I am running a Squid (3.1) cache in front of Django. The content of the site does not change very often, so Squid gives our backend much needed breathing room. Currently, this is the refresh pattern that we are using to cache the content: refresh_pattern . 60 100% 60 We basically want to cache everything for at least an hour (and only an hour) before Squid then re-validates the content. My question is on the "100%" parameter, which sets the lm-factor. I'm not sure if setting that to 100% is doing what we want it to. The assumption was that by setting it to 100%, it would ensure that objects stay in the cache for the max cache time. Is this an incorrect assumption? What are the best practices that one should follow when setting up a refresh pattern like this?