django + mod_wsgi +apache

Question

Hi. When I run my django project on apache with mod_wsgi, I receive something like that:

    [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145] Traceback (most recent call last):
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/core/handlers/wsgi.py", line 245, in __call__
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     response = middleware_method(request, response)
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/middleware.py", line 28, in process_response
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     if request.session.get_expire_at_browser_close():
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/backends/base.py", line 229, in get_expire_at_browser_close
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     if self.get('_session_expiry') is None:
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/backends/base.py", line 63, in get
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     return self._session.get(key, default)
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/backends/base.py", line 172, in _get_session
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     self._session_cache = self.load()
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/backends/db.py", line 18, in load
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     return self.decode(force_unicode(s.session_data))
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/site-packages/Django-1.1.1-py2.6.egg/django/contrib/sessions/backends/base.py", line 93, in decode
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     encoded_data = base64.decodestring(session_data)
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]   File "/usr/local/lib/python2.6/base64.py", line 321, in decodestring
        [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145]     return binascii.a2b_base64(s)
 [Wed Mar 10 08:46:43 2010] [error] [client 10.13.1.145] Error: Incorrect padding

Is there any suggestion, clue or solution?

Answer 1

Sounds like one of the entries in the django_session table might be malformed. Either inspect the table and remove the broken row, or you can truncate the table altogether if you can live with that.

Answer 2

Here are a few suggestions for places to look:

1. Your paths in the traceback point to /usr/local/lib/python2.6/ ... maybe you built mod_wsgi with a different version of Python, especially the system installed version probably in /usr/lib/pythonX.X. When building mod_wsgi you need to use this:

   ./configure --with-python=/usr/local/bin/python2.6

2. Check your apache error log to see if there are any useful messages in there, especially ones that are documented at mod_wsgi Installation Issues.

3. When you run syncdb, even for the "first time", are you seeing messages about the auth tables being created? Maybe you still have an old auth table in your database and can fix the problem by completely dropping the database and starting from scratch (or doing something like manage.py reset