Nginx proxy_no_cache and proxy_cache_bypass

Question

Here's the documentation:

proxy_cache_bypass
Defines conditions under which the response will not be taken from a cache. If at least one value of the string parameters is not empty and is not equal to “0” then the response will not be taken from the cache:
proxy_cache_bypass $cookie_nocache $arg_nocache$arg_comment;
proxy_cache_bypass $http_pragma $http_authorization;
Can be used along with the proxy_no_cache directive.

proxy_no_cache
Defines conditions under which the response will not be saved to a cache. If at least one value of the string parameters is not empty and is not equal to “0” then the response will not be saved:
proxy_no_cache $cookie_nocache $arg_nocache$arg_comment;
proxy_no_cache $http_pragma $http_authorization;
Can be used along with the proxy_cache_bypass directive.

Does that mean if I want to totally exclude something in cache, I should set both proxy_no_cache and proxy_cache_bypass? Is it OK if I only set proxy_cache_bypass?

Answer 1

Yes.

If you just have proxy_cache_bypass set true on pages you don't want cached (eg. logged in users) then they will still be saved into the cache and served to people who should get cached pages (eg. non logged in users).

But setting both proxy_cache_bypass and proxy_no_cache to true means that those users neither receive nor contribute to the cache.