In your settings.py file, add following lines:

MONGODB_DATABASES = {
    "default": {
        "name": database_name,
        "host": database_host,
        "password": database_password,
        "username": database_user,
        "tz_aware": True, # if you using timezones in django (USE_TZ = True)
    },
}

Django allows the use of different backend stores for its sessions. MongoEngine provides a MongoDB-based session backend for Django, which allows you to use sessions in your Django application with just MongoDB. To enable the MongoEngine session backend, ensure that your settings module has 'django.contrib.sessions.middleware.SessionMiddleware' in the MIDDLEWARE_CLASSES field and 'django.contrib.sessions' in your INSTALLED_APPS. From there, all you need to do is add the following line into your settings module:

SESSION_ENGINE = 'django_mongoengine.sessions'
SESSION_SERIALIZER = 'django_mongoengine.sessions.BSONSerializer'

Django provides session cookie, which expires after `SESSION_COOKIE_AGE seconds, but doesn't delete cookie at sessions backend, so 'mongoengine.django.sessions' supports `mongodb TTL <http://docs.mongodb.org/manual/tutorial/expire-data/>_.

pip install -r requirements_example.txt
python manage.py devsrv # fails