====================================== Front-end caching and session back end ====================================== Front-end caching ~~~~~~~~~~~~~~~~~ We do not recommend using front-end caching tools with the dashboard. The dashboard is rendering dynamic content resulting directly from OpenStack API requests and front-end caching layers such as varnish can prevent the correct content from being displayed. In Django, static media is directly served from Apache or :term:`Nginx` and already benefits from web host caching. Session back end ~~~~~~~~~~~~~~~~ The default session back end for horizon (``django.contrib.sessions.backends.signed_cookies``) saves user data in signed, but unencrypted cookies stored in the browser. Due to the fact that each dashboard instance is stateless, the previously mentioned methodology provides the ability to implement the most simple session back-end scaling. It should be noted that with this type of implementation sensitive access tokens will be stored in the browser and will be transmitted with each request made. The back end ensures the integrity of session data, even though the transmitted data is only encrypted by HTTPS. If your architecture allows it, we recommend using ``django.contrib.sessions.backends.cache`` as your session back end with memcache as the cache. Memcache must not be exposed publicly, and should communicate over a secured private channel. If you choose to use the signed cookies back end, refer to the Django documentation to understand the security trade-offs. For further details, see the `Django documentation `_.