"] ||= Request.new(env)
-        response = env["actioncontroller.rescue.response"] ||= Response.new
+        request = env["action_controller.rescue.request"] ||= Request.new(env)
+        response = env["action_controller.rescue.response"] ||= Response.new
         new.process(request, response, :rescue_action, exception)
       end
     end
diff --git a/actionpack/test/controller/request_test.rb b/actionpack/test/controller/request_test.rb
index c93d3152b80fa..02bb2ee890bd5 100644
--- a/actionpack/test/controller/request_test.rb
+++ b/actionpack/test/controller/request_test.rb
@@ -391,8 +391,8 @@ def test_user_agent
   end
 
   def test_parameters
-    @request.instance_eval { @request_parameters = { "foo" => 1 } }
-    @request.instance_eval { @query_parameters = { "bar" => 2 } }
+    @request.stubs(:request_parameters).returns({ "foo" => 1 })
+    @request.stubs(:query_parameters).returns({ "bar" => 2 })
 
     assert_equal({"foo" => 1, "bar" => 2}, @request.parameters)
     assert_equal({"foo" => 1}, @request.request_parameters)
diff --git a/actionpack/test/controller/rescue_test.rb b/actionpack/test/controller/rescue_test.rb
index 8728c9fca3ed8..9f6b45f065821 100644
--- a/actionpack/test/controller/rescue_test.rb
+++ b/actionpack/test/controller/rescue_test.rb
@@ -383,8 +383,8 @@ def test_block_rescue_handler_with_argument_as_string
 
   def test_rescue_dispatcher_exceptions
     env = @request.env
-    env["actioncontroller.rescue.request"] = @request
-    env["actioncontroller.rescue.response"] = @response
+    env["action_controller.rescue.request"] = @request
+    env["action_controller.rescue.response"] = @response
 
     RescueController.call_with_exception(env, ActionController::RoutingError.new("Route not found"))
     assert_equal "no way", @response.body