Fixed #13200 -- Updated the DB session backend to make full use of routers,…

Fixed #13200 -- Updated the DB session backend to make full use of routers, deprecating the need for the SESSION_DB_ALIAS setting. Thanks to rokclimb15 for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12844 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/sessions/backends/db.py

@@ -3,7 +3,7 @@ from django.conf import settings
 from django.contrib.sessions.models import Session
 from django.contrib.sessions.backends.base import SessionBase, CreateError
 from django.core.exceptions import SuspiciousOperation
-from django.db import IntegrityError, transaction, DEFAULT_DB_ALIAS
+from django.db import IntegrityError, transaction, router
 from django.utils.encoding import force_unicode
 
 class SessionStore(SessionBase):
@@ -11,7 +11,6 @@ class SessionStore(SessionBase):
     Implements database session store.
     """
     def __init__(self, session_key=None):
-        self.using = getattr(settings, "SESSION_DB_ALIAS", DEFAULT_DB_ALIAS)
         super(SessionStore, self).__init__(session_key)
 
     def load(self):
@@ -58,12 +57,13 @@ class SessionStore(SessionBase):
             session_data = self.encode(self._get_session(no_load=must_create)),
             expire_date = self.get_expiry_date()
         )
-        sid = transaction.savepoint(using=self.using)
+        using = router.db_for_write(Session, instance=obj)
+        sid = transaction.savepoint(using=using)
         try:
-            obj.save(force_insert=must_create)
+            obj.save(force_insert=must_create, using=using)
         except IntegrityError:
             if must_create:
-                transaction.savepoint_rollback(sid, using=self.using)
+                transaction.savepoint_rollback(sid, using=using)
                 raise CreateError
             raise
 

docs/ref/settings.txt

@@ -1299,18 +1299,6 @@ See the :ref:`topics-http-sessions`.
 
 .. setting:: SESSION_EXPIRE_AT_BROWSER_CLOSE
 
-SESSION_DB_ALIAS
-----------------
-
-.. versionadded:: 1.2
-
-Default: ``None``
-
-If you're using database-backed session storage, this selects the database
-alias that will be used to store session data. By default, Django will use
-the ``default`` database, but you can store session data on any database
-you choose.
-
 SESSION_EXPIRE_AT_BROWSER_CLOSE
 -------------------------------
 

docs/topics/http/sessions.txt

@@ -44,16 +44,9 @@ Using database-backed sessions
 If you want to use a database-backed session, you need to add
 ``'django.contrib.sessions'`` to your ``INSTALLED_APPS`` setting.
 
-If you want to store your session data on a database other than ``default``
-alias, you should set the :setting:`SESSION_DB_ALIAS` setting.
-
 Once you have configured your installation, run ``manage.py syncdb``
 to install the single database table that stores session data.
 
-.. versionadded:: 1.2
-   The :setting:`SESSION_DB_ALIAS` setting was added in Django 1.2. It
-   is not required in earlier versions.
-
 Using cached sessions
 ---------------------