How do I disable cache?

edit

I'm trying disable cache and not working. I use 'dummy' cache, but I get error.

root@webhost2:/var/www/ask# ./manage.py runserver 10.0.0.34:8000
Validating models...

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/askbot-0.7.43-py2.7.egg/askbot/deps/livesettings/values.py", line 306, in _value
    val = self.setting.value
  File "/usr/local/lib/python2.7/dist-packages/askbot-0.7.43-py2.7.egg/askbot/deps/livesettings/values.py", line 288, in _setting
    return find_setting(self.group.key, self.key)
  File "/usr/local/lib/python2.7/dist-packages/askbot-0.7.43-py2.7.egg/askbot/deps/livesettings/models.py", line 37, in find_setting
    setting = cache_get(ck)
  File "/usr/local/lib/python2.7/dist-packages/django_keyedcache-1.4_6-py2.7.egg/keyedcache/__init__.py", line 184, in cache_get
    cache_require()
  File "/usr/local/lib/python2.7/dist-packages/django_keyedcache-1.4_6-py2.7.egg/keyedcache/__init__.py", line 298, in cache_require
    raise CacheNotRespondingError()
CacheNotRespondingError
("Startup error, couldn't load EXTERNAL_KEYS.RECAPTCHA_SECRET", None)
0 errors found
Django version 1.3.1, using settings 'ask.settings'
Development server is running at http://10.0.0.34:8000/
Quit the server with CONTROL-C.